Narrow cam lobe separation
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From: Hoffman Estates Il
Car: '88 IROC T5 Vert ‘13 Vette
Engine: 305 TBI
Transmission: T5
Axle/Gears: 3:08
Narrow cam lobe separation
Any of you familiar with author/engineer David Vizard?
He is a big proponent of narrow lobe separation angles, even for the street.
Decide your amount of total overlap your engine needs, or can tolerate first , then the the lobe sep angle, then the amount of duration to not exceed the amount of overlap decided upon previously.
Has anyone actually used his recommendations? Less duration and narrower L/S angles to equal a reasonable amount of overlap for adequate vacuum, idle, etc.
Single pattern cams with 1.6 rockers are his recommendations also. (From his most recent book)
Thanks
He is a big proponent of narrow lobe separation angles, even for the street.
Decide your amount of total overlap your engine needs, or can tolerate first , then the the lobe sep angle, then the amount of duration to not exceed the amount of overlap decided upon previously.
Has anyone actually used his recommendations? Less duration and narrower L/S angles to equal a reasonable amount of overlap for adequate vacuum, idle, etc.
Single pattern cams with 1.6 rockers are his recommendations also. (From his most recent book)
Thanks
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From: 51°N 114°W, 3500'
Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
Re: Narrow cam lobe separation
Narrow LSA's are good for small displacement engines. It also makes a more choppy idle. 108-110 is common for a SBC. I wouldn't recommend 104 or 106 for a street engine.
My 540's cam has a 112 LSA and idles very smoothly at 1000 rpm. The bigger engines generally don't need the narrow LSA.
If in doubt about what your engine needs, call the cam manufacturer and ask them. With hundreds of different grinds available, I doubt you'll ever "guess or know" what will work best in your engine.
You want a custom grind or a grind recommendation, call Bullet Cams.
My 540's cam has a 112 LSA and idles very smoothly at 1000 rpm. The bigger engines generally don't need the narrow LSA.
If in doubt about what your engine needs, call the cam manufacturer and ask them. With hundreds of different grinds available, I doubt you'll ever "guess or know" what will work best in your engine.
You want a custom grind or a grind recommendation, call Bullet Cams.
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