I took a 99 ld9 block and used wiesco forged pistons and a stock felpro 2.4 gasket and a 086 head. What would my compression be? Is there and difference between using a 99 block and a pre 99 block?
are the pistons dished? flat top? domed?
are they larger diameter than stock?
Trailer Queen corvette wanna-be with 40 coats of wax and powdercoating that soaks in.
are you talking compression ratio or compression psi? i don't believe a larger diameter would affect compression ratio, but it would change compression psi, and piston top will affect both. Also if your talking comp. ratio, combustion chamber size will need to be takin into account
horsepower is the force that determines at what speed you hit the wall, torque is the force that determines how far you take the wall with you after you hit it.
The difference in blocks is the knock sensor hole but thats an easy fix. With the 086 stock style wiesco pistons would yield 11.37-1 compression, 9-1s would end up being roughly 10.5-1. The bore size affects the compression slightly but those are rough estimates.
I used 9-1 wisco pistons for the 2.4. then used the smaller cc 086 head. Factory forged wiesco pistons
no factory j-body came with wiseco pistons stock, sorry.
so the pistons are dished then?
Trailer Queen corvette wanna-be with 40 coats of wax and powdercoating that soaks in.
They are the 9-1 wiesco pistons. Not customs
ryan scott wrote:They are the 9-1 wiesco pistons. Not customs
Then not taking into account overbore, head surfacing, and head gasket thicknes you have rougly 10.5-1 compression.
10.7:1 static CR with 9:1 pistons...this has been discussed a number of times in the past.
I have no signiture
what are '9:1' pistons though?
there are only three pistons i know of... dished, flat top, domed.
which is it?
Trailer Queen corvette wanna-be with 40 coats of wax and powdercoating that soaks in.
They're dished Brad.
9:1 refers to 9:1 SCR with the stock 60cc (or is it 62cc...my memory fails me) ld9 head. I have done the calculation at least 30 times before, and so have others (e.g. Gilles)...and have no desire to do it again.
With the stock .043" headgasket, the SCR = 10.7. With a more aggressive overbore, it will be slightly higher.
I have no signiture
Wiesco's dished pistons are rated 9-1. other lower ratios are available but the 9-1 are the norm. Atleast from what I can find. Those are the ones I have in the engine I bought from Kris Bloom. When I plugged in my numbers with a felpro head gasket thickness I got 10.5ish-1 with the 086 head. Right now I cant remember how many cc's are in the dish of the 9-1 pistons.
Thanks for the info. Mine are indeed dished so thus 9-1. I have only seen these advertised on web sites. If I wanted more compression where would I buy different pistons?
Stock conpression pistons will give you 11.37-1
Can you by stock compression forged pistons or just buy as stock piston from any general auto parts store?
I also thought 9-1 was stock? I am confused. I thought my 9-1 wiesco pistons was stock compression
96-98 had 9.5-1 and 99-02 had 9.7-1 stock. Importperformanceparts has the stock compression forged pistons. I think carrcustoms and turbotech racing do too.
what if they have 97 flats and bore in .030??? what would the compression be ????
It would be slightly higher but only by like .2 or so.
