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HKM400's 1969 Lotus 7 Series 3


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Decided to do some more to this today being that the other alternative was more study...

Went and bought myself some foam, vinyl and contact adhesive and upholstered the dash...




Cut the holes out




Test fit





Apologies for the less than shite pictures.

Pretty happy with how it turned out though


Discussion if you wish





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  • 8 months later...
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It's been a looooong time.

But I have actually made much progress no laziness here...


Car has now been properly tuned and has been driven several successful times- have switched back from electronic ignition to a lucas dizzy as the electronic kit I bought was a bit of a let down.

I am starting to sort out the finishing touches- have got an aeroscreen for it many reasons for this including the fact that I don't want to phaff around with wiper motors + unlikely to be actively pursue driving in the rain, interior is underway also. Trying to get it looking as tidy as possible before the warrant finally happens.


Drives nice, pulls away in 4th with minimal encouragement on the throttle. 


No recent photos but will suss that for the next post. 



One other thing.... haven't sorted a bonnet yet- will need to be the last thing made and there will need to be a hole in it as the manifold is on an angle.

Legalities of getting a WOF with no bonnet in the meantime? Guess i'm following the hot rod scene where t buckets often don't run a bonnet at all. Should say i'm not running a mechanical fan, have an electric shrouded one, nothing else protrudes to the point where a pedestrian would be impaled.


In saying that... if you found yourself in a position to be hit by this I would recommend a big jump....


Discussion and thoughts?







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  • 2 weeks later...

Made more progress last weekend, sorted the seat back ply, also fitted my aeroscreen which was easier than anticipated








The view from the business end




Actually sits higher than expected too, so should do a half decent job of diverting the bees and other various insect life vaguely away from my face.


Getting closer....


Excited for seats. Then it'll look proper car like.




Discussion if you wish,



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  • 2 weeks later...

Good eve,


Got part of the interior sorted this week. Very pleased indeed. 






Still have to get the tunnel done but that needs to happen at the upholstery shop. Lucky it's just down the road, and in the same complex there is a mechanic and wof garage who is going to take a look over it and point out anything that needs more attention before I finally send it for the ultimate test.


Also coiled up some cable to wire the steering wheel switches into the loom. 




Also got some JB weld today so can bog up the pinholes in my diff case because I am an impatient bastard and don't want to take it apart again for awhile. I just want to drive itttttt.


Discussion if desired.






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  • 3 weeks later...


So last weekend I was meant to attend Hanmer. Several reasons prevented me from doing so. Which was not mad.


However... on Sunday I decided to go for a small hoon in this. And I can confirm it is awesome.




Also mounted my extinguisher here because there is minimal space inside. Mostly reserved for human body parts.


The line up




Truck is hiding behind the tree so didn't make the photo. Sorry truck.


Funny for a tiny little car it looks bigger than the MG in this photo.


Also have some gopro footage of the drive. Which I'm not sad to say is too big to put on here- mostly because I was making stupid excitement noises most of the time.


Discussion if desired




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  • 1 month later...

Seeing as the weather is rubbish, and I have the convenience of a dry garage to work in, I did some more on this today...


Due to fitment issues the Pricol Mechanical Gauge I had for the car wasn't going to work- couldn't get a cable in there that would maintain a progressive bend so the cable could spin properly... as such I've got a new VDO Electronic Gauge and Hall Effect Sensor. This needs a rotating surface for the sensor to point at- I've just the bolts on the drive shaft... So hopefully the signal is strong enough.


Made a little bracket like




And then added the sensor...




Bolted my bracket up and aligned the sensor with the bolts... Apologies for shite photo- shiny surfaces and flash don't mix




Wired it all up and cable tied the sensor wire down so it doesn't get munched on




Which then resulted in this happening




Which pleased me. However the next step is to calibrate, which requires driving it 1 measured km, so that'll have to wait for another day when liquids aren't falling from the sky. 


Should also say I'm probably going to sell the Pricol gauge- never been used still in the original box. If anyone is keen let me know, will also list on the for sale section.


Should my wiring actually work for the sensor (Sceptical at best) the last thing this needs for WOF is a brake light switch- which needs to be a mechanical pressure style one in the lines- so I will have to pull a hard line out and go visit someone with a flaring tool and buy a switch...


Getting closer...





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Spurred on by the medium success of yesterday, I came home after work and did more things.




Needed to get one of these off so the mechanical brake switch can be added in- because my car is too small and I'm an idiot and installed the pedals without adding the switch when the side panel was off. This is also known as laziness. 


So decided on the right hand one as it's the easiest to access.

Needed to take the reservoir off because I couldn't get my spanner in to undo the bolts.




Which is when I decided to make a mess




But it was easy to take off then. I then cleaned up my mess because brake fluid is not very nice.




Result. One line ready to get chopped.


