Roman's 4GR V6 Toyota Carina

[Roman]

 

Long time no post. 
I've had this car for a long time, so it's not really a new project. 
However, it's been dormant for the last few years while I've been mulling over options for a new engine.

New motor Criteria:
-Capable of big rpm 
-less weight than beams motor 
-newer motor / alloy block 
-Be nice if it bolts to a J160 without adapter

These are some of the engine options I've been going back and forth between:

1NZFXE NA 
Probably a bit too slow for a ~950kg rwd car... But maybe alright with a diff ratio change. Would definitely be the lightest option.
Lots of room for activities with intake etc! 

1NZFE+turbo
This would be great because it would achieve nearly everything I want (lots of rpm, a power increase, less weight) 
However I do prefer NA motors for ease of working on but also tuning is more fun I think.
This wont bolt up to a J160 directly, so that's a headache not present with some other options.
Also the exhaust runs down the drivers side which is a bit annoying.

Bike motor 
I am keen to do a bike motor project, but, I think this isnt the right car for it. Too big/heavy.
But how cool are bike motors? Built with amazing ports, mega rpm, and sequential box that can shift near instantly. 
Bloody good. It just really excites me to buy a 10 second bike and turn it into a 14 second car haha.

Have you considered a 2ZZ
Yes, yes I have. 
Pluses to this are that it's lighter than a beams motor, VTEC! and built from the ground up for lots of rpm. 
Good power potential. 
Downsides - motors are hard to find, that arent either clapped out from high km, or needing to buy a whole car to get an engine. 
Needs a bellhousing adapter, exhaust runs down the drivers side (steering column/brake master cyl annoyances)
Niteparts is currently working on fitting a 2ZZ to AE86, really excited to see how it turns out.

2ARFXE or 2ARFE 
This is a big late model 2.5 liter 4cyl motor that's gaining popularity for modding. 
The FXE version uses the same tricks as the Echo motor, however, the factory cams have some pretty decent lift and duration unlike the 1NZ.
So it looks like the popular cheapish option is to use a second intake cam in the exhaust side, then you've got 270deg cams with 11mm lift. Pretty sweet. 
Downsides? It's a tall bugger. I'm definitely not wanting to do anything that requires cutting the bonnet. Might not fit. 
Also, it would be weight neutral rather than losing any weight from front of the car which was one of the goals. 
Since it has quite a long stroke, it probably cant rev as high as I'd like. I'm more concerned about engine sound/feel/revvyness rather than outright power.
It's a good option, especially if it can bolt to a 3S bellhousing - but being rpm limited to 7500 or something. Blargh! 


So, yeah. Those were the options I've been considering and trying to decide between. 
However while browsing through Dodson's trademe site for cheap big block 4 cyl FXE engines I spotted something interesting that I'd not considered...
A new challenger appears! 

4GRFSE 
Now this is a bit of a WTF option but hear me out.
The 4GR's big brother, the 2GR. Is a 3.5 liter V6 that is commonly swapped into MR2s etc, because can bolt up to a 3S bellhousing. 
However most of the 3.5 liter versions suit having the motor tipped over for east/west config.
I think you need to buy a Lexus motor to get the RWD config motor, and uhhh yeah. Lexus tax.
The 4GR is the 2.5 liter direct injection V6 from a Toyota Mark X, which is setup for FR config.
It's got a rear mounted sump, which by eyeball should easily fit behind Carina crossmember.
Also, they're cheap and readily available as Mark X are a fairly common car.
Why not 2GR for an extra liter of displacement?
Well, the 2GR makes good power but it's got a big bore, big stroke, and will be rpm limited on factory pistons to less RPM than I'm willing to settle for.
The short stroke and smaller bore of the 4GR motor means pistons/rods are lighter and the mean piston speed is considerably lower at a given rpm.
To be honest I've never really considered a V6 because I think a 4 cyl motor is more in keeping with the spirit of the car. 
But when you look at the numbers, there's no way to get an off the shelf 4cyl motor that has a big enough bore and short enough stroke for mega rpm.
Even the tiny 1NZ has rpm disadvantages compared to it.
Another interesting aspect, is that since this motor is DI only from factory. It doesn't have any injectors in the ports, which usually seem to result in more angle on the port. 
In this case the DI injectors are mounted below the intake ports, so it's got STEEP intake ports. Another good sign for high rpm.
The downside is that as per every DI only engine, the intake ports clog up with shit. Solved by converting back to regular injection.




