View Single Post
Steve@Rennsport Steve@Rennsport is offline
Registered User
Join Date: Jul 2001
Location: Portland Oregon
Posts: 6,992
Originally Posted by Iciclehead View Post
Hey there Steve, glad to hear you are alive and kicking!
Hi Dennis!! Guilty as charged. :

What is max compression ratio you would go for with the SC cams or what combination would work?
It really depends on what local octanes you have. I would not go over 9.8:1 with twin-ignition, SC cams, and 92-93 octane fuel. Less CR for 91. Timing will need to be optimized for each configuration.

I am planning on 10.3 cr with DC35 cams on my 3.4 and hoping not to have the issue of the OP.
With twin-ignition and 92 or better, you should be OK.

Must admit I always thought that twin plug was a panacea for pinging on 911 engines....yoiks!
It does work very well, up to a point.

Local fuels and camshaft profiles both play a big role in selecting all the components and how things are set up.

Engine configurations must be considered and selected holistically, otherwise one can have the same problems that Trond has.
Steve Weiner
Rennsport Systems
Portland Oregon
(503) 244-0990
Old 08-21-2018, 05:43 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)