Yoeddynzs 1965 Hillman imp - back to Datsun engine for now and its all legal beagle again...

[yoeddynz]

Flat six in

Cut away under the seat base and the tunnel as per on the green imp. 

The air saw was so perfect for much of this job which means much less grinding dust everywhere.

I've marked out where I'll cut away a little bit more. I'd rather give it extra clearance now than ending up with it potentially knocking against the steel on a bumpy road etc later.

Cut off a couple of superfluous tabs sticking up on the transmission for the same reasons as above.

Oh I also couldn't resist a photo of the two power plants next to each other.  It's hard to gauge sizes from the pic though as the Datsuns wheely stand 2000 is much lower.

[yoeddynz]

Sealing up the cut out tunnel top and under the rear seat was to be the next stage but first I decided to make some new beefed up engine mounts. The originals I had made from a mixture of 3 and 4mm steel were probably fine but i wanted to move the crossmember backwards away from the engine for a little bit more clearance. So while I was at it I thought it best to use thicker steel.

To start with I made a jig based off the original mounts. Now there were datum points to build to, allowing for extra clearance while I was at it.

I popped into G3 engineering where I get a lot of my steel offcuts from and grabbed some 4mm plate. I had 5mm at home for the main backing plates.

Used the hefty steel bender..

Tigged the majority of the welds except the inside ones I couldn't reach which got mig welded. Plenty of heat. These wont fail.

Added gussets just to be sure...

The new mounts now set the crossmember further back by about 5mm.  I could now drill the holes through the chassis rails.  I made up a new pair of backing plates with extra holes and captive nuts.  The plates extend further forwards to line up with the holes that Datsun crossmember bolts through.  I can now easily bolt in either crossmember.

I was super happy to discover that due to the flat six being only 3 cylinders long I have enough room to pull the engine back so its gearbox bobbins are clear of the gearbox crossmember. I can then raise the car up and away from the engine, all without having to remove the rear bumper and valance.

Now the engine was in its final position I could replace the lid on the tunnel, now 50mm higher. I started with this bit and had to cut out a section to allow for access to the toyota spec gearbox speedo sensor plug...

Making sure there was ample clearance all round so the box cant knock the tinwork on rough roads I proceeded to box the tunnel back in...

Kneeling down on folded up bits of foam and towels was my home for the next few hours...

Cardboard trials, then steel, cut, trim, tack, check, weld...

Finally boxed in. Another access hole let in so I can get to the top universal joint and lube the gearbox selector shaft.

It was a very good part of the build to finish. Seeing it all sealed up, strong again. I have yet to check the rear seat squab but I feel confident it'll fit with some modifications to the wire frame within.

Underneath looked neat...

Hannah has now painted the tunnel inside and out with Epoxy paint.

After I have finished any other little fabrication bits or hole filling/drilling in the engine bay I'll give it a flick of blue paint (hopefully not making everything else in the workshop blue like the first time)

Now it was onto the rear suspension arms. I am using the set that came on the green imp 2. Surface rust needed wire brushing off outside...

Painted with KBS rust seal  (Aussie por 15 clone)..

Another bit I could have got away without doing but I thought best to make while I'm under the car was this brace...

Pulling up tight to the floor via spreader plates under the seat base...

I have added it to brace the floor halves inline to help keep the suspension mounts inline during hard corning. Like said, I'm not sure if its essential but it might just help avoid any weird effects like rear steering. I know its a bit ugly but hey, at least its hidden under the car.

On the subject of bracing I also made this little brace...

To help stiffen the top of the tunnel near the shifter so it doesn't flex. again, not really needed but I do want a really positive shift action without an excess movement.

So now my next job is to run out the brake/clutch/fuel pipes back along the tunnel and then reassemble the rear suspension so I can setup the handbrake cables. I'll have to paint some bits too. The crossmember, mounts, fuel tank etc. The work area looks like this with bits everywhere...

In other news we had these treats turn up in the mail, a surprise present from my brother in Wales...

He had gone to a big collectables/toy and model show local to him where he then spent a good amount of time asking at the various collectors stalls for any Hillman Imp models and found what is quite a rare and sought after Dinky toy car...

Plus a cool little Imp police car ..

They turned up in the post yesterday as a surprise and made our evening. Very cool. Thanks bro!

[yoeddynz]

So many little jobs that add up to suck time. But its a fun time to be at and there's no point in rushing it.

The rear seat base was next up because I needed to work out where I could run the engine loom through. I tried the base in place, got an idea of how its steel rod framework needed to be adjusted and set to it.

As you might spot in the above pic I also gave myself a decent cut from something sharp in there.

Seat base now fits in neatly although it wont be a luxurious softly sprung seat for a middle passenger when 5 up.  Highly unlikely scenario that is an Imp though.

Megasquirt and associated fuses/relays etc are tucked away under the seat.

I made some mounts for the exhaust box..

Welded the mounts in place and I was then able to tack, then weld the secondaries to their flanges.

I painted the crossmember after having added some handbrake cable guides. Then it and the rear suspension was all bolted up in place. The new driveshafts fitted and hubs pulled on, wheels bolted up and it was rolling again. So it got rolled out the back to join green imp so I could use the hoist to do a customers van job.

As soon as the van was fixed and out of the shop I put Impy back up on the hoist. I then worked out the final section of pipework for the clutch's concentric slave cylinder (CSC). I wanted the bleed nipple to be easier to access and not have any spillage running down into the bellhousing. I made some pipework and fittings to suit.

Bench was covered in brake fitting stuff and I pieced together a system.

I made one setup, tested the clutch and while it worked fine I wasn't happy with the pipes sticking up in the way so I changed a it again leading to the final iteration..

The csc itself was a unit I'd scored from a Ford Mundano engine and gearbox I had well over 6 years ago. Intended to fit the duratec into my Viva wagon. Sold the engine and kept the release bearing just because I thought it might be handy.  So six years I've had it laying about and before that it was residing in a wreckers yard. It must surely be a bit cruddy inside?

 They are not designed to be serviceable but they are also stupidly priced here in NZ - like triple what they cost in the UK.  So I decided it was going to be serviceable and I took it apart. Sure enough it had some mild corrosion marks on luckily what is a stainless guide tube but otherwise actually pretty good.

It cleaned up well in the lathe..

Its a very nicely made thing and quite simple but has to be mounted correctly.  This guide tube seals on the mounting plate with a thin square section seal.

I made a new bigger mount to support the base because the original machined support I'd made wasn't broad enough. I was then able to add two more bolts to sandwich the lot together so that square seal remains squished evenly at all times, as it would in a OEM situation.

We trial fitted it all with the new base plate and pipework. I was not sure whether my stock Imp 5/8" bore master cylinder was going to move enough fluid to get the release bearing travel I needed and I was prepared that I might have had to fit a 3/4" M/C.  However it all seems fine with a light pedal and the bite point is about midway. Very smooth motion too!

While this lot was being done Hannah finished prepping the rear valance for paint. On a nice warm morning I set up  the paint frame outside and sprayed some blue about..

I did my best not to paint the cat blue..

It turned out fine..

Another little fun job was cleaning up the gearstick shaft in the lathe..

...and discovering that universal steering rack boots make for neat gearstick boots...

I'd bought some muffler packing sheet and then played with scissors...

I then painted it with stove paint and sat it on the burner to help it harden. It looks much better in black. I've used silicone to seal the lid. Ran some beads, let them set for a couple of hours till at the point where it squishes flat without smearing. Stainless bolts carefully pulled up evenly. Seems all good but only time will tell on how the seal lasts. Like a few things on this build its a bit experimental.