Still thinking "why a V6?" (boooo)

I think it's going to be possible to get a semi reliable 10k rpm from this motor. 
Honestly how many engines are capable of running to 10k? How good is that.
If these numbers stacked up the same way with a 4cyl motor, I'd use that. But they dont.
Also to remove any doubt of this motors absolute peak performance potential this son of a bitch has a modern day TVIS equivalent. shit a brick.



I've come to realize from the echo that revving the absolute bejesus out of something puts a smile on your face for longer than outright power does.
This motor, the bottom end at least, should be 10k rpm capable with considerably less stress on the motor than any other option from the Toyota stable that I can see.
Here's some graphs, because, well, it's my thread and thats how it goes.

Bore size
4GR is about middle of the range for bore size, which is a good indicator of piston weight.
Keeping in mind that piston area goes up non linear to diameter, so only a few mm more can mean a considerably heavier piston.
pistons will definitely be a a fair chunk lighter than 2AR or 2GR options.



Stroke length
4GR has got by FAR the shortest stroke out of options.
Nearly 8mm shorter stroke than a 1NZ.
Considerably shorter stroke than a 2ZZ, which is a pretty good benchmark for a high rpm capable engine.
God damn delicious!


Compression ratio
Lower than some of the options, nothing beats the 1NZ!
However 12:1 is still awesome, the fact it's a non hybrid factory engine with CR that high is great.


Rod length
(Thats what she said)

2AR has the longest rod, but it's also got the longest stroke. 
Apparently the 2GR and 4GR have the same rod length, which would mean the 4GR block must be more compact. 
Good news for keeping the engine height down a little.
Nearly 10mm longer rod than a 2ZZ.


Rod/stroke ratio 
The highest the rod/stroke ratio number is, the straighter the rod stays when travelling up and down the bore. 
So less side loading on the bore. This is generally considered a good thing for high rpm, and it also changes how long the piston dwells at TDC and BDC. (higher number favorable for more rpm)
An S2000 has a rod ratio of 1.82:1 
Having a 1.92 rod ratio is god damn glorious for high rpm from a factory engine.




Mean piston speed 
Rather than picking an RPM and listing the mean piston speeds, I've chosen a mean piston speed (4500 feet per second) then shown how high each motor can rev when reaching this number.
The 4GR does wees over everything else. 
Keep in mind that I'm revving 1NZ to 9k currently, which would be same piston speed as nearly 10k with the 4GR. (4GR will have a heavier piston though to be fair)




Sooooo yeah. 
I think a 9500-10,000rpm motor should be doable, as there are big cams available.
If so, it will be friggen wild.
Well, there are big cam and stiff valve spring options available for the 2GR - but I'm not yet sure if these will fit the 4GR.
Looking at pictures of the head gaskets, it looks like the 4GR has the same bore spacing but just bigger gaps between cyls.
I've bought a motor to test fit everything initially. It's not much of a gamble as they're reasonably cheap. 
I'm hoping things will all work out, but there could be some issues yet.
Good thing I got some practice using a hand drill to modify engine blocks with the 1NZ. Might need these skills.
Here's a few pics of the next modern Toyota FE motor I'm planning to turd polish into oblivion. 





I'm super excited about this! There's still a zillion reasons why it might not work out, or something doesnt fit, or blah blah blah. 
But if it all works how I'm hoping, it's going to be cool as hell.

