Factory Honda Piston Guide

[96Clipse]

I'm wondering if anyone could maybe help me out with a question I've been milling around in my head for a little while but can't seem to find too much info on.
Does anyone know what the different compression ratios and factory casting/forging differences are between the different higher grade B-series pistons are? Namely the differences between P30, CTR, and ITR pistons?

The reason I ask is I'm trying to plan out an Ls/Vtec build that I want to have boosted, and I'm trying to find a suitable set of pistons, but don't want to settle for the 8psi limit of the stock Ls pistons because I'm looking to run around 10-12psi when all is said and done.

[tricura]

You are better off just doing a forged piston, the cast pistons are weak around the ring lands.

[The Alchemist]

really?

[tricura]

For every factory motor we have torn down that was boosted, they all have had cracked ring lands.

[Honduh]

I think this is what you are looking for: http://www.c-speedracing.com/howto/compcalc/compcalc.php Its the c-speed racing compression calculator.

Also, many people boost stock honda engines and they last a long time. Its true ring lands do crack sometimes but its usually due to poor tuning and how hard its beat on. I sat boost it till you blow it, then put some pistons/rods in it.

[OutToWinPAHC]

and sleeves

[Honduh]

and sleeves

Why? From what it sounds like he isn't trying to make more than 300whp. OEM sleeves can usually handle up to 500whp with a proper tune.

[OutToWinPAHC]

Its better to have and not need rather than need and not have

[Honduh]

Very true, I wish I would have had my block sleeved....but I have a spare to send out in case mine pops. But in this guys case I don't think it would be needed unless his goals grow.

[OutToWinPAHC]

They always grow... 200WHP then you want 400 then you want 800.... cars suck

[96Clipse]

Hey Honduh thanks for that link man that actually helps a lot but from the quick couple combos i looked at seems like all the stronger factory pistons don't really lend themselves to boost applications cuz most of them are in the 11:1+ range

And as for sleeves, there is no need, at most I'm looking for 300whp, but more realistically I'm looking for a peppy 200-250, because in a light car, thats more than enough fun for something daily. Also the whole setup will be built on a separate motor, so should it take a dump, a simple swap back to the previous motor will be no more than a few hour job one night at work.

I'm also a subscriber to the boost till you blow lifestyle that Honduh mentioned lol

[Honduh]

Yeah no problem man, I'm glad it helped. And yeah that is true that the factory vtec pistons are all kinda high compression. But there is a lot of guys running around on stock block ls/vtecs with head studs and arp rod bolts running 250-300hp on 7-10psi, depending on tune quality. I don't like to really go by a certain PSI # as a goal ever because it all really depends on the turbo.

[tricura]

If your pistons are fine now, then leave them in there til they break. Just tune off what you have and it will last for a little while. Your power goal is easily obtainable on a factory LS bottom end.

[96Clipse]

Yea I know that a psi number isn't a good goal because psi all depends on how well the engine flows etc etc, I just posted that up as a guide towards what kind of info I was looking for. And also the 10-12 number is what i've seen a few guys running on the very common T3/T04E setup that a lot of ls/v guys use, but none of them would give up the info on their pistons / comp. ratios (I think because they had no idea).

But if there are people making that kind of horsepower on the stock blocks with simple ARP upgrades, I may put off the bottom end build and focus more on head work.

Also, has anyone here dealt with Import DPS in philly? I'm looking to buy an exhaust from them and don't want to get shafted, because I know there are a lot of places in philly, especially north philly where dps is located that simply are chop shops.

[Honduh]

I've heard good stuff about Import DPS. They used to be a vendor on here. I THINK I bought my 1/2 rad from them......