Visit The Dirt Forum for More Information

Author Topic:   Cam lobes worn out
340duster
Member
posted July 24, 2002 01:42 PM
I am posting this for a friend. Having problems with wearing out lobes on cams in a smallblock chev. Have ruined 2 cams in 5 race days. First was a comp cams hydraulic one lobe went and dished lifter, second was a used cam with new lifters same problem different lobe. These are both hydraulic cams. The engine sees 6000 rpm max. Break in was 1500 rpm for 25 minutes. Any ideas on things to check. We don't want this to happen again.


KPLugnut
Member
posted July 24, 2002 02:05 PM
My best advice would be to call up Charles at Camcraft (see link, he's a sponsor of these forums).
He will explain the best most fail-safe procedures for proper cam break-in.
Just running the motor at a low rpm for x-minutes is not the answer.

Charles loves to talk racing, too. Great guy, and VERY much at the cutting edge of cam tech, too.

Hope that helps...

KPLugnut

dirtbuster
Member
posted July 24, 2002 02:05 PM
What are the specs for this cam.. duration and lift etc..

What are you using for springs?

What did you use for oil and camlube?

How did you set the valves initially??

What are you using for rocker arms?


[This message has been edited by dirtbuster (edited July 24, 2002).]

[This message has been edited by dirtbuster (edited July 24, 2002).]

AIRFLOWDESIGN
Member
posted July 29, 2002 12:43 AM
I'm just wondering if the cam is all the way in the block and both timing gears are flat surface with each other. Also how far are the plungers going down in the lifters after rocker arm ajustment and how are the rocker arms being set? Ron www.airflowdesign.com


340duster
Member
posted July 29, 2002 01:22 PM
Well so much for trying to help a friend, he was reluctant to give any cam specs (he is my main competition - I don't know why he cares anyway because I race a dodge). But anyhow I think we have found the problem. He has double valve springs installed in his heads and left both springs during the cam breakin period. So with the new cam we will increase break in rpm to above 2000 and remove center spring. I am sure this will solve the problem. Thanks to all for your input.


340duster
Member
posted July 29, 2002 01:24 PM
The rocker are set while the engine is running 3/4" turn from "clicking noise".


Monster
Member
posted July 29, 2002 05:01 PM
LOL! He doesn't know how to break a cam in, but has been building engines long enough to have a "secret" one! I think he's got it backwards! Have some fun. Next time you help him, pick up a lot of his parts, look at them REAL close for an extended amount of time while mumbling unintelligibly and running your fingers over them, and when he asks you what you're doing , just say "Nothing.", and pick up another. I guarantee this will drive him nuts.


scrapiron
Member
posted August 11, 2002 07:46 PM
cam break was the issue, he ran good this weekend no cam problems.


Back to the Archives