Turbo LS1 SS

iTrader: (7)

Hey guys,

I'm posting this here considering you all have more experience looking specifically at boost pistons. I'm building a 370", and I'm looking to avoid going down the custom piston route again

This is what im looking for:

4.030" bore
6.125" rod
3.622" stroke
~19cc dish
.927 pin
prefer a deep top ring down
as close to even deck as possible

i found a wiseco 25cc, and a diamond 15cc. i would like something in between.

ready, GO!

thanks,
bill

ninetres

iTrader: (35)

If you are THAT specific on your rotating assembly......it seems you HAVE to go custom.

I know mahle makes a -16 and a -20 but I don't know the rest of the specs.

DanZ28

iTrader: (5)

How do you end up determining your CR on all these pistons without the piston deck height? I'm looking for the same size FI piston as you but not sure how you find the deck height on them? What CR are shooting for, 8.4 area?

Dan

Turbo LS1 SS

iTrader: (7)

yes im shooting for the 8.4 area.

i know the diamonds are .010" out of the hole, and i dont remember what the wisecos came in at, but when i calculated them, they were 8.87:1 and 8.13:1 respectively. my buddy was going to call mahle and check on these because their online catalog is a little outdated....

the problem is my last set were custom from diamond..... completely custom, not a shelf piston that was massaged a little bit.... thats very expensive, and you can't buy just one replacement, you have to buy 4 MINIMUM at a time, which is about the cost of 8 shelf pistons. im just checking out all my options....and contemplating what i want to do

DanZ28

iTrader: (5)

Looked up the diamonds for my set, I'm going with a 408" though. Diamond has what they call an "inboard forging race-dish" piston. I would need a -28cc piston for an 8.5 CR. They are also a bit lighter and have a top ring down of .300. They have a 0" deck too. Only bad part is they are not a stocked piston if your in a hurry to get them. They also don't list them in a 3.622 stroke or smaller than -28cc.

I'm going to keep looking but those look pretty good for me.

Dan

NA$TY-TA

iTrader: (21)

Ya might have to order a set if ya want in between what most have a s shelf pistons...
Thats the only way i know to keep the $$$$ down... as we both know a custom piston is about $1,000

Turbo LS1 SS

iTrader: (7)

the difference is a larger CI engine requires more dish to achieve the same SCR. 28cc dish on a 370 would be in the 7s with my 72cc heads. i could boost my scr by opting for .040 cometics over .051" (8.2x, where i was at before), but my friend is telling me it won't clear the piston. which i dont understand/agree with, but we will find out.

i could get shelf diamands and cut them down for like another $100 or so, i just need to figure out my future plans. im thinking about some twins

DanZ28

iTrader: (5)

Yeah, I started out with a 370, now looking at a 408, but I'm tempted to get the LSx block and do a 427 .

I'm not sure either about the PTV issue, seems like you would have plenty of room with a big dish piston and 72cc heads. I runa .027" gasket now with -2cc reliefs and 62cc heads.

Anyway, hope you get it figured out, post up here with what you find as it's always good info to have around when the search button gets used..

Dan

Turbo LS1 SS

iTrader: (7)

my buddy just got his Mahle catalog. calling them was useless as most of the company is OE, and they didn't know what we were talking about

there is a 4.020" 20cc piston that will work out for 8.56:1. it is the power pak piston in 4032. no i need to decide between the 4032 mahles for 8.5:1 or the 2816 diamonds for 8.6:1 with .060" gaskets

i like W2W's take on the 4032, and we've ran a 4032 with luck in a slightly less HP procharged car, but everyone elses comments kind of scare me. its tough to filter who knows what they are talking about, and who is trying to sound like they know obviously W2W knows. we are also currently running diamonds in a few engines and they are nice units