Roman's 4GR V6 Toyota Carina

[Roman]

Looks like intake valves are ~1mm bigger diameter than a 1NZ, exhaust valves same size. 
So if it made only exact power per cyl that the 1NZ did, (per cyl, not per litre) that's...  225hp at the wheels.
However, it'll have the advantage of considerably more lift, more duration on the cams. And then more space around each valve to flow, and a shorter stroke. 
So I think it's realistic to expect a bit more than that. 

Some insanely straight ports! 




This below is a picture of the bowl/seat arrangement on the intake side. 
Definitely some room for improvement by blending the bowl cut into the casting a bit better.
Then will smooth off the outer cut edge on the very outside too. 
The short side radius is basically absent / incredibly gross - I guess that's one downside of a super straight and high angled port. 
Not too sure what to do there, it feels like instead of a curve there it might just be the back side of the seat sticking out to form a square edge.
Maybe it is like that to tumble the flow around the corner or something. Will be a tricky spot to get to if I decide to fuck with it.




So on the intake side, probably the only "porting" that I will do will be in the combustion chamber / bowl. There's not much point doing anything to the big straight section.
But on the exhaust side, the port is TINY, definitely less cross sectional area than a 1NZ. 
So this will likely benefit from being hogged out as much as I can get away with, without hitting water jacket or whatever.
So, probably a good idea to do the exhaust first in case I fuck it up.

[Roman]

Got it more cleaned up and started molesting it with the dremel.

I decided that since the valves are small Im gonna need to try deshroud them as best possible. Even if that means increasing chamber volume slightly. Since the direct injector will be gone now, if I can get the hole welded up then it will more than amount to the material lost.

So ive been putting a radius on the squish bands. Maybe good for flow but probably bad for combustion goodness. Might reduce knock resistance a bit.ive left the side ones alone except for the exhaust area, but might carry on the profile.

 

in the ports there is a very intentional step on the short side radius, and some naca duct shaped geometry on the lower wall leading up to it. 

Likely to tumble the air around the corner for good mixing or whatever.

However it blended fairly nicely back in to make a more normal curved short side radius.

The intake and exhaust ports are remarkably smooth for a factory cast finish. Not really any point doing much to them.

There is a huuuuuge amount of taper in the runners, could probably fill in 50% of the port area at the top - but will leave it for now.

Im considering cutting the divider shorter but this might be a job for cnc.

But again, will run it this way for starters rhen make some incremental improvements/failures later once its running.

 

 

 

 

[Roman]

Some boring bits of progress. 

I've been trying to find injector plugs for the Triumph injectors. After a while I found that they are the same as late model Hyabusa ones. 
I'm still looking for the e-throttle plugs, hopefully these are something sort of generic as well. But I might just put a lead and another plug on them.

I've finished wrecking porting the heads, I ended up tapping a thread into the direct injection plugs, winding bolts in and using high temp loctite. 
I'd not do this again as I've ground the ends of the bolts flush in the combustion chamber. But some of the sharp thread ends were sort of exposed. so I've had to try grind down the threads on the sides as best I can to avoid sharp edges.
Next time press something in, instead.

I've printed two inlet manifolds from carbon nylon, as "final" versions read to run with. Just need to cover in carbon sleeve then they're done. 

I printed some clip together exhaust manifold block things when I was mucking around with the Echo. 
Since this will use the same sized pipe, figure I'd repurpose and see what I'm up against.
The hardest part will be dealing with the steering column and getting around it. 



Options are obviously to either hug close to the engine block, or go around it the far side of the column.
The problem with hugging the block is that it will work for the steering column, but then I cant do the same on the other side of the block. Because the starter motor is in the way.
So I think I'll try go outside-outside, so I can reuse same design on both sides.
In order to try get some equal(ish) length runners. In my model I've cut the pipe into 30 degree segments. Then measured the length of the arc of a 30 degree segment. Which was something like 30.2mm. 
Then the straight bits are 30.2mm long. So this means, if I've got the same number of parts on each runner, whether a bend of straight. Then the runners are equal length, or there abouts. 