Gaskets for the inlets and tailpipes are copper. I have quite a bit of decent thick walled copper pipe from the Imp racecar cooling system. Chopped some bits, flattened out, heated and quenched with the oxycet and now nice and soft.

Exhaust all mounted and engine now ready to go in for the final time (he says..)

I just had to get a few more pics of this stage because its a point I've been looking forward to

Positioning the power plant under the car.jpg

Yep. Getting very close now!!!

[yoeddynz]

I will try to keep updates coming along a bit closer now as I tick off many of those little jobs.

The useful alloy scooter handle bar thing I'd picked up at the dump ages ago is getting shorter and shorter. It happens to be 32mm OD and ideal for many jobs such as extending the sensor housing so I could add a 16mm tee for my header tank..

Another bunch of little bits to do was the air filter mount and associated points to feed the IACV, the catch can and a place for the air temp sensor. I made an alloy mount which bolts to the firewall in about the only place left that would fit it. It connects to the throttle body by flexible ducting.

The Goldwing engine just has a simple breather system. The crankcase is under a constant light vacuum and any blowby fumes are drawn straight into the air box before the carbs. I decided ages ago I would just replicate it. I machined up a Ventura...

Oh. Hang on. That's not right.

I mean Venturi...

with some other bits..

Looks like this inside...

I made a little stainless catch can with shelves and stainless scrubbers - for scrubbing out any oil mist. It has a drain plug which is easy to get to.

Painted it black so it hides better (not exactly a pretty thing)

It, along with the filter and filter mount plus associated tubing all resides at the back of the engine bay, luckily out of sight because its all a bit messy. I tried my best without getting too carried away. Its tight in there!..

The two main plugs plus the wideband plug are tucked up nearby..

Also nicked the oil pressure sensor from the Datsun engine and fitted it in place...

Lifted the big folder into place and bent some steel sheet ...

...to cover the hole that normally has a Datsun cylinder head poking through it...

Used rivnuts so now it simply bolts down in place.

I'll glue foam on top so it'll match the rest of the parcel shelf. I'll eventually cover that with an easily removable carpet mat. Its super handy having this access hatch.  As for the underside - that will get painted blue for now and I'll be looking into some sort of cover that simply screws in place, possibly with a covering like vinyl or something. Maybe use pop studs to hold it in place. Just something neat and uniform that will hide the hole.I'm still thinking on this one.

While I had the folder out I cut out a bit of 0.7mm stainless sheet, curved the edges and hey presto - a heat shield for the exhaust silencer...

That's about where I'm at as of today. I've just started looking into fitting the fuel tank but I need to get some more hose. We also wheeled the green imp into the shed and this evening started making it smaller. Eventually it'll be so small it'll fit into the van and can go to the scrap steel man, less the roof and some tricky shaped sections I'm keeping just in case of whoopsies in the future. It's also handy to have another spare set of suspension arm, hubs and axles etc.

This shell really is too rotten to rescue considering the sensible values imps still seem to be at so I didn't cry too much at first cut. Bye bye little green Imp. You served me well and will not be forgotten...

 

[yoeddynz]

Chopping up the Imp shell took longer than expected. I'm pleasantly surprised at how solid they are for what is just a budget small car.  It was also even rustier than expected and I'm glad I was not tempted to try and make something of it.

I had to get this shot...

...and this shot.

All chopped up...

I rescued these bits. I have no idea where I'll stash them. Maybe hang the nose cone from high up on the workshop wall, led lights fitted into the headlamps.  I've now got a full spare set of suspension arms too. These could come in handy as bench top jigs if I look into mounting disc brakes on the back etc.

We took the remains to the scrap man the following day and he gave us $78 in return.  I had paid $200 for the complete Imp so it now owes me only $122.

Or I prefer to look back at the pies, cakes and coffee we both had in town after seeing Mr scrappy.

Back to the Impy project. I now really only had a bit of wiring to do plus some other little jobs. Wiring first. A bit of work in the 'frunk' to clean up the fuel pump wire routing..

Drained the last of the coolant out while I was there.. glad for the handy drain plug I had added when building the radiator in.

Work where the car needed to be on the hoist was over with but before I lowered the car onto its wheels I grabbed these shots which I really like..

Onto its wheels and rolled away for the first time since fitting the flat six. Wow. Pretty neat occasion in itself. Happy to see it still sat at the same height. Looking forward to weighing it in the future and seeing how much lard/muscle/festive season insulation its put on. I was now able to climb in and out of the doors easily and sort out the final wiring.

Stuff to be done was running the power and ignition wires to the ecu, water pump wires and some sensor wires forward then make it look all serviceable and neat enough. I had to extend the water pump temp sensor wire so the controller could be mounted in a sensible place. Take note of this last bit as I'll be coming back to it...

With the wiring now sorted I could move onto finishing of some other loose ends so to speak. But first I had to start the engine up in the car and check it worked.  Which it did after I swapped the two fuel lines in the frunk about so the feed did actually feed the correct line etc - only discovered when I was under the car with a container to clear the lines out of any debris and it came out the other pipe. Whoops.

So yeah. The engine just started up with no fuss on first turn of the key. Simples. Sounded great. The was no water in the system so I just ran it for 30 seconds, gave it a rev and let out a little giggle.

I then painted the parcel shelf cover thing that I'd made in the last update...

While that was drying I made a little lever for the exhaust valves. I started with an old pulley that I'd originally made for my V6 Viva..

Ran a long length of bicycle brake cable through from the engine bay into the interior via the routing that one of the original Imp heater hoses took.  Connected the dots with a tandem brake cable inner..

Out with the rivnut tool and put a couple into the inner sill.

Lever mounted...

Sound levels turned up to 11, small kids scarper, nuns faint and dogs howl in the distance* when lever is turned as such.

*Hopefully.

Next up was filling the cooling system with water.

Not coolant.

I've learned from that mistake and I'm sure I'll be having to remedy some sort of issue which might involve emptying it out again. Turned the electric pump controller on and noticed it telling me the water was a balmy 54 degrees.  It definitely wasn't. Its winter here (apparently) and the water was 15 degrees according to my volt meter temp probe.  That bloody sensor wire!  When I lengthened it by about 800mm I used 12/0.15mm gauge wire. The original sensor wires were 17/0.15. I didn't think 5 strands @ 0.15mm were going to make enough difference to change the reading but how I was wrong.

So this was where I was working early evening yesterday...

I rummaged through my extensive supply of cables, picked out a few that might be ideal and started with some beefier speaker cable that had many more strands. I didn't count them as tiny. I just connected it up and tried it out. Bang on!   Both meters read exactly the same. I tidied it all up and we started the engine. Ran it up to temp which took ages because by now it was only about 11 degrees. No leaks and the pump seemed to bleed of air easily. Hannah took a vid of me giving it a cheeky rev. Such fun. You'll see that in the next vid. Interestingly and annoying is that the exhaust valves don't seem to do anything to the engine note at idle. Maybe they will make a difference when asking more of the exhaust?

It was by then too late to go out for a hoon. I still had to fit the belts, all of the seats, the nice blue parcel shelf engine hole cover  and also the actual engine bay lid. So I spent the evening finishing these tasks off. I'd love to have driven it because it was a clear, albeit cool, day. Lots of heavy rain expected the following few days. Oh well.  It was great to see the interior back in. Although the recaros don't match the interior colours I just love seeing them. I like this pic. Old and new. 'West German' seats, old imp interior, sneaky megasquirt and usb cable.

