Author Topic: Cam lobe went bad. do I rebuild or not?  (Read 2280 times)

Offline Chryco Psycho

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Re: Cam lobe went bad. do I rebuild or not?
« Reply #15 on: January 16, 2007 - 11:57:48 PM »
it is easy to check the brgs with the oil pan off already so that defiantly makes sense

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Offline 70B@rracuda

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Re: Cam lobe went bad. do I rebuild or not?
« Reply #16 on: January 17, 2007 - 04:07:14 AM »
I am a HotRod subscriber of many years and remembered an article that very much pertains to this subject. The article is about a year or so old and it mentions the woes of domestic flat tappet manufacturers about four years ago.
It seems that you may have cheaper off shore lifters because the US manufacturers cater to the OEM's, naturally, and the OEM's no longer use flat tappet engines. Read the article and you will understand better than I can explain it.

http://www.hotrod.com/techarticles/engine/flat_tappet_cam_tech/index.html

Bottom line, you need to go through your block. It is easier to do it now. Ensure that parts are not galled. Get good quality lifters!!! Get a lifter bore burnisher from Hughes, PN 8319, or Comp Cams lifter bore grooving tool, PN 5007. You want to ensure that your lifters are rotating properly or they can kill your new cam with a quickness.

I have an old(new in box) set of lifters my father gave me for a future 340 build, I may junk them because they are about four years old. They are Fed Mog, but they are the supplier not the mfg. No telling if they are Chinese or what. 16 new Comp Cams lifters are less than a 100 spot, thats worth the peace of mind.

Offline v8440

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Re: Cam lobe went bad. do I rebuild or not?
« Reply #17 on: January 17, 2007 - 07:03:22 AM »
One other thing to do:  USE OIL WITH ZINC IN IT, or use a zinc additive.  Zinc helps lobes and lifters break in, and it is something that has been removed from most oils in the last few years as a pollutant.  Some diesel engine oils still have zinc, but a few don't.  Make sure that some zinc is in your oil when you break the next cam in.  I've read about this causing problems several times now.

Offline Topcat

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Re: Cam lobe went bad. do I rebuild or not?
« Reply #18 on: January 17, 2007 - 07:36:45 AM »
Some more good advice. Thanks. Wow, that article sounds likw what may have happened.
Mike, Fremont, CA.


Offline moper

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Re: Cam lobe went bad. do I rebuild or not?
« Reply #19 on: January 17, 2007 - 08:47:55 AM »
wow..A real std bore '71 block? Definately take the time now...Wish I had one..lol.

Offline 67Vette427

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Re: Cam lobe went bad. do I rebuild or not?
« Reply #20 on: January 17, 2007 - 10:49:05 AM »
No doubt then if its an original 71 block! Make sure everything is cleaned up and checked by a quality shop or person. Hemi's are tough in their valve train with all the long push rods, rocker stands, rocker shafts, springs, spacers, shims and all the other goodies.

If somebody with an original 71 Hemi car ever needs a motor, you've got a little gold mine there.
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Offline Topcat

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Re: Cam lobe went bad. do I rebuild or not?
« Reply #21 on: January 17, 2007 - 01:02:22 PM »
 :iagree: After it's restored back, I haven't decided if I will keep it or sell it to help finance my car as it is. We'll see. I'll start teardown sometime from now till summer on it.
Mike, Fremont, CA.