You may also notice my socks on the engine.

Not much of a fan of these.

Tried to get some proper weber mesh filters but they won't fit as the tubes are full radius.

Anyone get around this other ways? Or just make my own?


Off to visit Safe R tomorrow for the switch install.


Discuss if desired.






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  • 1 month later...
  • 1 month later...
  • 2 weeks later...

Been enjoying having this on the road, have taken it to diamond harbour and other various destinations- and to work on appropriate days (ie when it isn't raining and there is no chance of it raining). It's running really well. Some may have noticed my gearbox related ramblings which turned out to be the tacho reading high- and me feeling like an arse. This issue is now remedied with a diode in the negative line to the coil. Now reads as it should.

Have had an issue with the diff leaking- needs a pinion seal which I got from Enford during the week- I think using it over the last week or so has rooted the seal more so, it now drips a bit more than before.

There were also some pinholes in the rear case so I figured shit weather means an ideal time to change it. Took the diff out Friday and ground back to find my holes


Of which there are several. 

Also decided to check the bearings while it was out- they're fucked. Pitted and not good. The seals are also leaking through the backplate, which is very shit because it's got on the near new pads... I'm guessing there is no fix but to replace them? They weren't super wet but oil+brakes seems less than ideal

Will get a wheel bearing kit from Enford this week, will need to get the old ones ripped out and new ones pressed in. Hopefully that will solve my leaking issues and I will be able to stop very quickly.  



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  • 5 weeks later...

Many things have occurred.

I got new bearings and seals pressed in- which solved the leaking issue into the brakes.

I also had a new pinion seal put in- as it leaked... which is where I believe the new issues have arisen from.

Put it all back together one evening last week- but the diff is now extremely noisy on the overrun- which suggests that the nut on the pinion is not tight enough? (Based on reliable internet searching...) This puzzles me though as the mechanic that did it clearly marked the nut, and accounted for the number of threads and their location in relation to the nut- it is also the reason I enlisted a professional, as I have a feeling I was going to stuff it up. 


The noise hurts my feelings. 

Also on one of my recent test drives one of the headlight brackets snapped- which then meant the clamshell slumped down- so I'm going to beef up my mounts for the actual clams so there isn't as much strain on the headlight brackets. 



It looks so cool without front guards. 

I would take it for a sneaky open wheel drive if the diff didn't cause me so much concern. 

Any advise on my noisy diff would be appreciated. 



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  • 3 months later...

Have put around 800k's on this so far, nothing has really gone wrong apart from the clam shell bracket breaking, the diff continuing to whine, and being caught out in the rain on 3 occasions. 

Looking to change to cycle guards- will have to figure a plan out for that. 

Also looking into changing the diff- might go for a helical LSD.

Fitted some nice low profile side mirrors.

Also need to sort a bonnet- which I will need to get fabricated. Currently it has a single side draft, but the manifold is on quite a rake, so there will need to be a hole in the bonnet so the carb can protrude. A solution would be to switch to a twin carb manifold which would keep the carbs horizontal, and run twin 40's so I get full bonnet clearance, but this is a further expense, further complexity and it's running great with the single 40.  

Anyway- photo from the last outing




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  • 8 months later...

It's been a fair while.

At the second WOF in many years,  the diff whine was addressed, and a bigger battery fitted.

I attended the track day at Ruapuna in November, and there were no major issues. Drove it fairly hard too so I was very pleased. Still don't think it's quite running to the full potential however, need to have a further look at this, but have really just been enjoying having the car legal and running for the hot weather. 

As mentioned previously the next step I would like to take is change to cycle guards, but would be good to get the car running as it should before any non essential aesthetic modification begins. 

Aiming to get back on track at some point in the next few months, and get more comfortable with it, however, I am certain that it can well exceed my limited driving ability...





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  • 3 months later...

I tried to enter this on the most recent Saturday track day at Ruapuna, but my ambitious plans to get a WOF within a week were a bit too ambitious.

Failed on a lacking bracket for the rear brake hose, and the front guards were not secured tightly enough- so I remedied this with some aluminium.

Also failed on excessive movement in the steering rack end- lucky it is a shim type so replaced the shims and tightened everything up- no more play. 



Also made a new chassis plate- as it never actually had one


As it happened the weather was terrible the day of the event anyway- so took the daily instead which turned out to be a good move- photo credit to Rowan Seymour.


   Hoping to get it to the track for the next event in late June- weather permitting of course. Still need to sort my tuning issue. And I am becoming tired of being hit in the face by large insects. A windscreen is needed soon- not sure who to contact though. Any suggestions on fabricators appreciated. 





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  • 1 month later...

Made it to the last track day at Ruapuna, getting more confident with the car.

Very cold start to the day, was minus 5 when I set off- dressed like the Michelin Man looking more like I was going skiing than driving. 