So this morning it was finally time for the big occasion.  There were so many things to go wrong, not work, be noisy etc.  We just popped a tool box in the front, plugged the laptop in and went for a drive...

Wow. It works! The clutch pickup point was spot on, gear change seems fine in a mechanical way. The gearbox was quiet. No whines.  The engine was completely out of tune and we couldn't really tune it properly on this short drive. We did about 12km but a combination of the very cold morning and a very efficient cooling system meant the engine wouldn't get above about 80 when on the move so for much of the drive it was still on warmup enrichment. I now realise that I should have upped the temp setting on the pump controller. I think the default is 85 degrees so it pretty much had the pump running full time. I want this engine to be running at 95 degrees C.  But hey - great to know the cooling system works well at cooling.

The exhaust is more than loud enough. There's no insulation above the engine cover so that will refine the interior when cruising and how cool it is to pop into a 5th gear!!! Again, due to lack of tune I couldn't really note what the gearing is like. I never really gave it the full welly because my dash rev counter wasn't working (I have a sneaky suspicion I plugged in the wrong signal wire that currently goes no where) 

I just drove the car and enjoyed the fact that this moment was finally happening. Hell - it was March 4 years ago that this engine first arrived on a pallet.

The things that were not so good..

The clutch bite point got lower and lower until it was tricky to get into gear. Either failing slave or master cylinder. I suspect (and hope) its the MC.

Its a bit fumy. Granted it was running pretty rich and the rear cover I've made is not sealed properly.

The gear lever knob moves back and forth with the engine/transmission movement. Not annoying and only noticeable if you keep your hand on the knob (chuckle) while accelerating. I had figured it would because its a very slop free mechanical connection. Maybe stiffer engine/box mounts might help but then I could expect to have more noise in the cabin.

The weather was a bit shit so we went home, had coffee and cake and I looked over the car.

It leaks oil. Typical. It was weeping/dripping from the point between the heads and case sides where the oil drains back into the sump then running back with the airstream and spitting onto the muffler. So there's some of the fumes then. Only happens when the engine is running but its enough to be an issue I want to sort out asap.

The leaks are here. This side where it leaks straight onto the cooling pipe and runs back...

The other side.. Nothing to leak onto but its still getting flicked back by the airstream onto the muffler...

Here's a head gasket.

You can spot the drain hole. Its only pinched up at the bottom by one 6mm bolt. If I knew then what I know now I'd have added a thin smear of threebond sealant on each side of the loop to be sure.  Oh well.

The mess it made on the muffler.

So that's where I'm at. We checked the clutch. It works fine on the hoist. Bite point still at halfway?. No obvious leaks or traces of fluid from a leaking slave cylinder. Fluid level was fine.  I'll check the m/c tomorrow.  We bled the system again just to be sure. Only other thing I could suspect would be a dragging spigot bearing but I cant imagine that being the case. Its a new sealed bearing.

As for the oil leaks. I'm going to try removing the lower water pipe in situ and get enough room to apply marine sikaflex 291 or similar. Its under no pressure so hopefully should seal ok so long as I get it super clean beforehand.

We will test it all again, leaks or no leaks, when the rain stops (rain warning for our district this weekend) but for now I am simply chillin' and relaxin' and celebrating the first drive in a flat six powered imp that sounds pretty glorious.

[yoeddynz]

After settling down from all the excitement I had a little break from the car for a day or two while I got some other stuff done. Plus it was raining cats and frogs outside. We ended up getting 160mm (6.2" for those imperial folk)  of rain in two days.

I made a rough plan on what I'd do next to iron out some of the issues. The leaks and clutch were the most urgent. 

We bled the clutch again. It seemed fine in use on the hoist with Hannah in the car working the pedal in and out while I turned the rear wheels. Bite point still roughly in the middle of travel. But I'm still going to look at the master cylinder because from a peek under the dash it doesn't look that flash...

It has been playing up (bite point getting low) with the Datsun engine and it's not been touched in the 5 years since first getting this imp on the road.

There's a seal kit waiting for me in town and I'll see how good it comes up.

The leaks next.  I had a suspicion that the little vent hole in the filler tube was letting oil squirt out as the oil splashed up the tube. I wanted to work out where the majority of oil was coming from before taking the next steps.

Plus I wanted to drive the car some more before mucking about taking things apart.

So I folded up this oil shield with a folded edge that hopefully catches the oil...

'The oil shield 2000' bolted up below the cam belt cover...

Now I can go for another hoon.

But I need to easily spot my revs (because until tuned I'm not going to blindly go bouncing it off the limiter).

My rev counter wasn't working off the signal from the coil pack. I'm not sure what kind of signal that puts out or if indeed its working properly at all.  So I swapped the signal wire over to the one from the megasquirt. Still nothing though. The rev counter, being an old cheap thing ($7 from the swap meet) needs a high voltage spike like it gets from the negative terminal of the ignition coil.

Enter stage left a spare relay. I took it apart, removed switch plate leaving just a little coil...

Made this little harness..

Ignition voltage flows through the relay coil to the ecu tach signal wire.  The rev counter tach signal wire is connected to the ecu side of the coil.  Each time the current is switched off by the ecu it creates a voltage spike to the old rev counter so emulating an old ignition setup.

This was a fun little job made nicer by having 'driven' the imp out into the sunshine. The ground had already dried nicely after the rainy weekend, the sun was hot and it was nice to be working in natural light.

Fitted the little 'Ignition spike generator 2000' in place and now I have a working rev counter...

I'd also folded up a bit of alloy, stuck some double sided tape on and remounted the water pump controller angled upwards so I could read the bloody thing ^

Note how generally untidy that lot is. I really want to remove the lot, put it in a bin and rebuild my own dash and instruments. That is future Alex's job though. Time for a second drive.

Boy its quick! I let it get up to about as hot as it could and did a spot of auto tuning. The tune was improving all the time as I tried to drive in as many areas on the fuel map as I could. I still didn't want to drive for too long because I was aware that the oil leaks were no doubt covering the whole back of the car with a fine mist of muck but I gave the throttle a bit more jandal (actually bare foot) and took it up to 5k. A mix of genuine surprise, shock from going that quick in the imp and mechanical sympathy held me back from going any higher.

Its wicked!

It really snarls.

Very much looking forward to getting better footage including some drive by clips so I can give a you all a better idea. Its much quicker than I was expecting from what should be a stock 100bhp (but could well be less or maybe a little more) and I figure its the 115lbft torque that's making it feel so punchy and fun.

Once back home and into the workshop it was up into the air to see where the oil splatter was at its worst. Sure enough most of it was around the filler cap area. That vent hole. Luckily its very easy to undo one screw and remove the filler neck. See the little hole here, above the screw hole...

I filled it in with some quiksteel epoxy putty and refitted it with a smear of sealant around the joint and screw head just to be sure.

I also made this.

Its a cablestay 2000. It stops the O2 cable from going for a sneaky wander across the top of the oil filter pedestal and straying too close to the exhaust headers...

One other issue I have been thinking about (too much) is the coolant system not getting hot enough. From extensive sofa residing google searches there's a few Davies Craig pump/controller combo owners in colder climates who can't get their cars up to temp, or at least not very quickly. Interestingly it was often Triumph car owners. Stags and Dolomites etc. 

The controller chip runs the pump through 3 main settings.

At warm up runs the pump for  10secs on, 30 off until it reaches 20 degrees below the user defined target temp.

Then it goes to 10 on, 10 off.

