legacycentral bbs

hi all,

ive got a question, my friend is giving me some low compression
turbo pistons and was wondering if they will fit my n/a conecting rods.

and how long would it take to install them?

any one?

You might see if you can edit the subject line to get a better response. "my car" is vague.

Why do you want to lower the compression? Are you planning to put a turbo on it?

ok ill change the heading. thanks for the heads up


yes im going to be turbo charging my n/a motor and want the turbo pistions for lower compresion.
i just hope they will fit/ mate up with my n/a connecting rods.

Are they "A", "B", or "C" size pistons?

Look on the top of your block. There is not quite an imprint, but kinda like writing, that will say something like this....

B C
B B

This means you have three "B" size pistons, and one "C" size piston.

Does this matter? I have not a clue. But I suspect it does.....

Somebody PLEASE correct me if I am wrong!!!

not sure but I am going out on a limb to say that it does matter. guessing its to account for different tolerances from the boring process.???

yup, Doug is right on, you need the pistons that are sized properly for your bore or else you won't have proper piston/bore clearance. You could fit a smaller piston in, but it would clatter and likely burn oil especaily on cold startup. You can't run a piston that's too big, even though it will likely fit cold it may sieze when hot or at least drag.

C is the smallest bore and A is the largest bore. You do need to match them. IIRC, the difference in bore from one letter to another is .010 mm. You can punch out your block when you hone it for the new pistons and rings (you are using fresh rings, right?). But if you bores are bigger than the turbo pistons you are adding, you are out of luck.

Post up what your block is and what the turbo block is, and I will tell you if you can make it work, if the above is at all confusing to you...

BTW, an easier approach would be to get some DOHC Ej25 heads and manifold and bolt them to your Ej22E bottom end...

where on the block will i find these letters?

Top center. Underneath the water crossover tube, slightly infront if you are lucky.

Since it is somewhat on subject. Matt what are the letters on your RS-RA?
Mine are all B. I was curious if this was due to a more controlled manufacturing process, i.e STi.

IIRC,
I've got 3B's and an A, but I would have to go look...