460 Truck Engine
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Junior User
Joined: Nov 2010
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From: Montana
460 Truck Engine
I've got an 86 f250 with a fresh 460 I rebuilt. Bored .040 over, rebuilt heads, rv cam (can't come up with duration off my head .5 something) with edelbrock performer intake and 750 carb. The timing set I bought had three keyways in the cam gear. I read into it and decided to use the advanced timing keyway. Truck runs great, did a proper break in before I tried to open her up. First thing I noticed is the engine hesitates and loses power under heavy acceleration in the 3000/3500rpm range. Is that because of the advanced cam timing or the high lift of the cam itself?
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Joined: Jan 2014
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Could be carburetor tuning, could also be cam timing. Generally when you advance can timing it brings the power band down lower. A .500 lift cam should pull hard into the 4000s. When installing a cam you should always degree it in according to the specs.
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Junior User
Joined: Nov 2010
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From: Montana
Totally agree with the cam timing, think that may very well be my issue, need to get to my cam papers and adjust it the way they recommended.
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Joined: Jan 2014
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Perfect. Now do you have a degree wheel? You're gonna kick yourself, but you need to pull everything back off the front of the motor and degree it in. It's pretty easy to do, if you need help I would guess there are YouTube videos you can find to help. You'll need a piston stop and possibly some offset cam keys to get it perfect. I'm not sure on the years, but I've read that ford advanced cam timing for emissions, so if you advanced it even more that could explain your problem.
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