At 5 degrees before target temp it has a lineal ramp up to pump on full time.

Ideally it should be able to pump slower or for less time when its cold outside because on these colder days (circa 10-15 degrees) takes quite a long time to get up to even 80 degrees if the target temp is say 90-95.  I was getting a bit too thinky about all this, doing lots of frantic googling and getting ready to type a strongly worded email to Davies Craig.

I was also prepping to build a thermostat housing, just as some had on various threads I'd read.   I even bought some alloy. I wasn't keen on this happening though. Adding restriction is one of the main reasons for premature pump failure (according to other threads..) plus it was going to be adding more ugly things to go wrong.

But common sense prevailed...

Goldwing engines seem to sit at around 87-90 degrees when cruising right and while they can happily handle more heat I have no need to chase it. 

Its pretty cold here. About as cold as I'd normally expect to see when I might be out in the car. Summer is bloody hot. Be happy it stays cool easily.

Finally.. up the target temp a few degrees higher so the controller sits in the lowest flow rate possible. Rest easy me.

So we went for another drive this evening. A good strop. Up some hills. Did more tuning. Tried to see as much of the fuel map as we could and let the program do its thing. It was getting better all the time although the fuelling will only end up as efficient as what I have set as targets. If I have that wrong then it'll always be wrong. Lots of driving to do so I can tune areas more by the seat of my pants and what feels right.

But it was already much better and I was getting more confident and it was fun. Not so much for Hannah who was trying to hold onto the door and the laptop at the same time though.

Clutch seems to be holding ok and the bite point seems ok but I'm still replacing that seal.

At one point we heard a sound and saw something bouncing on the road in the cars wake. I stopped and checked the engine bay. Nothing amiss. Then I looked at the oil level (that little light under the cap never gets boring..) and the level was down. Hmmm. No signs of oil mess on the rear though. Maybe its just the oil level when the car is idling and hot...

We drive up the road again and spot that the thing I must have clipped with my wheels was a bit of roadside marker.

Go home now. Play is over. Its getting dark. Onto the hoist...

No signs of mess at all on the back like the last two drives. Have a look under the car..

Clean as. The slightest hint of oil on one rear sump bolt. But no drips. Result !!! It must have been that vent hole.

The low oil level? I checked it with the car on the ground again hoping it had risen as the oil drained back but no. Then I released the cap and the oil level in the  filler tube rose. Ha. It's that well sealed. But really it needs a vent so there's no pressure changes. I'll have to look into it because I don't want oil pissing either. Going to be tricky with such a low cap.

Other things I have done is go on more romantic dates with Hannah to the wreckers where we looked for bits. I got these to try out for the basis of my custom instruments. If I can get the speedo head working fine with my Toyota speed sensor then I'll strip it further.

 

 

[yoeddynz]

Picked up the clutch MC seal kit from town while there for the weekly shop. Got home, removed the fuel tank to gain access to the pedal box, removed the cylinder and stripped it.  Like I said , its been 5 years since I last had it apart.

I'd like to blame this time span for forgetting what the main seal looks like.

Or I could just blame my own stupidity for not looking up Imp seal kits before ordering what I thought was the right kit in because what I'd bought doesn't look much like what I needed.

Oh well. The seal doesn't look too bad, nor the bore too worn. The seal could have sharper edges for sure but it would just have to do because I wanted to go out for a good drive the following day. I'll sort out replacements for the future.

I reassembled it all and Hannah helped me bleed the system, again.

Seems ok so we got all the blankets that used to be in the car and covered the rear parcel shelf in a bid to quieten down the engine thrum.

This morning dawned a bit chilly with high cloud. Since it was about 6 degrees I used that as a chance to further tune the cold start.  Once warmed up I tried sorting out the hot start. It would always start but then die unless I held the throttle open and let it settle to idle. If I didn't hold the revs up it would stumble into in the low revs/high load area on the main fuel map and I thought that was too rich. So I leaned those bins out. Got sick of mucking about and we went for a drive. By the time we got near our morning coffee destination the sun was out and it was lovely!

We had a date to meet up with another oldschooler and there he was, waiting with his small rear engined noisy toy by the beach. I took some pics. Its one of the few cars that makes the imp look large...

Dylan went for a hoon in my imp and then I in his x19. The various folk about the carpark with their dogs and kids must have had a giggle. We both must have looked clown like emerging from these tiny low cars. I'm 6'2" and Dylan is even taller.  It was great to try out a x19 with a proper amount of power and it sounds great.  I'm looking forward to when my Imp is properly sorted so we can do some spirited cross country drives. My throttle tip in from idle was a bit sensitive and inclined to bog down making it tricky to get used to.

After a good coffee we parted ways and Hannah and I went home. On the motorway (Tasman 'motorway' that is.. there's like 3 areas with decent passing lanes) I was able to see how it was at higher speeds. It cruises along effortlessly at 100kph pulling around 2900rpm. Luckily the 'its getting boring now' exhaust boom is not around that zone.  I'm going to have to do some work to the exhaust and try to tune out some of the drone. I have ideas already on how.

Before getting home Hannah took some driveby vids. Once home I threw them together and popped them up on the tube. It sounds great. This is the first time I have heard it properly as such.  Please do it justice and listen to the vid on a decent sound system because phones won't do the low notes any favours.

Once home I had a play with the off idle area of the tune.  I started by adding fuel back to the area I'd removed it this morning and this improved it muchly. I tweaked it, tested it, tweaked it until it was now much easier to open the throttle from idle without going lean and lurching.  Then the hot start issue. Turns out I just needed to add more seconds to the 'crank to run taper time' in idle control. 5 seconds wasn't enough. Just kept adding time until its started and settled gently down to idle. 

Those who have tuned their own efi projects will understand just how satisfying this shit is and also how frustrating it can be until you learn what needs to be done. So I ended the days tuning on a little high and decided to tinker no further so left it at that.  I put the imp on the hoist, up in the air and checked for leaks. But for a tiny weep from one bolt area there's nothing. In fact, touch wood, this is now the least leaky of all our vehicles! 

 

[yoeddynz]

Over a month has passed since the last update. That went quick! 

I've been busy on other jobs so the Imp had to get time where I could. The cooling system was what I wanted to sort out. I had emailed Davies Craig about their electric water pump controller. I explained the issue in detail and the friendly tech fella there ended up calling me a few days later. We chatted for 45mins and ran through the system. He'd actually taken the time to read the full build thread which he said he'd really enjoyed. This also meant he was well informed about my setup.

From the conversation I learned that I could have a more effective bleed system setup which will help not only filling the system up from dry but also possibly help the warm up. If it didn't warm up effectively enough after changing that then I could add a traditional wax type thermostat in.

I had already gone down the path of starting to make a remote thermostat housing before the phone call anyway so I continued with that first. We had popped to the wreckers and got a thermostat and its cover from a Nissan k11 (of course..).

I machined up a flange to take that and welded it onto a tube. Then stepped the tube down in size, added extra alloy I could drill and tap to suit the 3 temp sensors. In the end the whole thing was made from about 7 bits of alloy. Its not pretty but it fits in the same location as my original sensor pipe.

You can see the added bleed stub sticking out. This bleeds off air to the new expansion tank I was going to make. I have added the same size take off onto my original sensor pipe which I'll be using first - just in case I might not end up needing a thermostat.

Originally the sensor pipe had a larger feed pipe taking fluid from the expansion tank - which I was informed was the wrong location because the sensor pipe is on the pressure side of the pump, coming off the engine. Not the suction side that it should be feeding into.

Silly me.

