RL & TL pistons used in 3.5 builds

[IDon'tKnow]

I've brought this up in several threads and haven't yet received a legitimate answer so I thought I would go ahead and start a thread about it.

The orientation of the piston in the bore @ TDC doesn't change between the J32A2 and the J35A3 and both heads use 36mm valves. Why then does everyone out there seem to think that the RL pistons are necessary (because of valve clearance) when bumping the J32 up to a 3.5? Or, rather, if you know for a fact that the RL pistons are necessary, please explain why.

[paton]

Are you suggesting that only a crank swap would be required?

I have often asked myself the same question you are asking now...

From what I understand, if you want to upgrade to 3.5L displacement, you need an Odyssey crank, and RL pistons (for whatever reason) but if you just used the Odyssey crank, and reused the pistons you already had, would this not work?

It's just the crank that changes the displacement, right?

[IDon'tKnow]

The only parts neccessary are the Crank and Rods - I jumped over to the "Other Forum" and started an account so I could consult "the godfather" about it.

The RL pistons are more popular because they are factory forged. Apparently the dome hieght is higher - the chamber is also a different shape in a J35A3. All of that is heresay, but I think the guy I talked to knew what he was talking about.

So: the CL and TL pistons will both work fine; they just aren't as light as the RL pistons and are perhaps slightly less durable.

[paton]

Aha... the godfather you say. I believe I know who you speak of sir, as well as the domain mentioned.

I just read as well that the compression is slightly higher when using RL pistons. So basically the only reason you would switch to the RL units is for FI? For all of the NA guys the pistons you already have are just fine.