What dish piston do i need?

[recordbreaker5]

I am getting my block rebuilt at the moment but what I'm looking for before everything is bought for the rebuild, i'm trying to figure out what size dish i need to get. I would like a CR around 9:1. I have 53cc CNC heads. Would I need a 14cc dish for a good CR? Any ideas or recommendations are appreciated. I have a F1 on the car, so hp output is 700hp+ on 15-17lbs. Also, recommended brand of pistons for this setup. thanks for the input!

 

[JeremyH]

I run 15cc diamond pistons 9.1:1 compression.


15-17psi will get you to around 600rwhp on 9:1 setup, what cams/manifold do you have to go with those heads?

 

[recordbreaker5]

comp cams custom grind blower cams, FRPP intake. I just got off the phone with Diamond and with my 53cc heads w/ a F1, with stoke bore and stroke, that a 6cc dish would be optimal for 9.3:1/9.4:1 (depending on thickness of head gaskets which are cometic but don't know if they are a 30 or 40). he was speaking so fast to me that I couldn't comprehend all the shit he was saying, but caught bits and pieces. lol

 

[Marc s]

Here is the calculator I used to determine which pistons to buy.

Based on the info you gave and assuming your pistons are .010 in the hole. A 6cc dish comes out to 9.53:1. I have a compressed FRPP gasket which measures .041.

http://www.wallaceracing.com/cr_test2.php

 

[recordbreaker5]

Here is the calculator I used to determine which pistons to buy.

Based on the info you gave and assuming your pistons are .010 in the hole. A 6cc dish comes out to 9.53:1. I have a compressed FRPP gasket which measures .041.

http://www.wallaceracing.com/cr_test2.php

ok, i messed up on my previous post. guy at diamond said 9.5:1 on .30 and 9.4:1 on a .40 When I told him I had a F1 centri, he recommended these CR's which would allow me to spool up well. With a TS/roots, he recommended a lower CR below 9. I am guessing he was referring to really high hp cars that dealt mostly with racing.

 

[Marc s]

I too agree with 9.5:1 or better with the Procharger. One thing to keep in mind when you are using the compression calculator. Stock pistons have a compression height of 1.22". Some aftemarket pistons have a compression height of 1.21". This puts the piston .010 further down in the bore. Also, on aftermarket pistons, the top ring is lower which allows for a thicker ring land. The lowered top ring will add to the chamber volume. I purchased pistons for my build that were advertised at 9.4:1. After I CC'd everthing, these pistons put my compression at 8.63:1. My advice is to measure everything and don't trust the advertised compression ratio. Because of the changes in ring location, compression height, and gasket thickness, I ended up with a -5cc dish piston which put my compression at 9.70:1

 

[JeremyH]

ok, i messed up on my previous post. guy at diamond said 9.5:1 on .30 and 9.4:1 on a .40 When I told him I had a F1 centri, he recommended these CR's which would allow me to spool up well. With a TS/roots, he recommended a lower CR below 9. I am guessing he was referring to really high hp cars that dealt mostly with racing.

Procharges dont spool! lol

I agree i would go for 9.4-9.5 with a centri.

Is it a stroker motor?

If your shooting for closer to 700rwhp plan on 20psi btw.

 

[jtscuba02]

Thanks for the calculator link. I have been looking for one like the Harley one from BigBoyz cycles.

 

[recordbreaker5]

Procharges dont spool! lol

I agree i would go for 9.4-9.5 with a centri.

Is it a stroker motor?

If your shooting for closer to 700rwhp plan on 20psi btw.

Well I'm not saying they spool like a turbo but still lack the low end torque like a turbo because they have to build boost at a higher rpm vice a TS. So its working like a turbo but just parasitic. The motor is with Mark at Panhandle Performance in FL. He is doing the motor. I will have a talk with him and make sure the CR stays around that 9.5:1 area. It's not a stroker though I wish I would have stroked it, but stock bore and stroke. I know it capable of over 700rwhp no problem. If it doesn't get there on a 4.75 pulley, my 3.7 should put it beyond.