Gary Lewis Posted February 16 Share Posted February 16 Spark knock at cruise and tip in because you have so much advance and no exhaust to richen the mixture under high vacuum. The Crane instructions are on our site at Documentation/Electrical/Ignition and then the Instructions tab and then the Crane Cams Instructions tab. Link to comment Share on other sites More sharing options...
viven44 Posted February 16 Author Share Posted February 16 Spark knock at cruise and tip in because you have so much advance and no exhaust to richen the mixture under high vacuum. I had a bronco with a Edelbrock intake and I swore it had spark knock while cruising and when I tried to accelerate while cruising. Never quite understood why. Now it all makes sense Link to comment Share on other sites More sharing options...
viven44 Posted February 16 Author Share Posted February 16 The Crane instructions are on our site at Documentation/Electrical/Ignition and then the Instructions tab and then the Crane Cams Instructions tab. Ok, will check it out ! Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 16 Share Posted February 16 I had a bronco with a Edelbrock intake and I swore it had spark knock while cruising and when I tried to accelerate while cruising. Never quite understood why. Now it all makes sense Inert gas, which exhaust gas is, slows the flame advance. So they increase the spark advance significantly when the vacuum is high, like at cruise. Given that, you have to dial the advance back or you'll have spark knock. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted February 16 Share Posted February 16 The Crane instructions are on our site at Documentation/Electrical/Ignition and then the Instructions tab and then the Crane Cams Instructions tab. Shows what I know about this place! 😂 Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 16 Share Posted February 16 Shows what I know about this place! 😂 I'm the archivist. You suggested we archive that document, so I did and even remembered where I put it. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted February 16 Share Posted February 16 I'm the archivist. You suggested we archive that document, so I did and even remembered where I put it. I guess I'm good for something, once in awhile.... Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 16 Share Posted February 16 I guess I'm good for something, once in awhile.... All the time. Link to comment Share on other sites More sharing options...
viven44 Posted February 16 Author Share Posted February 16 All the time. Well I caught hopefully a mild variant of “while I’m at it” and decided to peek underneath the intake and I found a valley pan, which Jim advised against for the Edelbrock at least. Looks like I’m glad I got into the intake. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted February 16 Share Posted February 16 Well I caught hopefully a mild variant of “while I’m at it” and decided to peek underneath the intake and I found a valley pan, which Jim advised against for the Edelbrock at least. Looks like I’m glad I got into the intake. With the crossover active you want to keep oil from coking on the bottom of the hot intake and eventually dropping chunks of carbon into the lifter valley. The pan pretty much solves that.... But aluminum intakes expand far too differently than iron, and a one piece intake gasket will cause leaks (vacuum or water) at each head. Some intake gaskets have restricted crossover, or you can get them blocked and drill a smaller hole in the sheet metal tabs. It depends if it's a race car, a lazy weekend cruiser that can warm up in the drive or if you're using it for a daily and just want to turn the key and go. Link to comment Share on other sites More sharing options...
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