Hi guys

I've done some research and can't find a solid answer this asking here.

Do the 2GR and 3GR heads have different combustion chamber displacements or are they the same and only bore is different on both engines?

I can't find a 2GR head that I can compare my 3GR head with hands-on thus I'm asking, I know the 2GR has both port and direct injection but apart from that, are the valves and combustion chambers different as well?

 

https://toyota-club.net/files/faq/13...engine_eng.htm
Different bore and stroke.

 

The stroke us same at 83 for both 2GR and 3GR.

The bore is different, are the valves different too?

 

Oh wow, I can't read

At any rate, I don't see the part number for the 2GR valves on any 3GR-equipped cars. They do appear on 1GR/2GR-FE/(1-3)UR-(FE/FSE)/2UR-FSE, interestingly enough.

What are you trying to do?

 

I've got a spare 3GR motor laying around and a set of 2GR pistons with their rods.

I was wondering if I can resleeve the 3GR block to receive the 2GR pistons, assemble the engine with 3GR heads

So it'll be a 3GR with 2GR bore only, no twelve injectors.

I don't think people have done this, but I'm pretty sure if it's mechanically possible, the 3GR stock ecu can easily run this setup without major leaning out issues

Only problem is, there's no writeups on this and I'm willing to take the risk for trial and error.

I was asking if the 3GR heads have similar volume to 2GR heads because if not, then i'll have to use the 2GR headgasket on this setup, if anyone can shed light on this and guide me, it'd be nice

 

Car in question is my Toyota MarkX

These are basically almost the same as a GS300 but lighter and RHD.

I chose the GS forums because the X also uses the 3GR-FSE motors,same suspension, same transmission. Mechanically identical cars.

 

Don't think I've seen a build where a head for a different bore size than the block's liners was fitted. Are you sure you're not confusing bore (cylinder diameter) with stroke (piston travel)?

On another note, RHD country? I envy you for being able to properly drive all those JDM-specific sedans/coupes >_<

 

Haha yes sir, we've got all Jap imports here more than domestic ones but import laws are strict now.

Im not confusing bore with stroke.
I mean, for example for some reason I use 3GR heads on a 2GR block, the 2GR bore is 93mm
The combustion chamber diameter of the 3GR heads will be according to the 87.5mm 3GR bore no?

 

For reference, here you go, the space highlighted is what Im inquiring about, this lines up with the 'bore' of the cylinder block
These would be different for 3GR and 2GR right?

This is from @KIS350's thread.

@2013FSport bro any input on this?

 

Did some research on other forums and apparently this is a popular mod among big block american muscles. People bore their head chambers to match oversized bores of cylinders.

Found a video of a Honda B20/B16 setup, the B16 comes with 81mm bore, the B20 with 84mm bore, so they bore out the combustion chamber to match the 84mm bore:
This is done to reduce hotspots and prevent pinging.

I'll be doing this to my 3GR heads, resleeving the 3GR block to 93mm and use the 2GR pistons.
Positive and negative input is welcome

 

For some reason this whole time I was wondering how you were going to adapt a 3GR head to fit a 2GR block (oil/water passages, etc), even though it was obvious from the start that it wasn't the case... fooled myself there big time.

Input...
Check the pistons for clearance with the valves. Some kind of dummy fit over the head or something... dunno. This sounds like the biggest risk - if you sleeve the block and the pistons end up hitting the valves... I guess the only option would be custom pistons.
Other than that, check if you can just swap a 2gr-fse, even though this is a first gen mark x. Better in just about every way - dual injection (valves are kept clean), no active intake elements (ACIS/swirl flaps), fuel economy should be pretty much the same, all kinds of aftermarket goodies to make it fly.

 

Are the 3GR and 2GR oil/water passages way off? I thought they'd be very similar and only the bore diameters were different.

Haven't gotten hold of both gaskets so I could compare them hands on

 

Here's what I've found, both the 2GR and 3GR head/blocks, I dont see many drastic differences in the passages, could be wrong

2GR:





3GR:

 

Contact @PAVGR PAVGR, he did some kind of 3GR head swap and knows more than myself.

 

There are differences that's the reason I swapped the hole engine.The electronics are the same.I swapped the engine and everything worked fine.Two more friends of mine did this swap also without the supercharger.The gains are 30 hp but there s power from 3000RPMs instead of 5000 of the 4GR