318 cam

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RustyRatRod said:
They will still grind the DEH cams, but you have to call and request it. You won't find them listed anywhere anymore. Kinda dumb because they were a good line.
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In his new book; High Performance Cams and Valvetrains, Billy Godbold states Comp Cams has a room with something like 20,000 masters stashed away. Crane and Isky are probably the same. Many of those old profiles worked well for many people. The thing is that R&D has shown some new ideas or revelations that promote valvetrain stability. A lobe profile could unsettle the valve spring causing it to surge. Valve float or spring failure can result.
DV tells of a cam PAW sold that was something like a 4th or 5th "once removed" copy of another manufacturer's cam that had a "deviation" in it that caused spring surge.
 
273 said:
Not to sure but the swap from stock intake & Q jet to airgap & demon straighten it out, probably able to tune the demon better.
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QJ and TQ are similar in design, along with the AFB Carter and now Edelbrock carbs. Tuning just requires getting your head wrapped around it.
Seems racers all understand Holley style carbs and tuning using jets and air bleeds. Same thing, just a different way of going about it.
Then there are the Constant Vaccum or Constant Depression carbs used by the Limeys; SU and Stromberg. Plug those into your Funk and Wagnal's and figure out tuning them.
 
Dale Davies said:
In his new book; High Performance Cams and Valvetrains, Billy Godbold states Comp Cams has a room with something like 20,000 masters stashed away. Crane and Isky are probably the same. Many of those old profiles worked well for many people. The thing is that R&D has shown some new ideas or revelations that promote valvetrain stability. A lobe profile could unsettle the valve spring causing it to surge. Valve float or spring failure can result.
DV tells of a cam PAW sold that was something like a 4th or 5th "once removed" copy of another manufacturer's cam that had a "deviation" in it that caused spring surge.
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:rolleyes::realcrazy:
 
Dale Davies said:
Just confirming, if they still have the masters and you call and request a cam they can do it. A modern catalogue has a lot of current profiles and grinds, so keeping older cams listed would be too much for the sales they might attract.
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I was thinking more about the "valve spring surge" stuff. Some of these guys just make crap up I think.
 
RustyRatRod said:
I was thinking more about the "valve spring surge" stuff. Some of these guys just make crap up I think.
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Well, Billy mentions it in his book. Might be good to get a copy.
Then there are the high speed videos on a Spintron showing valve spring surge.
Judge for yourself.
 
Dale Davies said:
Well, Billy mentions it in his book. Might be good to get a copy.
Then there are the high speed videos on a Spintron showing valve spring surge.
Judge for yourself.
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I've seen those. IMO that doesn't come from the camshaft, but valve float and possible bad or inadequate springs. There have been as many cam grinds as blades of grass through the years. If the camshaft was the source of that problem, I think we'd know it beyond a shadow of a doubt. It'd be a lot more than a theory. I believe these guys sit around and think too dang much.
 
RustyRatRod said:
I've seen those. IMO that doesn't come from the camshaft, but valve float and possible bad or inadequate springs. There have been as many cam grinds as blades of grass through the years. If the camshaft was the source of that problem, I think we'd know it beyond a shadow of a doubt. It'd be a lot more than a theory. I believe these guys sit around and think too dang much.
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I think we can agree that spring surge source is loss of valve control and harmonics or natural frequency in the valvetrain. Could be flex in the pushrod or rocker arm.
 
Dale Davies said:
I think we can agree that spring surge source is loss of valve control and harmonics or natural frequency in the valvetrain. Could be flex in the pushrod or rocker arm.
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Beehives take care of some of that?
 
toolmanmike said:
Beehives take care of some of that?
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Yes, and conical. Each coil has a different natural frequency so the coils do not excite eachother.
For my 1966 Ford 289 heads the installed height is 1.65". Beehives all seen to be 1.8". Just a couple of years with the short installed height. The HiPo 289 had 1.78" installed and newer SBF heads are that also, so the Beehives could be used on them. Would have liked to use them.
 
Dale Davies said:
I think we can agree that spring surge source is loss of valve control and harmonics or natural frequency in the valvetrain. Could be flex in the pushrod or rocker arm.
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I'm not debating it happens. Just the cause.
 
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