[Roman]

So a basic overview of where I'm currently at, and where I hope to be.

 My Carina has been running a beams 3SGE motor for many many many many years. I think I bought the redtop motor for it in 2005!
And it's been awesome. 
I've also done heaps of driving in the car and I've done my best to keep it as a nice weekend car and a bit of an all rounder.
It's been great! 





However, as time has marched on the state of Altezza engines, and Altezza owners, has deteriorated considerably. 
After having the echo project, where it was like working on a brand new engine. I decided I wanted a new motor for the carina that was a bit newer, still common/cheap, and where the average kms isnt hovering around the 300,000km mark. 

So, for that and a variety of nerdy reasons I've outlined in the tail end of my beams 3SGE thread. Time for a 2500cc 4GR V6. Exciting! 

This is the motor that I've bought, but not picked up yet. Unlike the other GR motors this one is designed from day dot to plonk into an upright FR configuration. 
Also, it somewhat bolts onto a 3SGE bellhousing pattern, so I can use my existing J160 gearboxes with it.

[Roman]

Here's a list of the major problems I think I need to address, but dont have 100% answers for yet. 

Engine fitment in the bay
Obviously I dont have a way to confirm this yet, but it looks like the engine mounts should sit on the Carina crossmember nicely, and the rear sump position should have plenty of room behind the standard carina crossmember.

The only picture I can find of an empty engine bay is ths one from about 65 million years ago when I first painted the bay. But you can see there's a generous amount of room behind the cross member, and both sides of the firewall beside the tunnel slope back at about a 45 deg angle - because these cars came fitted with motors that ran the exhaust down either side of the motor, depending what motor.

The steering column looks like a problem here, but I dont think it was fitted at the correct angle in this pic. And I think this pic is misleading about the angle. Hopefully it's not an issue! 
It's looking like I might be able to sneak the 3 exhaust pipes right beside it hugging the motor, but we will see.



Mounting engine to J160 
So I found a single forum post, saying that someone tried this with a 4GR motor and it was reasonably successful.
They confirmed that the bellhousing pattern is the same as a 2GR, because the 2GR is very commonly bolted up into MR2s as a 3SGTE substitute.
The main problem is that the Altezza box usually bolts the starter motor to the engine side, very close to the block. 
But now that the block is a vee, the starter motor wants to exist where the engine does. 
o it looks like I might need to find a starter motor that spins the other way, and mounts from the other side. 
Easy enough though, as that's how all of the east-west motors run things. Or the auto 4GR starter motor will work fine like that.

Clutch and flywheel
It looks like a 3S flywheel doesnt work. They both have an 8 bolt crank but maybe the PCD is different. 
Either way, my Altezza flywheel wont work because if I'm starting the engine from the other side, the teeth need to be cut the other way. 
Good news is that a 1MZ (earlier toyota v6) flywheel does in fact work. There are a few light weight aftermarket options available.
Since there is normally a spigot bearing for the J160 box, which isnt present on the FWD boxes. And the mounting face of the dual mass altezza flywheel is reasonably far from the motor. 
I might need to look at some sort of solution that maybe machines down the face of the bellhousing, or spaces out the flywheel or something.
Otherwise the nose of the input shaft will not be supported, and there might not be enough spline engagement. 
Thankfully I've already got 2 j160 bellhousings off the boxes, so I can easily do some mockups and so on to figure things out.

Will 2GR cams fit? 
Signs are pointing to "mostly sure yes" 
I have confirmed that someone has fitted a 4GR crank into a 2GR block. 
Then also confirmed that the spacing between bores is the same for both motors.
So it's looking pretty good for being a direct swap over, but I'll obviously need to try confirm this before I get too carried away with everything else.
As if the 2GR cams dont fit, I'm basically dead in the water for my rpm goals.

