What do I look for on an old cam to see whether it's still servicable? I measured duration and lift on a few lobes and its at least in the ballpark of what I'd like(I think)(230ish at .050 @ the lobe, .298 lift at the lobe) cam maker did not respond to an ID request, but before I get too involved I need to know if the cam is in good shape or not. The lifter bottoms look good, very little wear marks that I can see but I would replace all the lifters in any case. The lobes are mostly black with very narrow white shiny areas from lifter contact. If the cam checks out service-wise I'll check timing details more closely.
Also, when doing a 050 check, is that measured at the lobe or at the valve? I measured at both .050 and .033 at the lobe figuring if it should be checked at the valve the 033 would be the equivalent once you allowed for rocker ratio. Flawed thinking?
Guidance much appreciated, thanks.
Reusing old cam?
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Re: Reusing old cam?
I know not much about cams, but it's my understanding that if the lifters are all convex (just put the base of one lifter against the side of the other and hold it up to a light source), and the wear patterns on the lobes all appear similar, it's acceptable to reuse the cam and lifters. However, they need to remain in the same block that they came out of, and each lifter needs to ride on the same lobe that it came off of. Any mixing, and there is a very probable flat cam in your future. I've also heard that new lifters on an old cam are also an invitation for disaster.
Reground cams and lifters are relatively inexpensive.
Danny
Reground cams and lifters are relatively inexpensive.
Danny
Re: Reusing old cam?
Unfortunately this engine was a basket case and all the lifters were stuffed in a bag so can't use them. I know about wrong lifter/lobe pairings but I hadn't heard about new lifters/old cam being a problem. I take it then that even having the lifters refaced wouldn't help?
Re: Reusing old cam?
Those lifters can be resurfaced for just a few dollars. There are several cam grinders that can do that for you.
China...Great Food...Crappy Tools
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Re: Reusing old cam?
I've never had a problem using new lifters with a used cam, but haven't done it in the last several years. The new engine oils have been reformulated and have a LOT less zinc, which is what helps lube the cam lobes and lifters, especially during break-in. I would think you would be okay as long as you use a good cam assembly lube and a good zinc additive in the oil for break-in, probably something from one of the cam manufacturers.NE57 wrote: I know about wrong lifter/lobe pairings but I hadn't heard about new lifters/old cam being a problem. I take it then that even having the lifters refaced wouldn't help?
Owner of the Poor Man's Hemi Cuda
Re: Reusing old cam?
for the price of a new cam , go for a new one at least you know it will be new