Piston perfromance

Dwight Southerland · 09-02-2013, 09:17 AM

Joe,
Assuming comparable compression ratio, there are instances in SBC Super Stock combinations where a properly shaped dish has a alight advantage over a similar combination with a flat top piston with valve reliefs. There are lots of other factors in that equation though, not just the dish vs. flat top comparison. That being said, the shape of the dish is critical for the advantage. For Stock combinations, the factory dish shape is a disadvantage in every situation I have seen.

carl hinkson · 09-02-2013, 10:52 AM

Same compression and reverse dome VS flat top the reverse dome whens every time.

Joe DeMarzo · 09-02-2013, 01:29 PM

Dwight, thank you for the insights on the factory stock dish shape ... there are some 305 combo's that are identical except the piston. The flat top is rated 20 HP more, and killer fast. Was thinking why not run the dish piston -260lbs.

Lee Valentine · 09-02-2013, 01:41 PM

Joe ,I believe there are other differences I think in cameros flat top engines are big cam dish are small cam.

Joe DeMarzo · 09-02-2013, 01:45 PM

Lee, they are not both Camaro's, one is a Camaro and the other is a different body style.

Dwight Southerland · 09-02-2013, 04:06 PM

Joe -

Are you talking Stock or SS? In either case, the flat top engine and the later shallow dish piston engines are at least a point more compression than the early dished piston engines, so its not apples to apples.

Joe DeMarzo · 09-02-2013, 04:21 PM

Dwight, now we are getting somewhere. Strictly stock. Would the flat top with notches be worth carrying the extra 260 lbs? Rough HP number on a dyno, 10, 15, 20 HP less from the dish piston?

The flat with notches is a better piston but would it worth the weight?

I am asking a lot without much info, lol that why class racers are the best!

CFMCNC · 09-03-2013, 12:40 AM

In most cases a spherical dish will make the most power,However there are a lot of variables.Bill C.

09-02-2013, 09:17 AM	#1
Dwight Southerland VIP Member Join Date: Dec 2001 Location: Arkansas - In the middle of everything. Posts: 2,002 Likes: 64 Liked 783 Times in 195 Posts	Re: Piston perfromance Joe, Assuming comparable compression ratio, there are instances in SBC Super Stock combinations where a properly shaped dish has a alight advantage over a similar combination with a flat top piston with valve reliefs. There are lots of other factors in that equation though, not just the dish vs. flat top comparison. That being said, the shape of the dish is critical for the advantage. For Stock combinations, the factory dish shape is a disadvantage in every situation I have seen.

09-02-2013, 10:52 AM	#2
carl hinkson Member Join Date: Feb 2007 Location: NORTHEAST Posts: 287 Likes: 1 Liked 18 Times in 10 Posts	Re: Piston perfromance Same compression and reverse dome VS flat top the reverse dome whens every time.

09-02-2013, 01:29 PM	#3
Joe DeMarzo Senior Member Join Date: Oct 2002 Location: Mahopac, NY Posts: 668 Likes: 49 Liked 121 Times in 11 Posts	Re: Piston perfromance Dwight, thank you for the insights on the factory stock dish shape ... there are some 305 combo's that are identical except the piston. The flat top is rated 20 HP more, and killer fast. Was thinking why not run the dish piston -260lbs. __________________ Joe DeMarzo 1317 STK

09-02-2013, 01:41 PM	#4
Lee Valentine Senior Member Join Date: May 2004 Location: Brookfield, CT Posts: 708 Likes: 13 Liked 319 Times in 68 Posts	Re: Piston perfromance Joe ,I believe there are other differences I think in cameros flat top engines are big cam dish are small cam. __________________ Lee Valentine 1661 STK

09-02-2013, 01:45 PM	#5
Joe DeMarzo Senior Member Join Date: Oct 2002 Location: Mahopac, NY Posts: 668 Likes: 49 Liked 121 Times in 11 Posts	Re: Piston perfromance Lee, they are not both Camaro's, one is a Camaro and the other is a different body style. __________________ Joe DeMarzo 1317 STK

09-02-2013, 04:06 PM	#6
Dwight Southerland VIP Member Join Date: Dec 2001 Location: Arkansas - In the middle of everything. Posts: 2,002 Likes: 64 Liked 783 Times in 195 Posts	Re: Piston perfromance Joe - Are you talking Stock or SS? In either case, the flat top engine and the later shallow dish piston engines are at least a point more compression than the early dished piston engines, so its not apples to apples.

09-02-2013, 04:21 PM	#7
Joe DeMarzo Senior Member Join Date: Oct 2002 Location: Mahopac, NY Posts: 668 Likes: 49 Liked 121 Times in 11 Posts	Re: Piston perfromance Dwight, now we are getting somewhere. Strictly stock. Would the flat top with notches be worth carrying the extra 260 lbs? Rough HP number on a dyno, 10, 15, 20 HP less from the dish piston? The flat with notches is a better piston but would it worth the weight? I am asking a lot without much info, lol that why class racers are the best! __________________ Joe DeMarzo 1317 STK

09-03-2013, 12:40 AM	#8
CFMCNC Junior Member Join Date: Apr 2012 Location: Somwhere in NJ Posts: 72 Likes: 4 Liked 3 Times in 3 Posts	Re: Piston perfromance In most cases a spherical dish will make the most power,However there are a lot of variables.Bill C.