[mike Crawford]

I read where people buy dish pistons .. 18cc - 15cc for special purpose applications.
But I never read what the original chevy dish pistons were as far as cc's

I think there must be a difference between the new and old dish pistons or people would use the original ones .
I believe most motors from 71 on were dish . So why buy new dish pistons if there is piles out there already dish . Or the ones in the motor are dish already ...
I have a 67 327 that came from a school bus that has original dish pistons .
What cc they are I have no idea ..

[zildjian4life218]

Originally Posted by mike Crawford

I read where people buy dish pistons .. 18cc - 15cc for special purpose applications.
But I never read what the original chevy dish pistons were as far as cc's

I think there must be a difference between the new and old dish pistons or people would use the original ones .
I believe most motors from 71 on were dish . So why buy new dish pistons if there is piles out there already dish . Or the ones in the motor are dish already ...
I have a 67 327 that came from a school bus that has original dish pistons .
What cc they are I have no idea ..

On the inside of the piston skirt there should be a number. Find it on this site http://www.beckracing.com/page22.htm#SECT5

[my87Z]

Originally Posted by mike Crawford

I read where people buy dish pistons .. 18cc - 15cc for special purpose applications.
But I never read what the original chevy dish pistons were as far as cc's

I think there must be a difference between the new and old dish pistons or people would use the original ones .
I believe most motors from 71 on were dish . So why buy new dish pistons if there is piles out there already dish . Or the ones in the motor are dish already ...
I have a 67 327 that came from a school bus that has original dish pistons .
What cc they are I have no idea ..

the reason most people go with an aftermarkt dished pistons such as the KeithBlack hyper 18cc D cup or the 12cc dished pistons is for one because they are made with better metals than the original cast pistons, as well as they have a better crown design. the original GM dished pistons had a O shaped dish in them witch doesn't create any area on the piston crown for a quench pad, where as the newer style dished pistons are typically D cuped so that the flat area on the back side of the dish is used as a quench pad. this quench pad makes for much better combustion, less fuel is wasted therefor creating a more efficiant, more powerful engine. I have personally used the KeithBlack 18cc D dished piston in 2 different 383's of my own and another 383 that i built for a friends father. these 383's ranged from 420hp- up to 510hp. you just can't use a GM orignal cast aluminum O dished piston for these kind of motors. i would never use a O dished piston in any motor, ever, whether i was just building a mild 330hp engine or a lower compression 500hp engine.

many of the orignial GM cast aluminum O dished pistons were 22cc, if my memory serves me correct.

[mike Crawford]

Thanks for the reply ..
On another note then .. The original flat tops from 69-70 would also fall into that idea ..

I did rebuild a 70 four bolt main block and used original specs .
New cam but the same grind .. same pistons with new moly rings
Same heads but of course rebuilt them .
Works good for a every day driver

BUT I was working with about 260 house verus 500 ))

Never did any motors with dish and was just wondering why people bought new pistons .
Was thinking of doing something with the 67 327 ..
So just doing a little research.. First 327 I ever seen with dish pistons .
And was wondering what the cc would be .
So I think I better look at some new flat pistons.
Was hoping I could have used some low cc heads