Using some measurements I've come up with a scheme that I'll try make fit with printed bits in the car. 
This might end up hitting my engine mounts though. Or possibly the alternator on the front of the other bank.
I'm going to try make something along the lines of this fit. It's 18 segments each per runner, and I can still get to all of the nuts on the flange easy.
One of my other attempts to go on the inside of the column meant it would be very difficult to get the manifold off or on.








I also ordered some flywheel bolts, I found the part number from the factory manual IS250.
My engine didnt come with a starter motor or alternator. 
These two things seem to evaporate instantly on the pickapart cars. 
However I managed to nab a starter motor from the Tauranga branch. 
I really need to get an alternator fitted so I know how much room I've got for the manifold on that side.

So, little bits of progress on lots of topics but nothing really ticked off the list. Will get there!
 

[Roman]

Mike Tyson was famously quoted as saying "Everyones got a plan until they get punched in the face" 
Well, thats about as well as my equal length exhaust lego has been going. haha. 
My scheme for equal length was nowhere close to working, mainly because of the engine mount below the middle cylinder making life hard. 
It's also been difficult because of the Vee angle - you can make a nicely fitting thing that works. But then you cant get the damn thing on or off as it wants to hit the chassis rail.
So it's looking more like it'll need to be a bit more compromised on lengths until everything's past the steering column. then can maybe do some swishy bits to bring them close to even again. 

So, what do you do when something is too hard? Have a sook and ignore it. 

So here's some progress on the intake. 
Same recipe as the echo, which seems to work well enough. 
CF nylon PA12 print, then carbon sleeve over the top. 
I've been talking to @flyingbrick about our concurrent CF projects. 



I thought I was making some manifolds, but turns out I was making a 6 pack of chodes



Then tidied up a bit 



Then very nearly finished! 



 

[Roman]

My next problem. 
My idea has been to reuse the beams 3SGE flywheel, as I know the distances etc are compatible with the gearbox without too much brain work. 
Problem with this, is that the beams motor uses an M12x1.25 flywheel bolt thats 40mm long.
As it has a dual mass flyhweel that's 25mm thick and 15mm into the crank. 
However the GR motors use the much more common M10x1.25 (hooray) but in a length that nothing else does (oh no) 
Most flywheel bolts in this size are something like 25mm or 30mm long instead.
I found the part number for the 4GR flywheel bolts for the IS250 and ordered some a little while back.
These turned up today. 
(1NZ bolt on left, 4GR on right) 



Definitely way too long. From factory they must have a super chunky flywheel! 
Must be around 40mm thick dual mass setup. 
I'm not sure what's next, because I'm not sure if flywheel bolts are anything overly specific.
Or whether regularish M10x1.25 40mm grade 12.9 bolts will be the same thing?
I've emailed ARP to see if they have anything 40mm long, but doesnt look like it. 

[Roman]

Big thanks to @HumberSS for helping me find what looks like the right flywheel bolts! 

If this image ever expires, it's part number 90105-10207 




So I've ordered some of those, so I'll plan to persist with the 3S flywheel for now. 

So then I also need to figure out how a gearbox adapter will work. 

Scaling from some drawings of a 4GR bellhousing pattern, and also a 1MZ bellhousing patttern (As this essentially matches a 3S, apart from starter position) 

I've lined them up to see what sort of options I've got. So hopefully all of the holes clear each other etc and I'm not having to shift gear upside down or whatever.

Highlighted blue is the 3S-ish bellhousing pattern, then the grey one is 4GR. 

It's looking preeeeety close that I could slot some of these holes to get a few bolts in. 
So it'll still use an adapter plate, but just means some of the bolts can go all of the way through. 

Then the rest will need to use flush mount cap screws, or studs that wind in, or whatever. 

The bellhousing outside diameter is small enough that I can print a full sized adapter plate to test with before butchering any expensive materials.

The starter motor position is a bit annoying, because one of the 4 main bolts needs to go there, but wont be able to.

[Roman]

On todays episode of "weeelllll shit" 

My injector plugs turned up, and they do indeed fit Triumph injectors. 
However, some dumb dumb forgot to allow space for them to actually fit when fitted

There's enough space that I could pot the plugs and run some other plugs at the back of the engine. But I'd rather keep it a bit more friendly for replacing bits later on if needed.