Still wouldn't rev out- gets to 3500 revs and the powerband starts to come on hard, will get to about 4500 and then it just hesitates and won't rev any harder. Tacho should be reading correctly as it is new and has been tested. By ear it sounds correct.

I have taken the manifold off and put a new gasket on, and also remounted the carb to the manifold with new rubber seals. Haven't over tightened it either as I think this was the issue last time- some kind of vacuum leak. It was also running lean (occasionally backfiring out the carb itself) so have readjusted the mixture screws for both barrels and will take it for a drive tomorrow to see if that fixes it. Started up fine and I adjusted the idle so fingers crossed. 


Any weber carb experts out there feel free to give me some tips/point out what I might be doing wrong.


Car also overheated slightly, I think there may still be a bit of sludgy buildup inside the block as it did sit for awhile after the rebuild. Will try and descale it tomorrow- may even put a cooler thermostat in. Usual operating temp is 90 degrees which is about right for a crossflow?




Next track day is Saturday 14th- hoping for some good weather for it. 

Comments or advice welcomed,



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  • 2 weeks later...

Bit of a disaster on Saturday.

3 laps in, and the seal on the oil filter popped out at 100k, unloading all four point something litres out the side of the car in about 2 seconds, some of which ended up in my face.

Got it turned off as soon as possible- don't think it has done any damage. Re-seated the seal, filled it back up with oil and nursed halfway home, as the alternator decided to not charge, then got towed the rest of the way.

Inconvenienced other track users which I feel guilty about- thankfully they had something to soak it off the track with.

Anyone ever encountered issues with filters blowing seals out? Certainly a new one for me. I may be more selective in my brand choice in future...

Photographic evidence of my slippery shower on the rear guard/side of the car. It does wonders for your hair...



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  • 4 months later...


Track day on Friday went much the same as the last, with different problems. I had new brushes put in the alternator which solved my lack of charging.

I had some overheating issues last time, if the gauge is correct. Was getting up around 95-100 degrees, so I cut the spring out of the thermostat and removed the innards, leaving just the body- I've heard that crossflows don't like having the thermostat housing empty? Anyway, it didn't fix my issues. Driving to the track was fine, sat around 81 degrees. As soon as I got on track it climbed to around 90 when I decided to call it quits on the first session and let it cool. Didn't boil though. Was quite a hot day and some other cars were having issues.

I also put the old thermostat housing back on the engine as shown below. The radiator has its own cap but it is slightly lower than the head- my theory was that the air needs to escape at the highest point so it should be easier to bleed the air out? Maybe just wasn't bled properly as it was a rushed Thursday night job.


Then the throttle linkage came off, nut must have shaken itself off- got towed in. Embarrassing but relatively easy fix.

And then this happened



Throttle cable broke at the pedal end. Towed in again. Then proceeded to the nearest bottle store and purchased the event organizers a box for the inconvenience. So that was the end of the day. Pulled through the block on the accelerator pedal.


So I wound the idle up, tied a knot in the cable, put a zip tie on it so I didn't cut my hand up, and drove home with a hand throttle. There were a lot of helpful people at the track, giving advice and offering to try and help solve issues, maybe some are members on here, if so, I thank you. 

Any thoughts on the overheating issue would be appreciated/ what temp should it be running. It has a near new Honda alloy radiator, electric fan, have put descaling solution through the cooling system recently and refilled with good coolant mix.

One day I will get a decent lap in...

Discussion/ advice welcomed



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  • 10 months later...

Decided to get this out and try sort a few things. Wouldn't start at first so had to put some fresh fuel in, clean the points etc.

Started eventually- took it outside, pulled the radiator cap off and there are bubbles- was only running for about 3 minutes. Water was hotter than expected too. 


Removed the radiator to flush it out with a hose, even after running rad cleaner through the whole system awhile back and filling with a good antifreeze mix it still has rust scale shit in it. Replaced the top hose as it had a pin hole in it. Refilled and went to run it with both caps off (it has one on the rad, and one on the top of the head). Under light load it is pushing water out- so I suspect a head gasket, someone may be able to confirm my diagnosis, as I often have no idea what i'm doing...


Aside from the potential head gasket- Other contributing issues with cooling are that the bottom hose is on a fairly steep angle upwards to reconnect to the water pump, which might mean the pump has a hard time pushing water back up the hose? The top hose also angles downwards, but the inlet on the radiator also points down- again, not the easiest flow path. 


Assistance with diagnosis greatly appreciated:



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  • 2 months later...

Well, crack test has confirmed, it's fucked. 


Has been previously repaired as well. Cracked right around both the removed valves. Given the cost of repair it is uneconomic and would likely happen again anyway.

Both nice to confirm the issue, and also a bit of a pain.  

Time to figure out the next move... 


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