ok was breaking in cam have alittle over 15min on it and the tach jumps to like 8,000 but the motor shuts down Tried to start it and it ran for like 2 secs and did the same thing. It is a hei on 454. Is 15 min ok or do I need to go longer? Any ideas why it would just shut down?

Gas?

it's got gas.

Electrical maybe? your engine certainly didn't jump to 8000:D .

No it just shut down.

Is 15 min ok or am I looking at another flat cam?

I suppose you could do the first oil change. :D

Getting through initial start-up is most critical. As long as you keep the rpm up once you find the problem, you should be ok. I would try to keep the cranking time to a minimum, just to be safe.:thumbsup:

some kind of problem with the HEI, probably on the primary side like the pick-up coil or module.

there's no reason to assume the cam is toast because of this. what you want to avoid is slow idling. If it dies that's not slow idling.

i agree with tom, if the tach jumped but the motor didnt rev...plus that pesky dieing thing, gotta be the ignition, and as long as the lifters aren't sitting still without rotating on a turning cam, why would it be shot? if every cam was ruined by the motor stopping during initial run-in, well, ....i know id have at least a couple hanging on the wall.

This may make you feel better or laugh. I recently was going for a 25-30 new cam break-in run AND after 17 minutes #5 plug boot caught on fire and I mean on fire so I had no choice but to shut her down. Cam seems fine, have driven several hundreds miles and it runs fine, well except idle quality problems but that is not related to a bad cam lobe for sure.
I let her cool down along with me because I was mad at myself for not having a buddy to help out with the run. (timimg was retarted and that is why the boot got so hot it caught on fire). Changed the oil/eos and filter and all seems well. I hope you will be ok also.

Jesse

"retarted" :)

Well guys, I let the motor cool and it started right up so I let it run for another 10 mins or so for a total of about 25mins. Then I turned the idle and set the timing. Then shut it down and changed the oil. So am I good to go? Is there any thing I should avoid. Like intown driving or anything or is thing good to do anything?