So hang these on the wall of shame

 

Time for a rethink. 
If I turn the throttles around 180 and try run them as close together as possible, but laying flat like so.



Then I need a minimum of around 140mm from throttle on one bank to the other. 
Which pushes them out wider than the centers of the ports, so ends up a bit like this.

However, will give it a try so I've got one on the printed that should be finished by the morning. 
I've made it a little taller than needed, so if it looks like it'll fit and work okay, I'll drop it down by however much.
 

 

 

[Roman]

This is looking better, with the throttles flipped so rails are in the middle. Actually has better clearance to the bonnet, and to all the plugs... and doesnt look so gumby.

Might try sit them a smidge lower then will print some nylon versions.

Excuse that one bank sits lower, there was a powercut during the print.

 

 

[Roman]

It's a bit of an optical illusion, because the outside profile of the runners is different to the inside. 
The first top 10mm of the intake needs to be circular, so the silicone joiners can clamp on. 
However, the inside diameter starts its change of shape right from the top.



'The problem with tipping them outwards to more of a vee, when the rails are in the middle. Is that the fuel inlet pipe into the rail starts sticking vertically up. 
The fuel rail is made out of nylon so I dont want to take my chances breaking off the fuel feed hitting the bonnet. 
I might remake the fuel rails at some point so they are rear feed anyway so it looks a bit tidier. 
But lots of other things to figure out for now.

Plus there are other benefits to having them vertical (it looks a lot nicer, makes an airbox easier, actually allows more room for runner length surprisingly)
 

[Roman]

To hid the ugly wiring and improve aesthetics I think I'll make some engine covers. 
Seems easy to follow the natural contours of the top, then the two looms can come together in the backside of the engine.

 

 

In actual wiring news though, it looks like the Triumph TPS's are made by Denso - who is basically Toyota. 

Looking at the plug shape - looks identical to 4 pin Altezza TPS. Ha! 
Hopefully it is, then that's another problem solved.

[Roman]

Looking at the exhaust situation some more, I've realized that I dont have a manifold problem. I have an engine mount problem. 
They're just stupidly far apart / away from the block, and they're right in the way.



As although it would be cool that I could use the factory alloy mounts, and I've persisted with that idea. 
They're just a pain in the ass being so wide apart. 
Not only does it cause exhaust issues, but it makes the motor hard to get out as well.
With the motor back supported on jacks and the mounts taken off, there's an absolutely glorious amount of room for exhaust.
So I might be able to fit in my original swooshy design.
Although I need more on the to-do list like I need an extra hole in my head. 
I think it makes sense to remake the mounts to make life easier later on.

Since engine mounts are small enough to plonk on the scanner bed I tried that method to get a copy of the bolt patterns.
It can be counter intuitive where to put gussets until you model in the size of the socket needed to undo stuff. 
I'd 3d print a pair of these for a test fit, but my printer has shat the bed fairly spectacularly.
I need to get some flanges cut for exhaust manifolds so I'll just get these done in the same batch. 
Anyone know a good place to send DXF for mild steel plate cutting? 

[Roman]

Thanks to some input from @Stu I've added tabs onto everything so it should slot together nicely making it easier to weld. 
So two exhaust manifold flanges then the rest are engine mount parts.
Be cool to see how it turns out!

[Roman]

Hot out of the @StuScience(tm) laboratory we have a test sump cut out! 
I didnt notice at first but the bottom layer is clear sitting underneath.
Exciting!
I hope it all fits up nicely. 



If it all fits, plan is to make the top two  pieces from a single piece of 20mm alloy plate. 

In other news my 3D printer completely shat itself, and parts to fix it are a few weeks away. 
So I started thinking about outsourcing some prints to get my new manifold shapes finished.
Then realized there are high end powder printing machines that are fundamentally different (better) to what I can print myself. 
So I had a look around and fired off some quotes. 

