Losing cam lobes

[AJ's]

I recently restored a '68 corvette stingray with a 427. We installed the Mutha Thumpr cam during complete engine overhaul. The cam did not make 40 miles. The supplier provided us with another cam and that one made it about 300 miles. We are using the lucas engine break in additive with the zinc. The engine was braought up to 2000 rpm upon start up for 15-20 minutes. What is causing these cam failures? The cam lifters and springs are all matched accordinly. I have a very upset customer and cannot afford to have any more cam issues. I have sent 2 private emails and have not had any response.

[amick]

What was the spring pressure during break in? What was your e-mail address and when did you send them? As far as why did the cam wipe a lobe that is hard to say and not something I have enough information on to guess at. I will say with a flat tappet camshaft even if everything is done correctly there is always a chance of failure. That is one of the reasons manufacturers no longer use them The only way to be guaranteeted of no lifter failure is to go roller. Fill free to email me direct at amick@compcams.com Did you purchase the camshafts directly from us? If not can you tell me where they were purchased and how long it has been since the purchase.

[AJ's]

The emails were sent using the link on your homepage. The cam was purchased thru Northern Auto Parts. Part#11-601-4, Not sure what# is the serial#, but the other # on the box is 2010061. The first cam was purchased 3/11/10 the 2nd cam 6/10/10. Springs are from Competition Products part#VSA7, Rated for up to .560 lift with 110lbs at seat and 345lbs at .560 lift. The engine builder that I used is not sure as to what is happening, and I have contacted multiple other builders and machine shops and no one has any ideas. This is the first issue we have ever had with a new cam, and to have it happen 2 times on the same project is weird.

[amick]

The springs sound fine for this setup. One thing I do see is that you are only bringing the engine up 2000RPM and letting it set there. The RPM should be varried during break-in and can be taking as high as 3000RPM. I don't think that is your actual problem but it is one thing that is not being done correctly. The other thing I would mention is that the BBC engine is the worlds worst about wiping camshafts due to the odd lifter bore angles. If there was actually a block issue then that could causing the problem. If it has been less than a year from the date of purchase then it is still covered under warranty and you could send it in for warranty consideration. If you simply want to avoid having to ever wipe a cam lobe again then it sounds like it is time to move to a roller camshaft.