well i got a nasty surprise when i pulled my bottom end apart thinking i was just going to need a crank and rod and be back on the road. 3 out of the 4 pistons are toast. what p2w would you guys recommend for a 500 whp car that sees mostly street time? will probably have to go to 82mm, not that its that big of an issue, just sucks ordering new pistons and having to get machine work done again. Here's what 3/4 of them looked like on the intake side only.

 

ahh yes i did that on the dyno once. a .020 over should clean it up fine. the ptw depends on the piston material, fuel used etc. ive found that more than once the manufacturer ptw recommendations are a bit too tight.

id say it should range from .0035 to about .005, with .004ish probably being a good bet.

what were the previous ptw and what pistons were those. are you running that 500 hp on pump gas?

 

not sure what previous P2W was as i didnt assemble the engine. fuel is e85 and the pistons were JE

 

.004" is what I've used for my builds.

 

i went with .0045 cp pistons. im at around 530wheel. but I don't use e85 so .004 should be good for you

 

yea thats a good setting for cp's they seem to like to expand a lot. i had ptw contact on cps at .0035 (supposedly) .im putting my motor together next week and its coated cp's at about .0043.


op- to do that on e85 your previous settings must have been crazy tight. ive personally never used e85 but i know it runs much cooler so you could probably take .0005-.001 off your total tolerance ptw. ill let other e85 users chime in again since im not experienced personally in it

 

 

not sure what the point of that post was. he asked what the p2w was before and what pistons. i answered. new pistons will probably be wiseco, still undecided

 

Wow, it looks as if you only had .0005" clearance! Unless it ran lean for a long 5th gear pull!
Anyways, any reputable forged pistons with 0.002-0.003 ptw will safely work with E85.

 

Ok so I got another surprise. Previous owner told me it was stock bore, but it's really 84. Will I be ok at 84.25? It's got GE sleeves

 

Your machinist will know what clearance is best.

 

I'd rather have the clearances be to my liking, not many shops here that I trust with Hondas. Anyone see a problem with the bore being 84.25 on a boosted setup?

 

thanks for sharing.

I just assembled a short block for my buddy, and it was .003 - .0035", so now its something to think about. I have a feeling this would be okay, but personally, I would run it looser.

I went with .0045 with my wisecos, shootin for 500whp.

 

I'm going to 84.5 on mines you should be okay

 

what? hes talking about going to 82mm. not 84.5mm

op, sleeved block?

 

Yes. Golden eagle sleeves. Old Pistons were actually 84mm instead of 81 like I was told so it will have to go to 84.25

 

He clearly said 84.25 maybe you should read before correcting someone

 

original post said he was going to 82mm.. then later says its different bore.
how often do people actually not know what bore they are? rarely.

 

I didn't because I was told it was still factory bore when I bought the bottom end a few years ago. Didn't check until now, my fault for assuming though.