So I now had to add a feed point somewhere into the system before the pump. Luckily there was just enough room to do so on the pipe just before the pump. I removed the pipe from the car and added this feed here...

I also removed the main front to back pipes that run under the floor. I was happy/relieved that they come out ok without having to take out the fuel tank. I wanted to drain the complete system of the old water/dirty coolant mix but these two pipes can't be drained properly and they hold quite a lot of fluid.

So I fixed this issue. Machined up some drain points and welded them at the lowest point..

Super easy to drain the lot out now without having to even touch a hose clip.

Now onto building a new expansion tank. I have been planning to do this for some time. The old one that came with the race car is steel, heavy, ugly and rusty. It also sits in the wrong spot and upsets my engine bay Feng Shui. It just had to go. This is also where some time got lost....

I started by machining up a filler neck to accept the smaller type of radiator cap.

Then some simple cad work...

Welded bits..

Cut, bent, folded, welded, machined and out popped this...

Wire brushed it...

Painted it in epoxy paint (and the thermostat housing too)

Bolted it in place...

Then chopped it up because I didn't like it...

Yep. Bit of time down the drain that. But I just wasn't happy with it. It was still too obvious, too sticky outy and upsetting the generally symmetrical engine bay. It was also going to make my planned bulkhead cover more awkward to make and fit neatly.  So back to the drawing board. I cut out the filler neck, machined it clean and started over. No pictures of it being built because I just cracked on and got it done. Finished result though..

You'll see how it fits soon.

Next job was to see if I could quieten down the exhaust boom. Those exhaust valves didn't seem to make much difference in sound and it was more than loud enough anyway. So they could get lost. I took the muffler off, such an easy quick job. Took it apart...

Removed the exhaust valves and made some extra baffles to hopefully knock a bit of sound off.  V shaped 'ceilings' in the first expansion chambers...

and extra baffles on the outlet chambers...

I also removed the crossover hole between the two halves. Simply not needed on a flat six and I suspect it was stopping the distinctive flat six sound at idle.

Bolted it all back together and got stuck into the next fun job.

Not an essential job at all. But one I wanted to do. I have never liked the ugly, non symmetrical covered up hole where the Datsun cylinder head used to pop up through the parcel shelf. I've wanted to hide it behind something nice. So I got a sheet of alloy from our rack and cut out a cover. Gave it a curve in the folder...

Had to recess it in the very centre right where the Plenum/spaceship resides. Not much luckily.

Cut some strips of 4mm alloy...

Gave them a 'brushed' look with my poor mans linisher...

I had been ringing around all the various upholsterers about my district and no one had any black leather in stock plus the prices they quoted were absurd. I had bought some black vinyl instead but wasn't really happy with the idea of something so flammable being above the engine.  Popping into Tasman canvas on our way home from town was just an idea at the very end of the day because I thought maybe a canvas could work. But they had some leather left over from a job and were happy to help out with some offcuts.

Leather carefully glued in place...

Then the alloy strips were carefully bolted in place. Before fitting the leather Hannah and I had deliberated over the positioning and spacing of these for some time. The idea is that I can remove them at a later date, cut them short so the middle has a gap in which I can fit a badge/logo of some sort.  This will then mean there's six strips, 3 each side, much like a flat six. 

Deciding on what to put in the centre is now the hard part.

So some pics of it all in place, along with the new expansion tank tucked away to the side...(the little bolts will be changed to dome heads when I next get some from the city)

I'm pretty happy with that. I might well change it out later on but for now its hiding the ugliness behind. The new tank is a huge improvement in looks and its tucked away neatly. The new bleed system is a massive improvement too. I filled the whole system up so quickly (9 litres in total ) and the air bled out really quickly this time.

We started the car up today. New exhaust is quieter but still a bit boomy at certain revs. Not a concern right now as its not a daily. Just a fun toy.

The cooling system heated up much quicker (A very cold clear 10 degree mid morning at the time of testing today)

(EFI tuning talk time. Carb folk look away)  I'm now going to spend some time really trying to fine tune the idle. Its idling happily at  a touch over 700 rpm but I think that's a little low. The hesitancy just off idle when for example you squeeze the throttle to pull away needs to be tuned out. I think I'll get it sorted on the VE table alone. Its not an acceleration enrichment issue. I want to get this area sorted so anyone can jump in and drive it about town slowly without any stumbling or hunting. Its still on open loop warm up idle control which I want to have dialled perfectly before I look at maybe going to closed loop.

[yoeddynz]

I've been chipping away at bits on this. First off was to sort out the idle tune (warning - more efi jargon coming up).

Since that day I started the engine for the very first time on the bench there have been a few settings changed that are not ideal. I'm not even sure why I changed them but I think it was when I was mucking about trying to sort out the hot start issue very early on. I think also when I changed the idle control valve I might have played with some settings.

So in order to start afresh so to speak I looked back through the restore points. These are saved every time the tuning program is used. I can go back through the files, look up a date and 'backdate' the whole tune or part of the tune. I went back to the default warm up curves that are loaded with the firmware, altered a few bits, turned the EGO correction back on (not sure why I had disabled that) and generally gave the settings a once over. I enabled 'incorporate AFR' and set up a suitable ignition based idle rpm timing curve - previously disabled.

I then rolled the imp out into the evening light...

Removed the engine access hatch from inside...

Then I wound out the idle air screw a half turn until the revs came up to around 800ish..

Later on after dinner I went back out and sat inside what was a very cosy, warm, slightly noisy tuning room and tweaked the hot idle until I was satisfied with the idle.

The following day we went for a good drive into town. Did a bit more road tuning but the temp was still not really getting high enough and would drop on downhills. I was going to have to fit a mechanical thermostat. Took the car to our local Repco branch and showed the crew in there. Lots of revving up of the engine took place

The fuel tank pump access lid was weeping through the 'fuel resistant' gasket card and apart from the fumes its not really the safest situation to have.

The clutch master cylinder was still leaking so that needed attention too.

Plus I wasn't happy with my fuel lines under the tank - a mix of copper pipe, different offcuts of hose and many hoseclips because it was all I had left the weekend of the first drive when all I wanted to do was drive the car.

So out with the fuel tank. I ordered a brand new master cylinder and a high flow 82 degree thermostat which arrived in the mail the following day.

Here's some pics of the 'frunk' with the fuel tank removed. Radiator shroud in place. It works really well at directing the hot air out and keeping the tank cool.

Removed..

Fiat/lada tandem master cylinder and brand new clutch master cylinder. Note my unsatisfactory fuel line routing..

I got a deal on a 5m roll of injection hose and re-did the lines, ending up with a handful of spare hoseclips in the process. Pic of work in progress..

As for the leaky fuel tank lid. I ordered some 70% nitrile rubber sheet. I'd rung up lots engineering supply places and various workshops locally hoping to find what I needed but no-one had anything to suit. So I bought some from a supplier in Christchurch and the postage cost the same as the bloody rubber! Our local barefoot postman was pissing himself when the square foot of rolled up rubber sheet that could have been posted in a small post bag  turned up in a huge box.  FFS.

Cut the rubber to suit including a new gasket to suit the sender unit..

The thermostat I'd bought was up next. I fitted it into the housing I had fabricated a few weeks ago. Hannah asked if I was going to check it for leaks before fitting but I was confident my welds were fine and it would be ok.

Nup. It leaked. I counted 4 pin holes..

So I welded them up and to be sure of sealing I painted the inside with epoxy paint before fitting it back into the car.