Intake manifold / converting to port injection
Interestingly the 3.5 litre engine has both direct injection, and port injection. 
So this motor has a very short port divider, deep in the port. 
In the toyota documentation it states that the rationale for this, is to minimize the port area that can be affected by wall wetting from the port injection. 
Because it fits the injector above the port, the port is angled down a bit closer to horizontal. 
It's a bit more of a classic looking 4 valve intake port:




However, the 4GR motor is direct injection only. So there is no port injector on top - So they run a much steeper port angle. 
Also, the motor runs a TVIS style system where it closes off one valve at lower rpm for better mixing or whatever. (not shown)



Super steep ports!
So I'll be mounting injectors much further up the intake tract. But I think I will keep the port divider nice and long, and print an intake which continues this further up closer to the throttles. 

Here's a cross section of what the intake ports look like. How about that nearly non existent short side radius. Bloody good.




I found a scanned copy of the intake gasket, and based on the bore to bore center of this motor (105.5mm)
I scaled the drawing. This wont be 100% accurate as the gasket usually sits a 1mm or 2 inside of the mating surfaces. 
But from an initial eyeballing the port has equivalent cross sectional area to about a 52mm circle. So we can likely say the actual port area will want something like a 48mm or 50mm throttle. 



So to solve 2 problems at once, Triumph comes to the rescue (maybe) 
The Triumph Tiger 1200cc motor is a 3 cylinder engine with a 90mm bore. 
So the port spacing should be fairly equivilent to this motor hopefully. 
It would be awesome to be able to run a twin e-throttle setup, and avoid the need for balance bars, cables, and all of that stuff. 
It would also provide a convenient place to mount some injectors, and the fuel rails.
The Triumph motor makes 140 horsepower with 3 cylinders, so with two of them it will have easily the injector capacity for 300hp or whatever. 
But maybe not, because when you are doing mega rpm the deadtime of the injector becomes a major element of determining the injector size needed. 
But we shall see. 
One problem with any off the shelf setup like this, is going to be that there isnt a mirror image version of the throttles available. 
But, that might work out alright so there's better clearance between the e-throttle motors in the engine's V. (thats what she said. or something.)





My next problem is that my ECU cant actually control 2x ethrottle units. There is a canbus extender that allows e-throttle control to ECUs that dont have it - But I cant use the onboard H-bridge as well as the external one, for whatever reason. 
I'd need a G4X ECU in order to do that, which is quite a lot of extra money. So, will do some more head scratching on this one. 

That's all for now.
Hopefully pick up the motor later in the week once the storm has settled a bit. 
 

[Roman]

I found some reasonably good high res images of a 4GR block from front on, top, etc that didnt have too much perspective distortion. (good work camera man)
So put these into cad and scaled them to size. 
One awesome thing is that the flanges for the intake manifold on both sides sit on a flat plane. 
The factory lower part of the manifold is machined flat as a single piece across the bottom. So if I need to make a manifold that is one single part it's easy.
So I can get some rough sort of start on ideas for making an intake.




Then I took some measurements from the existing motor in the Carina. it looks as though currently I've got about 440mm from the centreline of the crank up to the top of the motor (With more clearance the further back everything sits) 
So I'll try work to this for starters.
Dark blue line is height limit to try work to. Might be tricky, but also I've probably got a fair bit more room than this in reality. Especially if the engine sits a little further back.
Thankfully the valve covers are quite low height and hug the contour of the pulleys reasonably well.










Really need to know centers of throttles, and diameter etc before I can get too carried away though.

[Roman]

Got this home and stripped a bunch of junk off it.



And jesus jibbly christ it is MONSTROUS. 
Here is a 1NZ cam cover compared to 4GR to show size.


I thought being a V6 it would be a fair bit shorter than beams motor. But looks like it might be even longer. 
To be fair a lot of the front of the motor is just empty spacing holding the timing chain etc, so the centre of mass is further back than it visually appears.
However there are some other issues.
My engine bay tips in at the middle a bit to accomodate the motor sitting back. But it does not do this where you need to fit a Vee motor. 