Two manifolds for the 4GR came back around $250 shipped. 
Pretty sweet! 
So this is MJF powder based printing from PA12 nylon. 
The benefit of this is that its equally strong in all directions, unlike "normal" printing which is weak on the layer lines. 
Ends up with a cool textured finish like this.
I'm hoping that it wont need a carbon coating in order to be strong enough, so it'll considerably cut down on my hours needed to make parts.
They will be a few weeks away, but if they turn out good I'll likely get a few other bits made this same way. 







 

[Roman]

I yanked the motor and box back out, and tried on the sump. 
Good news is that all of the bolts do up nicely!
Test cutting from the foam stuff was a great idea, this is an awesome material for test pieces.
Quite rigid but easy to cut with a blade if needed.
Which was needed, in a few places to clear the windage tray. So will update my drawings.



The total thickness of the sump will need to be a little more than the 20mm. As the clear perspex layer still hits on the windage tray. 
This might just mean the bottom layer ends up a bit thicker, with some amount dished out to allow for the tray.

I'm trying to claw back every possible millimeter here though, so I've got more space up top.

[Roman]

The lasercut parts turned up. 
Holy moly I cant believe how good the finish is! 
I was expecting raggedy sort of edges but they look amazing.

The mounts all just slotted together perfectly, before there's even a single tack weld. 
This would have been really fiddly without the tabs added.
It holds all of the angles etc perfectly.
(Another good Idea from Stu - thanks)




So, while I was busy congratulating myself, I decided would plug weld the bejesus out of the back of the tabs instead of tack welding them and test fitting...
I put the mount on one side together inside out, so the lower bolt holes dont line up. Woops. 



With some effort I could probably cut the welds back out, but I really did choose the worst place possible to weld them together initially. 
Since the finish is sooooo nice from the laser cutter, and I'll only make a mess of everything trying to fix it.
I'll pay the dumbtax and get the parts for this side recut. 
Regardless, it feels like I'm making good progress on things at the moment.
Dumb to put it together inside out but I'm happy. 
 

[Roman]

With the smaller mounts theres definitely much much much better room for exhaust activities! 
Before I get too carried away though. I really need to get an alternator mounted on the block, and get the engine mounted in it's final spot. 

I'm making good progress on those topics but was a relief to see how much more room there is anyway. 
Will be worth the trouble. 
It's a tricky job even just with the lego bits, definitely takes some skill and experience to fabricate exhaust manifolds decently! 
Currently the #1 runner is the trouble child, needs to be longer (Can see that runners #2 and #3 have 3x 90 deg bends, vs only 2) 

However I cant swing it forward too much because stuff's in the way.
Then I also need to make sure that the manifold can physically be removed, but again that's much easier without the giant mounts.
The aim is to have a mostly decent plan before I start chopping any expensive bends up.

[Roman]

After some IRL lego time.
Back to the model to try replicate my best plan, and see how even it is.
Answer - not very.
I've been trying a few iterations back in the model, just brain storming ways to arrange the pipes that keeps them even lengths. 
And hopefully doesnt look derpy and is also easy to make.

A few non starters... Too complex and also quite ugly.



Not sure what to do, so went to google images for some ideas.
Decided I need to go back to basics.
So make the #1 runner with fewest bends and shortest length possible - then for the others, remove straights and add bends until they're equal. 
Ha! Works quite well. And each runner is on a flat plane so they're easy to make on the bench.
These are within 22mm centerline length of each other. sweet. 
I hope there's space to make it work.

[Roman]

Much better! Will be fairly easy to get this to work around the steering column i reckon. Fingers crossed.

Will probably change the front runner to two 45s spaced apart, so it matches the shape of the rest a bit better.

But will order some pipe soonish.

[Roman]

New manifolds turned up, and hooooly hecka they are amazing! 
No infill, no layer lines - fully solid so they feel really strong.
The dividers have a super sharp leading edge on them, and all the details are great.
I think from now on, I'll keep using my printer mainly for PLA based prototyping, then will have final parts made this way.

[Roman]

Started pooing together a manifold.

Too tight damnit. Will have to tighten the bends a bit with a few angled cuts.

Also, the only way I will ever get these off or on is by lifting the motor. And all of the studs in the head need to come out or its impossible.

A bit of a hassle but better than having the shitty standard log manifolds.