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Camshaft Lobe Width?
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    Posted: Feb/11/2019 at 7:23pm
So just bought and returned a Comp Cam camshaft. It had lobes anywhere from 0.0406" to 0.460" wide.
I have 2x original AMC camshafts and they are both 0.500" to 0.508" lobe widths. In fact I remember all being at or near 0.500" lobe width.
Bought Comp before with 0.485" + lobe width.
Who sells AMC camshafts with factory spec lobe widths? I have not found it in a search, and the manufacturers don't seem to advertise it.
Duration, lift, separation ... are second priority to me as far as an engine build. 
Not a straight out performance builder, street power and longevity. Won't use aluminum roller rockers as their fatigue life cycle is 30,000 to 40,000 miles - 100,000 miles is the goal. 
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Points: 16 		Post Options Post Options   Thanks (0) Thanks(0)   Quote MattsGarage Quote  Post ReplyReply Direct Link To This Post Posted: Feb/11/2019 at 8:54pm
I have a howards hydraulic flat tappet here. Measures .503 to .509. I just put a howards solid flat tappet in the new engine, and it degreed in near perfect.
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Thanks, Howard's it is.
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Another thing to note on howards, their lifters are the correct diameter.
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This is really interesting. 

I wonder how wide Bullet lobes are.
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Points: 696 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Trader Quote  Post ReplyReply Direct Link To This Post Posted: Feb/12/2019 at 6:15pm
Yes it is. Took a 360 apart a few years ago with an aftermarket cam with 0.430" lobes. The lifters and cam were shot. Cam was working the edge (rounding) into some of the lifters. 0.055" and the cam would have been near the lifter edge and likely everything would have been good.
On the pressure side of things, after many miles the cam/lifter contact area of the old AMC cams was about 0.250" and the top of the lobe 95% to 100%.
I would assume the less surface area you have the higher the pressure, at least that is the math I learned.
I believe AMC knew what they were doing when they designed the lobe width.
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Points: 898 		Post Options Post Options   Thanks (1) Thanks(1)   Quote imacarfan2 Quote  Post ReplyReply Direct Link To This Post Posted: Feb/17/2019 at 5:23pm
I just measured two cams for their lobe with. I only did one or two lobes on each and will check them all later. The cams were both older cams; one an Edelbrock Performer and the other the small Summit cam (K8600). All the lobes I measured were a hair over .500, maybe 17/32nds which is about .531, but maybe not even that much. My measuring device is in sad shape, so readings should be taken with a grain of salt. They are definitely over .500, though.
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My Comp Cams custom hydraulic roller cam has 0.570" wide lobes, wider at the base circle.
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