So to get this in a position that will fit the rear sump, it looks like it'll need to choppy chop heaps of this out. 



Which is even more troublesome on the other side, as that's where the brake booster etc wants to live. 

If I try put the motor further forward instead, I dont think the rear mount sump is going to fit past the crossmember. 
The whole motor is just way way bigger than I was anticipating hahaha.

Here's a pic of the 3S bellhousing placed up against the motor.



It looks like the east-west 2GR motors do have the 3S bellhousing pattern, but they totally changed it for the north/south motors which is annoying.
So at this stage, pretty disheartened. This thing is honestly monstrous and feels really heavy too.
I dont want to have to chop a massive amount of my car out to make it fit.
The difference in overall size from 2 litre beams motor, to 2.5 motor for this is insane.
I guess that makes sense when considering the block size is essentially for a 3.5 litre motor instead.

What to do from here? Dunno. Need some time to think about it. Not so confident it's the right choice anymore.
However I think I'll at least try get it sitting in the engine bay and see how it looks. 
If it can physically fit okay, will perhaps try persist with solving the other issues. 
But I dont think I'm gonna "hand drill engine block" my way out of this one. 
 

[Roman]

Disregarding gearbox issues for the moment.
Because there's no point fretting over fitting a gearbox, if the motor wont fit anyway.

I moved the car and got the old motor out, and did a test fit. 



Did some chop chop of the firewall after this photo to make one of the banks fit. 
But then with a gearbox on it's basically impossible to get the motor in because of the rear sump.
It cant get past the engine mounts or the steering column, which is a pain.

So I batted with it for ages, ended up cutting engine mounts off, dropping steering rack, then even dropping the crossmember to see if I could get it to fit that way. 
But still not working. As the gearbox wants to hit into the tapered part of the tunnel before the motor is far enough back for the oil filter thingy to clear the swaybar, and the sump to fit behind the crossmember.
It just wont fit.
So finished the day thinking it's probably a bit too big to work.

But, after some sleep and thinking about it.
I dont have an engine problem, I've got a sump problem. 
It's the stupid rear sump that is tripping me up, not the rest of it.
So rather than chopping more tunnel and firewall I'm gonna take the sump off then see how we are looking. 
Chopping and changing to a front sump is probably going to be the way to go. 
Thankfully this motor is really designed with a front sump in mind anyway. 
The 2GR motor has the sump at the front, but doesnt necessarily fit this engine - and it wont necessarily clear anything anyway. 

This is what the sump currently looks like.





Is there a Briscoes sale on sumps? 
Because there's about to be 50% off 
 

[Roman]

With the sump off everything's a piece of cake! 
Just slides in from the front, easy as. 



I can still push the motor a fair bit back , should be able to get the centerline of the first cylinder fairly close to being in line with the struts. (on this bank at least) 
So that should help the weight distribution a bit.



So, that's  good news. 
There's also some fairly decent looking clearance to the bonnet line as well. 

There's a decent amount of room for a front bowl type oil pan on the front. 

So will make some engine mounts, get it in the right place then start drawing up a sump. 

[Roman]

Sump situation. 

So the rear sump is definitely not staying.
With some discussion with @Stu we have decided that fabricating a full sump is likely the way to go - So my job is to draw something up so then he can do the hard part! 

So for starters here are all of the critical areas that the sump's function needs to accomodate: 






Oil pickup tube
We just need a new tube that will run to where ever the new oil pan location is (at the front) 

Oil filter in/out 
I am thinking I will have some tapped threads so we can run some AN lines here to a remote filter, which makes adding provisions for an oil cooler easy in the future (if necessary)

Oil drains from the head
These are very important not to block up! As other wise the heads will fill up with oil and the sump oil level can drop low. 
These are the trickiest part of making a new sump, as they weave in and out of the factory bolt holes. Meaning it's hard to use a straight piece of alloy to form the walls anywhere.

