patSS/00

iTrader: (6)

Does anyone know the exact compression height of stock 00 LS1 pistions? Supposedly they were made by Mahle, but their piston catalog has some contradictory information. The CH number should be either 1.33" or 1.34". I'm trying to find cast flat top replacements, not many choices and they're all 1.328" CH, which Mahle says is a reduced compression piston.

G Atsma

I have a feeling the 1.33 number you quote above is just 1.328 rounded upwards.

patSS/00

iTrader: (6)

Sure, but the question is whether 1.34 is what the stock ones were, which means all the available replacements are lowering compression slightly, which is the opposite of what I'm aiming for.

patSS/00

iTrader: (6)

Also when I plug in the numbers, block height (9.24) - (stroke/2 + rod length) + deck clearance (.006-.008), I get about 1.34" for compression height, so I think that's right.

The difference in compression between 1.33 and 1.34 CH is not small, like 10.2 vs 10.5 with my numbers.

G Atsma

Yeah .010 is a BIG difference, as you said. Does Mahle have a tech line to call?
Besides all that, give a call to WS6store. If anyone would have the piston you need, they will and at good prices accompanied by great service.

patSS/00

iTrader: (6)

I had the machine shop which has my block measure my old piston, confirms it is 1.341" CH. These are the original stock pistons from 2000.

tech@WS6store

iTrader: (2)

They have an FM on the inside i believe so thats fed mogul not mahle.
Ive measured 1.333 to 1.331