Cam Break in

[Kelly Burnside]

After having the cam checked on my 69 corvette 350/300 engine and verified that it is ok, I have installed the original cam and have replaced the lifters and push rods with new ones. What sort of break-in should I do for this combination? I know new cams/lifters need a break-in period but what is needed with old cam/new lifters combination? I presume that it will be the same procedure as with a new cam/lifter replacement.
Thanks

[Duke W.]

Re: Cam Break in

New cam, old lifters??? Why did you not reuse them? Maybe too late now
unless you marked them. Basic rule of thumb is new cam, new lifters.

Break in for OEM cam and lifters? Start it up and drive it.

Go buy a new set of lifters. Do not pass go. Do not collect $200.

Duke

[Doug C.]

Re: Cam Break in

Duke, He said OLD cam, NEW lifters

[Duke W.]

Re: Cam Break in

I don't think an old cam and new lifters is any better than new cam and old lifters. If you replace the cam, the lifters should be replaced. It may
work, but for the price of a set of lifters why risk it.

Duke

[Joe L.]

Re: Cam Break in

Duke-----

A new cam with old lifters is a "prescription" for a VERY short life for the combination. However, an old cam with new lifters might survive. I would be VERY reluctant to use the combination, but I wouldn't absolutely rule out its suvivability. For such a combination, though, I would say that the "2000 rpm for 20 minute break-in" would be much more critical than otherwise.

[Kelly Burnside]

Re: Cam Break in

Old cam, new lifters. When I took the lifters out of the car I did not mark them. (same with the pushrods!) I wanted to keep the original cam as I do not want to try to locate another cam that was similar. Probably only about a 100 dollars price tag but I still would rather keep the old cam.
Sounds like I will breaking the cam as if it were a new cam. Should be safer that way. Oh yeah, the cam was checked and was right on the money hense the re-use of it.
Has anyone ever done this before? I think that it has as I do see used cams all the time at swap meets.
Does anyone see any issues with this combination and what would be the worst case scenerio??

[Duke W.]

Re: Cam Break in

Exact duplicates of the OE cam are readily available from several sources.

I don't know what a "right on the money" cam means, but if there is no more than a few thousanths lobe height wear, it should be okay to reuse, especially if each lobe is mated to the original lifter.

Lobe height can easily be measured at the pushrod socket on the rocker arm, so there is normally no need to remove the cam or lifters to check for lobe wear.

Duke

[Clem Z.]

Re: Cam Break in

a new cam and used lifters as long as they are convex on the bottom will cause no problem. i have done it many times. new lifters on a old cam require you to polish the bottoms of the lifters on 400 wet and dry paper using oil as a lube. i have also done this with no problems.

[Kelly Burnside]

Re: Cam Break in

Looks like I should be ok. I did ask the guy restoring the car and he says it should be ok. I did not prep the bottoms of the lifters so hopefully that will not be an issue. The engine was totally rebuilt and the cam was within specs so the cam should be good. I used tons of assembly lube and I have primed the engine. So looks like it is good to go.
Thanks for the information.