Current idea 
Untangling the oil drains from the bolt holes is what needs to happen. 
So I think the simplest way to do this is with two pieces of plate. 
The first plate bolts on using standard holes, then has some tapped threads in it for the second plate to bolt onto, from the new perimeter of the sump.
So all of the old bolt holes will end up inside the sump, but I can have oil drain channels for the heads which keep the effective width of the sump potentially narrower than the factory one for oil that drains back down from oil squirters, bores etc.

[Roman]

If the above is hard to visualize (makes sense in my head) 

First plate that bolts to the motor will look sorta like this 




Second plate / main sump part will end up looking something like this 

 

[Roman]

I put together a quick(ish) silent film showing my methods for designing and 3d printing manifolds. 

Maybe helpful for someone trying to prototype something. Basically, if you know how to use lofts and fillets you're golden haha.

 

 

[Roman]

My trick for drawing from a scaled picture worked out really well! 
It's not perfect, but drawing from measurements alone it would usually take me a few iterations to get this far. 




So I decided I'd try the same trick for getting some measurements and shape from the beams 3sge oilpan which I'm planning to use. 
So as mentioned earlier, taking a photo from far back and zooming in, and trying to get as square on as possible minimizes distortion and gives a more accurate image to work from.

Then I added that shape and measurement to the model 

 

I'm just printing the front part of the flange that fits to the motor, to see if it's all looking good. 
Then I'll print a bottom front part and see if everything's sweet, and if it's possible to do up all the bolts. 
Then go from there.

 

[Roman]

Also, something has been boggling my mind a bit. 
Lets say you have two 2500cc engines, one is 4cyl and one is 6 cyl. 
Lets say they are both doing 6000rpm and both have 100% VE at full throttle. 
Does the v6 make more power because its breathing more air in, because its got more cyls and more valves?
No, because they have exactly the same amount of airflow going into the engine.
As displacement is the same and VE is the same. The V6 just cuts the pie into more slices.

So what's the point then?
Well, hopefully with a V6 at high rpm the VE number can stay higher as rpm goes up, as there's more valve area.
So for example a K24 motor has a 36mm valve with a 5mm stem, a total valve area of 7984mm2 with its 8 intake valves.
A 4GR has only a 32mm intake valve, and assuming 5mm stem as well. On total area it wins by 17% with a total valve area of 9408mm2 with its 12 intake valves.
So hopefully the idea is that when the 4 cyl motor's valve area starts becoming insufficient towards higher rpm and VE drops off, the V6 still has enough valve area to keep flowing well.

I'm really pinning all my hopes and dreams on this motors ability to rev really high, as it's the only real upside to this big chonka.
It's still possible that there's some fundamental reason why it wont be able to.
Like maybe the crank will break or the oil pump will explode or whatever.
Also, I am very cautiously making comparisons to a K24 because it's unlikely that it will make power as good as a K motor setup will. 
But, forgetting the power figure. What if it does rev well and everything's okay, and its absolutely massively awesome? How good!
That daydream is alluring haha.
 

[Roman]

I somehow messed up my sump scaling. 
I printed the first half of it, and it was about twice as big as needed haha.

So started again from scratch because it messes things up if you just try rescale it.

So the good news now, is that I can fit whole sump on the printer at once. 




And the beams oilpan might fit pretty awesomely to the shape. 
See how it goes.

[Roman]

I have had to narrow up the sides a bunch, as it's tight for clearance where the steering column is, and the brackets for the steering rack. 

However, getting closer towards a workable plan. 

One annoying thing is that the edge of the front pulley hangs down lower than the bottom of the motor, so will need to allow a notch or whatever.

Will move the oil pan about 50mm forward of this point so its got heaps of clearance to the crossmember to make life nice and easy. 

This will also mean I will be able to weld a little upstand piece on it, to fit the 3SGE dipstick as well. Then the only hard part left is figuring out the oil filter lines.





 

[Roman]

Few bits of scatterbrained progress, on everything but the sump. haha.