This morning I woke up and was now a half century old. Wow. Cool. I felt the same tbh but I'm always a bit happier on this day because Hannah usually makes me one of her amazing carrot cakes..

So after a very relaxed morning of cake and coffee I refitted the tank. Since the tank was bone dry we measured in the petrol because I have been wondering for some time about the accuracy of the fuel gauge. Turns out that its bang on. The little tank holds 27 litres when full and with 6.75 litres poured in it measured exactly 1/4.  It remained accurate at 1/2 and 3/4 full. Hannah duly jotted the findings down in the little imp book of notes ...

We then went for a birthday drive. The engine warmed up so much quicker and stayed warm. It was a very cold and wet day so I wasn't expecting it to get super hot. It sat around 85-90 degrees which I feel is fine in such weather. We did a good 50km route with a variety of hills, straights and twisty bits to extend the engine so allowing the autotune program to do its job more effectively. The tune was much improved with the idle now being very consistent. I still can't get over just how smooth this little engine is. It's amazing.

We noticed that at 6000 rpm when the engine hits the limiter the needle on my 2" rev counter ($7 second hand from a swap meet many moons ago) does a big kick-swing. It must be affected by the limiter?  I am looking forward to building the new instruments though. An accurate speedo that doesn't swing and a rev counter in line of sight will be a nice thing to have.

The gear shift seems to be lightening up in action and getting smoother. I think this is due to the shifter base and shaft guide bush bedding in. There's always been a metal on metal hard knock under full power shifts which I had discovered was one gearbox mount knocking the cross member. I'll insulate it with some rubber and down the line I want to look at stiffer mounts all round.

The handling seems fine. Definitely a bit more weight out back, how much I'll only know when I next weigh the car. I'd like to borrow some corner weight scales so I'll ask about my local race car mates. In such wet conditions like today I just drove it as one should drive any rear engined car. Get my entry speed sorted before the corner, don't lift off mid corner and then just power on out. It sounds fantastic and is very fun.

Speaking of noise. We are both already used to the drone which comes in at around 2200rpm. Its gone by say 2600-2800 and is worse when under load. So I select the right gear and most of the time its easily avoidable. Its more fun holding onto a lower gear anyway.

When the rain had eased I took some pics ..

Hannah is in charge of the laptop..

Got home, car still in one piece, oil and coolant still in their respective places. Tyres definitely in need of replacement though (but not until I sort the front camber out). Overall a good result and a nice way to spend a birthday afternoon.

To top it all off a friend of ours dropped around a home made sponge cake because I'd looked over her van for her earlier in the week. She told me the cake is very naughty... so this next half century is starting off with a few extra calories

[yoeddynz]

I have a confession to make. I feel dirty for what I have done and must come clean.

I have raised my car

  Hear me out though. I know its a terrible thing but my hand was forced and it had to be done.

So after my birthday cakes had been all eaten, mainly by me (little fatty), I decided I needed to look at the suspension. My front springs are essentially Rootes 'Monte Carlo' spec which means 195lb" and 9.5 inches long, or about an inch shorter, with one less coil than standard imp springs...

But because I'd modified the spring perch on my stock dampers to make the car even lower it meant the Monte springs were not captive at full droop without the aid of retaining straps. These are fine in use in the UK and quite a common fitment on lowered Imps but they wont pass the muster here in NZ for certification when that time comes. I also had a total lack of any height adjustment without resorting to various spacers beneath the springs etc.

So I started looking at various coilover kits made specifically for the Imp. There's at least three brands out there that do kits, all made in the UK and all quite expensive once freight is added into the equation. Luckily I ended up chatting to a fella called Frank in Australia who I've bought stuff from before. He imports and sells Gaz coilovers as well as loads of other Hillman based items. He had a near new front pair he was removing from one of his Imps and offered me a good deal on them. They are the 'short' dampers to suit lowered imps and he was including the appropriate 'super low Monte Carlo' springs.  These are 8.6 inchs long and needed if I wanted to keep my Imp sitting nice and low.

So while they were on the slow boat from Australia I started looking into the rear shocks. The stock Imp items were working ok but I knew that one was low on oil and not ideal in action. I was informed that Nissan Navara D21 front shocks were an almost straight swap so I got a shiny almost new pair from a ute at the local wreckers to try out. To my surprise they were actually considerably softer in damping than the Imp items, both in bump and rebound.

Still, I had them to try so I machined up some suitable spacers to suit and the smaller Imp bolts and the top bushes..

Bolted them in place and went for a drive. 

Nup. I don't like.  Too soft and a bit too wallowy. Passable for normal driving on smooth roads but start driving with a bit of enthusiasm and the back end starts getting a little bit flighty, especially in sharp compressions. I would have to sort something else out and started looking into ideas. Then the Gaz coilovers and super low springs turned up. Here are my standard Montes next to the super lows. The same coil count and rating but just set shorter.

I wanted to test them just to be sure so things got a bit scientific..

They were rated exactly as they said on the tin.  The Gaz dampers and superlow springs showed the overall length from bottom eye to the top of the spring to be very similar to my modified dampers and standard Monte springs. Things were looking promising for me to keep my Imp at the same height.

So I fitted them..

I then removed my retaining straps and the arms dropped further, so releasing my springs from captivity   I had to wind the collars up 15mm to hold the springs from rattling about. Oh well. I suspected I might end up in this situation. On the bright side it does mean the excessive negative camber has been removed and I also wont be smashing so many hedgehogs/other roadkill with my license plate.

I went to sleep and had nightmares about my new lofty height. This morning I revisited it and replaced the absurdly thick, what look to be just generic damper top mount rubbers with my old stock Imp items. This moved the shaft fixing up 5mm so allowing the collars to be lowered the same amount. So I now have a 10mm extra ride height with room for adjustment and completely captive springs.  The camber is about bang on for what is recommended on a road imp. I took it for a good drive to try them out but I'll talk more about that soon.

Moving back to the rear dampers. I removed the soft Navara items and looked at my leaky unit. The shaft has a small amount of light corrosion just below the bumpstop.  Although it was fine when I'd fitted the shocks, 13,000kms thereabouts of driving since has seen it lose fluid.

I had a plan. They are pretty common designed double walled units. There is a gap between the outer tube and the inner tube that the piston slides up and down. As the shaft enters the damper the oil height increases from displacement. This cavity was down on fluid.  I drilled a tiny hole near the top, through the outer skin and whilst extending the shaft out I added oil with a small syringe.  I then tapped the hole and fitted a small machine screw and O-ring. The shock works perfectly enough now, at least until I get some replacements.

Now it was time to look at the rear ride height. The new engine and gearbox is at a guess something like 20kg heavier than the Datsun setup. I'll have a better idea next time I weigh the car. Its enough that the car has sunk maybe 5 or 10mm. Not a lot but combined with the higher front it now had a distinctly nose up, bum down look that I'm not keen on. Plus I'd like the driveshafts to be a little straighter. They were heading slightly uphill to the hubs with the angle getting steeper as the rear squats under acceleration.

The rear springs are standard 1" lower, slightly stiffer Monte spec.

So I made some 15mm spacers. Probably only needed 10 but I can machine them down. It now sits as such. Bum slightly up. Half a tank of gas. Exactly no bags of cement thanks Barry.

Hannah measured both front and rear arch heights as I sat down into the car and shut the door. Interestingly, and I think quite a good thing, is that the car drops 10mm equally front and rear.

I'm going to try this new setup out before deciding if I skim my spacers down.

