Cam advance?
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Cam advance?
Hey guys, I'm mid-rebuild on my 89 Bronco 302/AOD, with stock heads, bored .030 with flat top pistons, long tube headers, and a Comp 35-255-5 cam. I'm curious, is there any benefit or harm to advancing my cam timing via my Cloyes 3 position timing set? I've seen a lot of threads talking about doing this and a lot of replies saying to leave it at zero (stock). What do you think?
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The cam card shows to have 4 degree's advance ground into it. Advancing would only move the cam 2 degree's anyway and since there is no mention of a checking intake lobe centerline with a degree wheel/ dial indicator - just stick it in straight up. That places the intake on aprox 110 centerline - exhaust 118 centerline with 114 lobe centers.
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New User
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The cam card shows to have 4 degree's advance ground into it. Advancing would only move the cam 2 degree's anyway and since there is no mention of a checking intake lobe centerline with a degree wheel/ dial indicator - just stick it in straight up. That places the intake on aprox 110 centerline - exhaust 118 centerline with 114 lobe centers.
Perfect, thank you.
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It really depends on what you are going to do with the vehicle. If you advance the cam a couple more degrees you will bring the power band down a couple hundred RPM, and power will drop off a couple hundred RPM lower on the high end. If you don't intend to rev the engine close to redline very often, there is some benefit in bringing the power band down to a more reasonable RPM, and getting the benefit of the aftermarket cam without having to rev the engine so high.
Laughing Gas
Joined: Apr 2014
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From: Shreveport, LA
Sometimes that is the case, other times it is not. What really matters are the timing events for what the engine needs at the RPM it sees. I had thought this way as well but had my custom cam grinder tell me this :
"Justin, You cant make blanket assumptions that advancing brings power on sooner or retarding later. In your case the exhaust positioning is driving things, so even with the earlier intake CL, the exhaust is better placed it will likely help top end; counter to the typical thinking."
Just throwing that out there for others, hoping it will help.
"Justin, You cant make blanket assumptions that advancing brings power on sooner or retarding later. In your case the exhaust positioning is driving things, so even with the earlier intake CL, the exhaust is better placed it will likely help top end; counter to the typical thinking."
Just throwing that out there for others, hoping it will help.
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I respect Justin's opinion, but my experience with installing performance cams in otherwise essentially stock engines with automatic transmissions and factory rear end ratios tells me BiggPoppa is going to be disappointed with the cam's performance without some extra cam advance, especially with stock Ford heads, which do not flow all that well. Let us know how it works out.
Laughing Gas
Joined: Apr 2014
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From: Shreveport, LA
Well, my statement wasn't meant to sound like I was disagreeing but more for a knowledge standpoint. I would also say in this case of the OP's motor advancing probably would help him considering the overall setup.
But the other statement that I included in the post was from my custom cam engineer whose knowledge I really respect.
But the other statement that I included in the post was from my custom cam engineer whose knowledge I really respect.
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