I pick-a-parted a Mark X radiator and fan assembly, as the radiator hose sizes on this motor are real big.
It's pretty big, but it clears the bonnet. Sits too high for the hoses to line up which is a bit meh. 
But, keeps things simple in a lot of ways I guess. 

 

Also one set of throttles turned up. Took some quick measurements then printed just one runner to test fit. 





Has an alriiiggghhhttt amount of clerance to the bonnet. But these throttles actually have a massive head height above the throttle plate. 
So I might machine them down a bunch, so I can start a curve on the runners earlier. 
Just printing another iteration that's about 10mm taller, and a little less angle. 

The throttle spacing is not quite as good as my guesstimate with the 1NZ / S1000RR throttles.
Should be alright but longer term will probably try come up with something that keeps them all straight.




Also, I'm glad I didnt jump the gun and buy a 2GR or 1GR or whatever flywheel.
It looks like all 3 motors have different PCD on the crank.
Which is good news for me, as the 4GR is closer in spacing to the 3S than the 2GR is.
With a real life measure / eyeball it's probably close enough that put my chromoly flyhwheel on the CNC machine to slot the holes and it would be sweet.
This would make life a bunch easier for the gearbox situation as well. As the other FWD flyhweels dont have allowance for a spigot bearing that the J160 needs.




Also some random trivia, there is a 4WD Mark X. As seen at Pickapart. 
Unfortunately the sump is considerably less useful than my existing one, and looks like a bastard to get out. 



I dont know why a 4WD Mark X needs to exist, 210hp in a 1600kg+ car surely makes for a pretty sluggy driving experience.

I've gone through a few more iterations of trying to simplify the sump situation but I'm not quite happy with it yet. 

[Roman]

I got both sides fitting nicely. Sweet! 

I guess I should try find some injector plugs and TPS plugs that suit the bike, hopefully they're fairly generic. 

[Roman]

I'm pretty close to final version for throttles I think. I've pushed the pairs a little closer together towards the center of the vee, so hopefully still fits okay.

 
I've added allowance for the injector and added 10mm of straight section to the top of the outside profile, for the silicone joiner to clamp onto. 
So although it looks a bit derpy on the outside shape, the inside shape means the injectors should be spraying more towards the center of the port rather than onto the walls.






So that's nearly one job finished. Only about 50 other things to figure out!

Also, I was talking to my Dad about ethrottle situation. 
He said that I should stop being a little bitch and just make something to control the motors over canbus
(Actually he didnt say that, he's a great person) 
But, yeah, it's not actually all that complex to control a DC motor with a PID routine and an H bridge I guess?
Then I could add a feed forward table so it works better than the standard setup.

The MaxxECU actually has a way better e-throttle control scheme than Link does, in some good detail here:
https://www.maxxecu.com/webhelp/settings-ethrottle-throttle_control.html
So I might be able to make it work a bit better than standard.
Will get someone smart to review my code though so I'm not gonna kamakaze myself into a wall because I divided by zero or something.

However, the ECU would still be accepting all of the inputs, and still be in control of safety shut off features like killing power to the e-throttle relay if it sees a fault.



However this does mean that I'm absolutely nuking my ECUs allocation of analog inputs. 
So if needed I'll try push some more stuff to canbus, and keep critical things direct to ECU.


 

[Roman]

I've bought a Corvette fuel filter, someone mentioned somewhere ages ago that it has an internal FPR, and runs at 60psi.
So its an easy way to make a "returnless" setup when there's no provision for an FPR on the rail.
After the filter I can just tee off the fuel lines from there to each bank.
Will keep the quick release fittings on the fuel rails and make up some AN-6 lines to them.
I will need to reroute my fuel hard line a bit though, as I'll have exhaust pretty close to it now.