Another important issue I really wanted to sort out was the exhaust drone. Every time we would take the car for a drive the drone was overpowering. I wanted to believe that we'd get used to it or learn to drive around the drone zone of roughly 2300rpm but it was futile. It had to be addressed.

Mention of J pipes, resonator pipes or 1/4 wave resonator pipes or whatever name they might have was mooted by several people. Not just on for this car but also on other peoples threads and on the oldschool exhaust discussion thread. I read up about them and they sounded like an ideal potential solution but I really just didn't have any room to fit them between the exhaust box and the headers.

But how about inside the box?  Extend the inlet within, tee off from that to the outside and use an elbow to send pipes forwards. I looked through my collection of random stainless tube fittings..

Something like this?..

Hmmmm... it could work and was worth an investigation.

Car on the hoist and within 5 minutes the entire exhaust box was removed. V clamps are fantastic. I removed the gazillion 6mm bolts, broke the silicone seal and removed the lid. Some measurements were made and a holes were cut as neatly as I could with the plasma cutter.

I hole sawed some stainless tube that matched the inlet diameter..

Welded a slightly smaller 32mm pipe and fitted the tees into each end of the box.

Pulled out the heavy length of 50mm 304 stainless bar and cut off some discs

Those I machined up into stepped flanges. 4 holes drilled and tapped in them to suit and then welded onto the outlets on the box.

The J pipes had the other flanges welded on via the inside..

Above the new Tee pipes within the box end expansion chambers I added a shelf of stainless perforated sheet that bolts in place and then filled the void above with more packing. This was just another way I could absorb some sound..

Lid was siliconed back in place and bolted down. Now the J pipes. I fabricated those up with the bends and made them as long as I could. There are multiple websites with ample information on how to calculate the required length depending on engine rpm, frequency, cylinder count etc etc. But they are usually dealing with exhausts that have just one main exhaust pipe to J pipe off from. 

My setup is like two 3 cylinder engines really with their own separate exhausts. I wasn't sure which calcs to use. But pretend I have just one exhaust feeding off both banks I was looking at a J pipe length of circa 800mm. I figured I would halve that and my finished J pipes came out at just on 405mm with the ends almost meeting the rear arch inners. I figured I can always chop them down in length so better to start as long as I can.

I found some ideal stainless penny washers for the end caps..

J pipes installed...

They are a bit ugly though. Although I can't see them from within the engine bay they are easily visible outside and I don't like seeing them. I have also never really liked the way the box ends don't tie in with the back corners so I had an idea to try. I carefully made these stainless guards..

There were already some useful holes I had added to the valance lip for the Datsun exhaust..

Guards/ugly pipe hiders in place...

Time to try it out. I was pretty confident that there was going to be some amount of noise suppression but how much ? Upon start up we could both tell it was quieter. Took it for a drive to go pick up yet another customers rusty Hiace for work and yes - it was quieter!!! The drone was knocked right down. Its still there at certain loads but no where near as horrid.

Now as per the earlier mention of a drive to try out the new front shocks. Well it was also a good chance to try out the exhaust. This time I was sans Hannah. It meant I could thrash the car to my hearts content without Hannah having to cling on for dear life. There are no grab handles in the car and the Recaros only hold you so much. I took the laptop though and used it as a chance to let the autotune see some of the more extreme areas of the fuel map.

30kms of twisty hillclimbs local to us and a good solid use of the throttle travel. Damn its fun. The exhaust is much better drone wise but I almost want a little more sound. From inside the car its still more straight six than flat six. I'd like more of the guttural, raspy Porsche flat six sound.  My exhaust/engine sounds smoother.  A bit of this could be because its water cooled and the Porsche 911s I like most are aircooled (and usually twice the capacity...) They are almost clattery at idle, slightly hollow.  I do some have other ideas floating in my head about future exhaust designs. I know these engines can sound more 'Porschey' but I don't have as much room to play with as the bikes I have been viewing.

 But wow- this engine is a little gem. I'm tending to keep it in gear for much longer between corners because its so smooth at high revs whether I'm on or off the throttle. It'll be much better when I build my new dash and have a rev counter right in front, that's for sure.

The gear change is getting better and better with use as the shaft bushs loosen up a bit. I have ideas for improvements too but no rush. Its a delight to drop from 3rd to 2nd, a gear change that can make or break the fun to be had in a car driven hard on hills I feel. 

The program managed a good amount of changes to the fuel table and its pretty good now. Start up hot or cold is great. Just a few bits to smooth out.

I'm going to tweak the throttle plate stop screw and idle bleed appropriately. I think the throttle disc is a bit sticky when closed which doesn't help for light throttle action when trying to move off slowly.

The rear navara shocks, as noted previously were not helping. Looking forward to the next drive now I have originals back in, complete with all their oil.

The front shocks are actually about the same as what I had originally. I have set the damping to what I feel is about the same as the originals. It really doesn't require much damping in the front (unless some internet Barry has finally managed to persuade me that 3 sacks of concrete in the front really is the way to set up rear engined cars)

I am going to dig out the go pro, hope the batteries are not dead and try to get some better camera angles along with better exhaust sound representation. I really want to hear what its like from outside with the new exhaust and better tune.

[yoeddynz]

After my last long wall of text I'll try to keep my updates more frequent and smaller.

The throttle was a bit sticky and made gentle opening awkward. Parked the imp outside in the sunshine..

Removed the access cover..

Adjusted the throttle stop screw about a half turn in. Just enough to stop the throttle plate from sticking. You can see it here with a mirror...

Then wound the idle bleed screw in and touched up the tune around the idle area on laptop from the comfort of the rear seat..

It's now much better in action and way easier to drive off.

Although I'm happily getting the last bit of wear out of the old tyres and they always feel super stable and grippy when getting low, like a semi slick, they most likely wont pass another wof test.  They have always worn on the outside which I found odd considering the amount of negative camber. I have always swapped them back to front regularly but they still wore as such. I thought I best check the toe angle. I'd previously done it with string. Not the best way and quite a faff. So I made these measuring jigs up..

They bolt in place like so...

Making it much easier to check the toe angle very accurately..

Turns out I had set it pretty close. It was a little bit too much toe in so I adjusted it out to suit the specs and I'm happy enough now to get some new tyres soon.

Another small job I should have done years ago was to make some form of face level ventilation. My imp gets quite fumy if I open a window. I had asked on the facebook Imp owners group and it looks like its an imp thing that most folks cars suffer with. You have to hermetically seal the back end up of every little hole and gap to try avoid it but its tricky and my imp is possibly worse now with the centre exit exhaust outlets.

I just had to do something about it. I got this lot..

Cut a hole here in the plastic ventilation pipe the comes from the fan/pickup and heads to the heaterbox..

Pushed some alloy tube wrapped in gator tape into hole...

and popped the flexi alloy ducting in place...

I'll look into teeing the ducting off and run some to the passenger side as well. I need some neat little eyeball vents which I'll then fit into my new dash layout I have planned. But even this alone is a game changer. Even just driving up our driveway I could feel the flow of fresh air. Sooooooooooooooo much better. Wish I did this years ago!

Final bit for this blurb.  From the very first time I started the engine on the bench there has been a little random whistle. It didn't bother me at the time because I was just so happy the engine ran tbh.  But now its annoying me. Its not there at idle. Only when you open the throttle a bit from idle will you get a little squeak or if driving and it goes under a moderate load it can be quite loud.

Off with the access hatch again and with Hannah driving the car I tried to pin point where it was coming from...

