View Single Post
  #8 (permalink)  
Old 05-05-2012, 06:46 AM
patrickt's Avatar
patrickt patrickt is offline
Half-Ass Member
Visit my Photo Gallery

 
Join Date: Jun 2005
Cobra Make, Engine: ERA #732, 428FE (447 CID), TKO600, Solid Flat Tappet Cam, Tons of Aluminum
Posts: 22,025
Not Ranked     
Default

Quote:
Originally Posted by krkucin View Post
10.1 Comp ratio, aluminum heads and a Comp Cam with 589 in. 615 ex. I do have a small airport 4 blocks away.
It's the duration of the intake valve that matters. The longer it stays open on the compression stroke the less "true compression" you really have. FWIW, I have a 10.6 comp ratio, aluminum heads, and 245 degrees duration at .050 on the intake valve and I run just fine on 93 octane gas with the ethanol mix (which is all I have in my area). The ethanol does clog up the air bleeds from time to time by flecking the zinc off the bowls, and that will make you think your engine has one foot and three toes in the grave.... Do a quick search on this forum to find the threads on that so you know what to look for.
Reply With Quote