Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - More TQ than HP???
View Single Post
  #30 (permalink)  
Old 10-29-2012, 06:23 PM
techinspector1's Avatar
techinspector1 techinspector1 is offline
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 12,955
Wiki Edits: 326

Thanks: 762
Thanked 1,013 Times in 849 Posts
Quote:
Originally Posted by cdminter59 View Post
Yeah, that's the part I don't understand. A 350 chevy block has a deck height of 9.025. Add 1/2 the crank diameter, the rod length, and piston compression height on your pistons. The total comes to 9.0". How can the pistons be .040 in the hole? The Trick Flow heads have a 72cc chamber, that will put your static compression at 10.571 and the DCR at 9.493. You will have to use 110 octane with a DCR of 9.493.
Rebuilder pistons are 1.540" compression height, not 1.560", so the stack could be 8.980", yielding a piston deck height of 0.045" in a block with a block deck height of 9.025. Actually, it could be done with 400 rods too. Crank radius of 1.740", rod length 5.565", 350 piston with stock 1.560" compression height would make a 8.865" stack. I'm not saying this is likely, I'm just sayin' it's possible. In this short rod scenario, the crown of the piston would be down in the bore 0.160" with a 9.025" block deck height.

I want to re-figure the SCR and DCR, as the numbers don't seem right.
Cylinder 738 cc's
Chamber 72.5 cc's (deduct 3.5 cc piston dome from 76 cc chamber, then figure the piston as a zero value).
Piston 0
Piston Deck Height @0.040" in the hole at TDC 8.5 cc's
Gasket 3.3 cc's
Total 822.3 cc's
less cylinder volume
Total 84.3 cc's
Divide 822.3 by 84.3 and find 9.75:1 SCR
The 274 HO6 stick closes the intake valve at 31 degrees after bottom dead center @0.050" tappet lift and will make 8.764:1 DCR on the KB calculator.

Now, we need to find out from the OP what kind of fuel he runs and we will know that this particular combo will run on "X" fuel at 8.764:1 DCR with a 0.055" squish.

Last edited by techinspector1; 10-29-2012 at 06:33 PM.
Reply With Quote