I bought some of the cheap/common dual H bridge boards (L298n) to run the e-throttle motors, but reading further people say that these are quite inefficient (so run hot, and have a big voltage drop to the motors) 
So might not be as snappy on throttle response as I'd like. 
However, they're here so I can at least put together a prototype of sorts. 

Doing some further digging around and people reccomend the mosfet based ones instead, my ECU uses a mosfet based setup.

So got these. 

BTS7960 43A H-bridge



Will wire everything up to my ECU and then start writing some code. 
I will hopefully get everything that the e-throttle module needs into a single CAN frame, maybe two.
Then run it on its own canbus network with nothing else on it. 
Will run the widebands and dash on the other canbus line.


Other stuff on to-do list currently: 

slot flywheel holes
This is with Dad, hopefully finished on CNC machine this weekend. 
Then will bolt it up and take a look at bellhousing situation once I can center the gearbox on the spigot bearing.

Sump 
Pretty close! 
This version would be good to go, except for that I'd prefer the pan to be a little further back from the swaybar. 
Will get there.



Starter motor
This is going to be interesting. 
As although the 3S flywheel works with the gearbox and crank okay once the PCD is embiggened. 
The ring gear diameter is a little smaller than the 4GR one. So this means the Mark X starter motor in its normal position wont work.
Then the 3S starter position wont work either, because it's normally tucked in on the side of the block up high. But now there's a vee in the way. 
So I still might need to look at rear mounting a starter.

Lots of problems to figure out. 
Sort of getting there but also feeling like I've hit a bunch of roadblocks at the moment. 
 

[Roman]

Not much progress on this as I've been full steam on house stuff, and just too exhausted to do anything car related. 
However I had a brief respite the other day so started stripping the motor down to try get the heads off. 
As the next tasks will be fitting stiffer valve springs, and pressing in some plugs for the direct injection ports.
It's amazing how much smaller it gets with the stuff off - all of the covers etc dont really contribute any meaningful weight.
So this picture here is a reasonably good representation of where the weight is distributed. Definitely a bit lower and further back than beams motor. 
So, although I'd prefer the car lost some weight from the motor swap instead. This is a reasonable consolation.




Something that is on my mind at the moment, that might screw my plans a bit. 
Is that all of the good things about this motor, are that its a big motor that's been downsized.
But there's one major disadvantage to how they've retained the big motor's geometry. 
The bore spacing is the same as the 2GR, and the valve spacing is the same - this means the 2GR cams will fit. 
This is great as without beefy cams, this project is dead in the water. 
But it makes for an interesting design limitation with the head. 

If we take a look at a 2GR head, with its 94mm bore. 
You can see that the distance between each pair of intake valves is reasonably spaced, to not be shrouded by the bore, and also not too close together either.
So, if you had a blank sheet of paper engine design this is what you'd do.



So that's great. But the 4GR motor is keeping that same centers between valves, with a bore that is 11mm smaller.
So they have no choice but to shrink the valve diameter to fit inside the bore, as they cant move the valves closer together.  
So there are these pissy little exhaust valves, and intake valves which are much more shrouded by the bore.
With a massive gap in the middle.


So, this might be a factor that limits its potential to make power at high rpm, even if the rest of the motor is technically capable. 
Will give everything a measure up once I've got the heads off. 
This isnt a deal breaker which will make me choose another engine, but its certainly not ideal either.
One potential upside is that these smaller valves will be a bit lighter, which might be helpful. But again, ideally would trade for larger valves that are closer together.

[Roman]

"Buy a newer motor" they said 
"It'll be fun" they said 

I'm still cleaning this up, its amazingly grotty on intake, combustion chamber, and the exhaust port.
The joys of direct injection! 
The pistons look okay though, MUCH less shit on them than the prius motor which ran the cooled EGR through it.

After seeing it in person I'm a little more optimistic about flowing some air through it though. 
There's some easy wins in the combustion chamber to deshroud the valves a bit. 
And the port angle on the intake side looks super sweet! 
Will take some better pics once I've got some kero and cleaned it up properly.