Anyone sell pistons here?

I had a cam bearing failure had to pull the motor. Figured while I have it out I could change my pistons for more compression instead of milling the 317 heads or finding a set of 243/799's.

I went the old school method and the motor sucks out of boost its currently a 8.9 or 9.1 I want to be more in the 9.8:1 or 10. with good fuel.

My rods are Callies 6.100" H-beam floating .945 small end not .943.

Correct me if I'm wrong but this is what I gathered from some math.


Cylinder Head Volume: 71.06cc

ls9 Head Gasket: Compressed: .055"

Stroke: 3.622

New Piston CH: 1.326

New Piston Bore: 4.005


.......................................Rod: 6.100
.............................Half Stroke: 1.811
....Piston Compression Height: + 1.326
...........Total Assembly Height. = 9.237

.............Total Assembly Height: 9.237
................Block Deck Height: - 9.240
..........................................= 0.003

Deck Clearance comes out to be .003?



This is based off of a 2cc Flat Top Piston from Summit Racing. Summit Part # 3269454005-2


If my calculations are right it will give me a 9.79:1 Compression Ratio? I'm using this for my Compression Calculator: https://butlerperformance.com/n-1287...alculator.html


My issue is they're out of stock and I'm trying to find something similar.


Please let me know if this is wrong.

Thanks.

 

use more boost?

 

Summit Racing and RPM Speed A.K.A. WS6 Store.

Both Sell pistons in various flavors for your needs.

 

Regarding our SUM-3269454005-2 pistons. We checked into these and they are on backorder to us from our supplier. Our supplier has added shifts and has been working around the clock to try and keep up with demand. We hope to have a stocking order of these pistons in by the end of March.

Your calculations are correct with .003" being the deck clearance. The compression ratio would be 9.81:1 with 317 heads that are 71cc even. Quench would be .058". That is up there and wouldn't be optimal for fending off detonation. Going with a .040" head gasket would help and bring quench down to .043". That would also bump compression up to 10.14:1 which is fine for use with boost and 93 fuel.





We looked for a substitute piston. The closest we could find is the Mahle MLE-930217705 PowerPak piston and ring set. These are a 4cc flat top. They have a 1.340" compression height which would put the piston .011" out of the hole. This would put you at 9.9:1 compression. Quench would be .044" with your .055" gaskets which is good. This should allow sufficient PTV clearance pending cam specs.

These aren't in stock either. We checked with Mahle for availability. Mahle said if ordered today you could expect them to ship by the end of February.



Sorry about not having a flat top piston in stock for you. Hopefully, you find the other info helpful and useful.