4A-GE engine mix - question

[oldeskewltoy]

A bit of research will help you quite a bit. First, have you seen the largest MR2 forum? http://www.mr2oc.com/

Besides that MR2 site, there is also http://www.club4ag.com.


Ivan141 is correct, parts of Europe got the 10 to 1 pistons. You'll know by if the car was originally equipped with a catalyst. No cat - 10 to 1, cat - 9.4 to 1. France required the cat, so they got the 9.4 to 1 engines


You need to decide WHAT you want, and then build it. It is easy to get diverted from your goals, so *IF* you do your research first, you will spend less, and enjoy it more.

A smallport head will make more torque EARLIER in the power band. That means equal mods, the smallport will be quicker in the first 60', then a largeport.


Finding a "good used engine" is rare these days. I recommend you build it from the ground up, that way you KNOW everything about it

Maren Wrote:I know I will have to shave the head and install a lower head gasket anyway as due to my work in the combustion chamber the capacity increased.

How much has the chambers been increased? I've done a LOT of 4AG head porting - http://www.aeu86.org/viewtopic/ost-porti...s/t/10896/




Depending on how careful you were, the chambers may only be 1cc larger (37cc, instead of 36cc) That 1cc enlargement only needs a .25mm cut on the head to get the chamber back close to stock, so a .25mm cut off the block(makes a perfect mounting surface) will give you a little extra compression - total with 37cc head and block cuts and using a "stock" 10 to 1 piston = about 10.3 to one when finished.