Roman's 4GR V6 Carina discussion thread

[lowlancer]

Between this, custom 4age milled heads, Bugatti engine builds and mild boso mk1 pajeros, we've come a long way from the OS days of ex lancers with sohc 4g63 swaps or pinto powered mk2 escorts. 

 

Carry on.

[Roman]

For a while there I think there was a bit of a technological lull. 
Where it seemed like we never got any of the stuff that Back to the Future alluded to for the year 2020. 
No flying cars or hovering skate boards.
But the last few years truly has been an explosion of affordable and amazing technology at a consumer level. 
It's insane what is possible now, and awesome to see the variety of shenanigans on OS still going on! 

[Hyperblade]

RE Airbox, this is worth a read regarding expansion if you can fit it in the space you have

https://www.racetechmag.com/2017/08/willem-toet-explains-air-ducts/

Can't tell from the picture but I assume you are roughly keeping the same area from inlet to air box.

Looking awesome!

[GARDRB]

On 31/07/2026 at 23:26, Roman said:

I think I'll also scan my fairly pooey gearbox crossmember which needs spacers. Then remake it to the correct dimensions. 

I'm kinda abusing the quote system here, but I look forward to your organically generated 3d printed allow gearbag crossmember

 

[Roman]

2 hours ago, Hyperblade said:

RE Airbox, this is worth a read regarding expansion if you can fit it in the space you have

https://www.racetechmag.com/2017/08/willem-toet-explains-air-ducts/

Can't tell from the picture but I assume you are roughly keeping the same area from inlet to air box.

Looking awesome!

I remember you posting that up when I had the echo. 

The area from right at the nose of the car converges up to a pinch point of sorts then expands back out over the throttles.

But the idea is to use up all or nearly all of the space over top of the radiator and seal it off to the front.

But will just get a full side printed and see if it looks any good or weird IRL.
As its more of a visual thing than any science to it really.

[BiTurbo228]

Your leaking slave cylinder explaining why I won't touch concentric slaves with a barge pole. Pulling the engine to change a clutch slave? Sod that for a game of soldiers...

[yoeddynz]

But once they are sorted (ie use a new one just to be sure) they are pretty bloody good and very smooth.

Plus less clutter on outside of engine/box.

[Roman]

I think it cant be understated just how good it is, when you can buy a whole motor/gearbox/alternator/everything as a factory assembled package.
Simple things that you expect to just work, end up being a big pain when you have to bodge it all together.

Back in the day people used to be annoyed that SR20DET would get swapped into Toyotas and so on. 
But there wasnt really a toyota equivilent for a RWD car that was good and had good aftermarket support.
It just makes a heap of sense because you could get the whole damn thing, especially with factory turbo/manifolds/etc.
Just something simple like mounting the alternator onto the 1NZ ended up being a big headache. 
When you have multiple of these sort of things going on, its a big headache. 
Having to custom sort out things like clutch and gearbox arrangements are a potential cause of all sorts of annoying problems.
So I'd rather have a factory fork and slave cyl if it were possible here. 
As I can just be fairly sure that it's going to work. But bolting a disagreeable motor and gearbox together, have to roll the dice. haha

[BiTurbo228]

Yeah I think it's just my general and growing lifetime intolerance for removing other parts to get at the part I need. It narks me in a way that it probably shouldn't. To the point that I happily invest hours making little access hatches in my cars so I can get to bolts properly, even though I rarely get that time back in actually removing the part (probably, I haven't really counted, it's the principle of the thing).

And I've done my share of mashing the wrong bits into the wrong cars. Not quite to the level of you two, but hopefully getting there at some point. But it's not ignorance of those challenges driving it.

Call it a 'design philosophy'. I'd have quick-release pistons if I could.

[Roman]

The first car that I really worked on was an SW20 MR2. possibly one of the worst cars to start with haha.
What I learned from this car, is that trying to take any sort of shortcut is just absolutely punishing. 
Like, you might wrestle to remove a gearbox while leaving the motor in the car, then find out that you cant get the top bolt out anyway. So then you have to pull the whole lot out anyway, and you've wasted even more time and effort. 
Also, if something has gone wrong that was installed "on the bench" its unlikely that I'll be able to diagnose or repair nicely while everything is in a cramped space that's hard to see. 

So I will always opt to just take the whole lot out, and work on it in a clear space. 
Even if it takes a few hours longer, it saves about 5000 swear words and makes the whole process a bit less unenjoyable. 
Also this problem wasnt even coming from inside the bellhousing. I could very well have seen that the join was leaking, and nipped it up and then not seen the pinhole leak. 

"The long way is the easy way" is probably a summary of my experience and wrenching philosophy haha.

[BiTurbo228]

Yeah I fully get that and it's 100% reasonable.

Faced with the same 'MR2 bellhousing top bolt clearance issue' my response would be to holesaw an access hole into whatever was preventing me getting at the bolt (provided that was in any way practicable), so that next time I need to do it I can remove just the bit I need. It's not always possible, but wherever it is it happens.

Pinhole leak would have stumped me though, so there's definitely that. Be like Roman, people. It sounds like it works better.

And yeah, I cut my teeth on an Alfa 156 V6 and that engine is wedged in there. Funny how you can have such similar experiences and come to different conclusions!

And of course, there's a proportionality to things. I don't mind removing stuff that has no other practical place to live. Big engines need to go in small cars sometimes. This is the way. But some things are just stupid. Take the glow plug module on the BMW M57 engine in my Jag. It's tucked under the intake manifold, which is fine I suppose (other than that it's a fragile piece of electronics strapped to a big heat-and vibration generator so they die frequently...). It's 14 bolts, a clamp and a couple of sensor plugs. But then they put the damn thing slap bang underneath the coolant outflow from the engine so you really have to wrestle the thing out to avoid dropping the coolant. 8" of clear space ahead of it, 4" behind it. If it was 3" in either direction the job would be a breeze. Why?! So one job on the list is to sort that. Either by relocating it to the engine bay, or just tweaking the wiring so it can be mounted literally anywhere else.

Stuff like that has kinda prejudiced me I suppose.