|
Re: 440 Dynamic Compression and Pump Gas
[Re: 7e5dartsport]
#1179441
02/19/12 03:39 AM
02/19/12 03:39 AM
|
Joined: Mar 2010
Posts: 1,880 Out in Left Field, NY
bobs66440
OP
top fuel
|
OP
top fuel
Joined: Mar 2010
Posts: 1,880
Out in Left Field, NY
|
Quote:
from the cam card, i see you calculated dynamic compression ratio (dcr) from .050 duration numbers . you cannot do that. you need to use advertised numbers. from the advertised duration and max lift degrees (both on the intake) , i calculate the intake closing point is 70* abdc ( 109 + 282/2 - 180) . using this (70*) and the other engine specs you stated, gives me the following results : static cr is 9.35:1, dcr is 7.13:1 , and cranking pressure is 137 psi, which, in my book , will be fine with 91 octane. in my opinion, you will need as much as 37-38* timing
Thanks for the info. I'm still learning.
I was just curious, how you came up with the 7.13:1 dcr. Originally, I input 110 ICL by mistake, that's how I got the 71*. Using the calculator I have with this 70* info, I come up with 7.054:1?
Not that it really matters that much, just struggling to understand.
|
|
|
|
|
|