Once home I continued the search, checked all the bolts, used bluetack to seal any suspicious gaps but no luck.  I've not nailed the spot but I think its around the plenum chamber or possibly something funny in the throttle body.  I got annoyed, gave up and we just went for another hoon to the beach for walk.

[yoeddynz]

Bloody hell time flies.  I'd better do an update.

That noise. I took the throttle body off again and taped up the various superfluous holes..

Went for a drive and the sound was almost completely gone. Just a hint at certain load points under very light throttle openings. So it was indeed created by air passing over the holes   - much like blowing across the top of a beer bottle.

Took it off again and filled the holes with JB weld epoxy..

I was now left with one remaining outlet that feeds air from the IACV into the throttle body.  This one is the cause of the occasional 'hoot' sound at low throttle openings, higher load.  Possibly the sharp edges could be transitioned out to curves which might help.

Its not enough to bother me though, especially as I now know what's making the sound. Just happy I don't have a vacuum leak.

Onto more fun jobs. The custom dash instrument cluster I want to make. Ages ago I'd got these instruments from a V6 engined Mitsi Pajero.  Electronic speedo head, with analogue odometer.  Very similar to the Toyota items of the mid to late 90s that I had used in my Viva V6.

I took them out...

Carefully popped the needles off using the two teaspoon method...

Knocked the internals down in size including removal of trip meter part..

Machined up some barrels from alloy to suit ...

..as well as some rings for spacing the gauge faces away from the acrylic fronts I'd cut out.

The needles were cut shoorter and the gauge faces cut down in diameter. Once tested and calibrated I'll make now faces with a more suitable looking classic font and style. I assembled them and stuck them onto a makeshift shelf on the dash for testing...

I then machined up an adaptor with the required m20 thread to suit the Subaru transmission...

Screws in here...

So a Toyota electronic (hall) speedo sensor can screw on top..

Went for a drive. The Rev counter works fine straight off and matches the rev counter readout on the tuning program.

The speedo reading is much closer than I was expecting considering I don't know what the gearing is on the transmission speedo output. The speedo reads about 10 percent out but does progressively go further awry as it gets closer to 100kph. When we next have a chance on a long smooth road my intentions will be to mark the speedo face using a GPS speedo as a guide for accurate speed (the Imps original strip speedo is terrible, wobbly and not accurate at all)

But none of this will happen for a little while because the clutch slave cylinder I thought I'd repaired decided to give up and make a puddle at the local fruit stall yard. We had been in town shopping and I could feel the bite point getting lower until the gears started getting very hard to select. Luckily where it finally gave up was only a few kms from home. I started the car in gear and managed to get home.  This then happened that evening...

So it was time to swap back in the Datsun engine for a short while. I have clocked up 680kms on the flat six so its probably a good time to pop the sump off, check the oil pump chains have settled in nicely etc. There's a couple of spots between seams that weep oil so I'll clean them up and re-seal. It actually barely leaves a drip though and the transmission  is completely leak free. 

So the Honda is now out and sitting on the engine wheely stand 2000 TM.  I made notes of all the various stages of removal, accounting for time spent and detailing anything that could be improved or tidied up.  I'll re-write the notes in order so avoiding needless hoist ups and downs just to undo one bolt etc etc.

As it was it took just 2 hours to remove the whole Honda engine/transmission/exhaust/gearstick/cooling bits.

I then had to adapt a few bits for easier swaps such as wiring up the Datsun loom (all 5 wires..) to suit the plug that also serves the Hondas temp/oilsensor and alternator etc. The wiring is now plug and play.   The axles also have to be swapped which is easy.

Before I plonked the Datsun back in place I really wanted to weigh it. I popped over to the farm across the road and nabbed our engine hoist back from their shed.

Removed the Imp transmission and then carefully lowered the engine onto the scales...

105kg. You chunky little monkey. Granted that is with everything in place inc clutch and exhaust headers.  Google reckons a bare A12 engine is circa 80kgs but I was never sure. Now I know exactly what it weighs. I weighed the Datsun cross member, starter motor, exhaust box and even the stock gear shifter arrangement. Anything that was different to the Honda setup. I also weighed the stock Imp transmission.

I noted all the weights down in my Imp notebook and consulted the weights I'd put down for the Honda engine and scooby box.

The Datsun engine and imp box setup inc its specific driveshafts, exhaust system and gearshift setup comes in at 156kg

The Honda and scooby box with its modified CV driveshafts, exhaust and modified gearshift tips the scales at 170kg

I was quite pleasantly surprised at this and it does tie in well with the weight I'd got when I recently had weighed the car at the local weigh station where it was about 40kg more than when I first got the imp on the road over 5 years ago.  Allowing for errors/weighbridge accuracy and the heavier Recaro seats I have added it looks pretty legit.

Happy with that I plonked the Datsun back in place, a process that went smoothly. I ran the low pressure carb fuel pump up front into the efi return line to the carb. My original Datsun coolant hoses still worked perfectly with the stainless pipes exiting the rear bulkhead that I'd modified to suit the Hondas EWP setup.

Swap a couple of wires on the fuse box, remove the efi fuses and turned the key. The Datsun started first turn of the key and settled down to a smooth idle. It actually sounded really neat.

I checked for leaks, refitted the engine cover on the rear parcel shelf and took it for a hoon.

God it feels slow and its so quiet. But its bloody lovely though. The gearshift is so sweet. Lighter than the Scooby box (although I have some ideas on how to improve its action)

So that's that.  Back into its little garage for now. I need to get some new tyres and then get a fresh warrant of fitness sticker.  I'd forgotten to mention earlier that I had taken it out to show the local retired certifier who is leaving his day job and will be getting back in certifications. He loves it and thinks its a very neat transplant.  I've run through a few bits that I know I have to add or change to pass the cert and hopefully some time next year it'll be first on his list. Fingers crossed.

Good little Dastun...

Back into its home..

 

[yoeddynz]

So I needed some new tyres. I did some research, rang around local places and found a good deal. I hoisted the Imp up,  removed the wheels and spent some time removing the old stick on lead weights. I then gave them a quick polish..

Took the wheels into the big smoke later that day and left them at the tyre shop while we went off to do very important city things that city folk do, like sitting in posh cafes eating yummy steak and cheese pies, talk about the stock exchange and shopping for outdoor furniture.

Later on we picked up the wheels and left the big city behind returning back to the quiet life.

Considering this is practically a hypercar there was no expense spared when it came to selecting tyres...

Fitted the wheels and out into the sun for a photo..

I took it for a hoon and other than the usual expected bit of 'brand new tyre wandering' I've always experienced they seem fine. Nice and quiet. They'll get better once scuffed off.

My old wof test fella that I have used for years has retired. I needed to find another 'sympathetic to old cars garage' so I drove it out to a place up one of the local valleys to a mechanic I'd got some advice from about Subaru transmissions. He really likes Imps, loves Datsuns and thinks the Datsun swap is great.

Perfect!

Booked it in for a wof test

Today I drove out there again. Its a great place. Loads of old cars in the fields surrounding the place and he has his old Hillman Hunter parked up next to the workshop. Tractors being worked on and lots to look at..

The car sailed through the test with the only issue being that it really needs rear reflectors to be fitted. My tail lights don't have any reflectors built in but its never been flagged before.  He had some small ones in stock to show me what would be suitable so I picked some up on the way home and fitted them.

Made some little brackets for below the bumper mounts..

Fitted in place. They don't look too bad but I am hoping there might be some alternative Lucas rear light that has reflectors built in.

Imp is now all legal again and ready for summer..

The tyres were already feeling way better too after having really scuffed off the silicone releasing agent or whatever it is?