440 Dynamic Compression and Pump Gas

[bobs66440]

 I used an online calculator and came up with 8.53:1 DCR.


Stealth aluminum heads

Static CR 9.35:1

bore 4.35
stroke 3.75

Here's the actual info after degreeing the cam:

Int open - 1* BTDC
Int close - 41* ABDC

Exh open - 54* BBDC
Exh close - 2* BTDC

Lobe centerline - Int 109* ATDC
Lobe centerline - Exh 120* BTDC

How will this be on pump gas? I read that 8.1:1 DCR or so is good. Is mine too high? What's optimum?

Thanks  

[Chryco Psycho]

with Alum heads you disapate more heat so ideally I try to target 10.6 :1 with alum heads
Using alum heads & only 9.3 compression it should run on reg fuel without detonation

[mhinders]

If you notice the dynamic compression is bit on the high side for your purposes you can retard the cam a few degrees and thus lower your dynamic compression. If you have a "bad" induction system your real dynamic compression will be lower...I'd start with what you have...