Posted By: Blucuda413
Minimum Compression Heigth?? - 01/08/09 06:12 PM
What is the minimum CH in a smallblock which would keep the rings out of the pinhole???
Minimum Compression Heigth??
Posted By: S/ST 3040
Re: Minimum Compression Heigth?? - 01/08/09 06:17 PM
The method Diamond uses, around 1.325" but, you can stack the rings tighter
and go with less. That's just their preference on the ring spacing.
Edit: That was using 1/16 x 1/16 x 3/16 ring pack.
and go with less. That's just their preference on the ring spacing.
Edit: That was using 1/16 x 1/16 x 3/16 ring pack.
Posted By: Blucuda413
Re: Minimum Compression Heigth?? - 01/08/09 06:20 PM
My current configuration has a 1.21 with custom pistons. I'm looking at a combo which would only be a .975. Is this way too short????
Posted By: S/ST 3040
Re: Minimum Compression Heigth?? - 01/08/09 06:23 PM
I'd say YES but, almost everybody has shelf pistons for SBC @ 1.00"
Posted By: hemiiroc
Re: Minimum Compression Heigth?? - 01/08/09 06:23 PM
.975 is way short
Posted By: bdaz smblk
Re: Minimum Compression Heigth?? - 01/08/09 07:15 PM
I have a .975 comp. ht with my 4" stroke and a 9" deck block and I won't do it again when I build my next motor.
Posted By: Laurent
Re: Minimum Compression Heigth?? - 01/08/09 07:47 PM
Why ? What's the trouble ?
Posted By: Blucuda413
Re: Minimum Compression Heigth?? - 01/11/09 04:57 PM
BTT, It looks like the answer is somewhere between .975 and 1.20. Any more inputs with experience and recommendatoons?????
Posted By: Bob_Coomer
Re: Minimum Compression Heigth?? - 01/11/09 05:45 PM
Not small block but.
The last Custom Diamonds I purchased was at 1.32 which didn't need oil rail supports. The Current Wiseco's at 1.29 do need them. So somewere in between...
The last Custom Diamonds I purchased was at 1.32 which didn't need oil rail supports. The Current Wiseco's at 1.29 do need them. So somewere in between...
Posted By: Cab_Burge
Re: Minimum Compression Heigth?? - 01/11/09 06:26 PM
Quote:It depends
What is the minimum CH in a smallblock which would keep the rings out of the pinhole???
What size wristpin and type of rod has a lot to do where the pin hole can be put in the pistons, right 
Posted By: Blucuda413
Re: Minimum Compression Heigth?? - 01/11/09 07:06 PM
Cab, I didn't even think about the wrist pin size. My current combo with a 9.56 deck heigth, 3.91 stroke, 6.4 Alum rods and .927 pin provides me the 1.21 comp heigth. You're right a pin of less than .927 would provide some additional room.
I'm just looking for a safe number to plan for my next build. At this juncture it's easy to also vary the rod length. I was planning on a 6.5 rod which may not work.
I'm just looking for a safe number to plan for my next build. At this juncture it's easy to also vary the rod length. I was planning on a 6.5 rod which may not work.
Posted By: Dos Snails
Re: Minimum Compression Heigth?? - 01/12/09 11:41 PM
I've had two different sets of dished JE's at 1.12 .One set had support rails for the oil rings & the other did not..