Engine compatability

MATT-S

New member
Hi chaps, Iv'e just bought a rev 3 mr2 turbo bottom end, ie block pistons rods crank oil pan etc etc. i'm hoping to fit it to one of my st185's before long, so i just need to know if,

a. the block will fit my car, as in sensors and alternator brackets etc

b. if a 185 head will fit the rev 3 block, if so do i use a 185 hg or a 205 hg

I'm planning on running it using all 185 ancillaries including afm.

Cheers

Matt
 

jprine01

New member
I think it should be fine, i would think 185 headgasket, 205 timing belt. May be some other little things, like turbo support mounts not being in the same spot so they wont work etc. But yea it will work.
 

OlyST185

Active member
the headgasket is the same, the timing belt of the 3rd gen has 2 more teeth if my memory serve me well.
theres no problem using a 2nd gen head as but youll have the use the 2nd gen intake and fuel rail.
 

MATT-S

New member
Thanks for the replies, I thought that there was a slight differance with the oilways or something on the hg? any thoughts? the thing with the timing belt being 2 teeth longer, is this due to tensioner position? i'm not going to have my timing out or anything like that?
Thanks for your help guys.

Matt
 

alltracman78

Active member
Not sure on the belt thing, but supposedly the g2 head/manifolds are better [unmodded] for total flow.
That's what I would stick with.
If the g3 tensioner is what calls for the g3 belt, maybe you can use the g2 tensioner and belt instead. Would be much easier to find.
 

k_trac

New member
I'd get my hands on a gen3 head as well, that way you can get the bigger cams, single runner intake manifold, and newer head design.

Of course I havent done a side by side comparison so I cant say defiently which one is better, but Im going full gen3 on my car.

also, you wouldnt have to worry so much about matching up parts if it were all just 100% gen3

GO TO THIS LINK, IT EXPLAINS EVERYTHING FOR YOU!

http://homepage.ntlworld.com/bowen67/
 

jprine01

New member
THe headgaskets are different, but if you get a HKS it works on both. If you go with toyota use the 185 or the TTE metal 185 gasket. The coolant ports are different, a 3rd gen gasket may block some cooling holes to the head but I dont have a 3rd gen gasket anymore to test on my 2nd gen head. The oil passages are the same no problem there.

The extra timing belt length may be because of the different oil pump?? Not sure but i know its in the bottom end, so 3rd gen bottom end 3rd gen timing belt.

It has been said/"proven with rigs" a 2nd gen head has a higher velocity ports, but this was tested without the 2nd gen intake manifold. So a 2nd gen head with a aftermarket intake manifold would be best option in my opinion. (I have a 3rd gen head/stock intake/throttlebody etc) You will need to use the 2nd gen fuel rail with your 2nd gen head (not as good as 3rd gen) so you may need to upgrade that if your going with large injectors.

Your timing will be fine, the 3rd gen head/cam gears are the same as the 2nd gen no problems there.

Cams are not all that much bigger, aftermarket cams would be allot better.
 

k_trac

New member
Dont forget about the gen3's bigger throttle body

Does the gen3 have the valve bucket shims like the gen2?
 

jprine01

New member
gen3 has shims**, but they sit in a a resessed hole in on top of the valve spring retainer area, but under the buckets. (2nd gen is over bucket) The shims are like half the size in diameter as the 2nd gen, and cant really fly out.

**edited

You could compare them to a watch battery, where the 2nd gen shims are more like a quarter.
 
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