600HPS

CHECK TO SEE WHAT A VACUUM GAUGE READS, ALSO CHECK IGNITION TIMING 18436572. TOM

R Addiction

Sounds like a cam lobe is gone!!

600HPs...this ain't no Saab Son!!!

Craig B

I'm gonna start wrenching tomorrow so I'll let you guys know.

Thanks again for all the help and stay tuned.....

600HPS

HEY R, I THINK YOUR CORRECT! IF HE CHECKS VACUUM, THEN THAT WILL TELL IF THERE IS A WIPED LOBE. TOM P.S. I HOPE ITS JUST A CROSSED WIRE!

later

my money is on a cracked plug or crossed wire. was running good untill changed plugs.

later

R Addiction

I'm stickin' with a wiped lobe....It ran fine for a short time....then it started popping thru carb....possibly tightened a rocker to tight. Have heard of this before.

But for your sake I hope it is just a bad wire, plug or crossed wire.

Craig B

I'm not familiar with a vacuum gauge, how do you do it?

How else do you check for a wiped cam lobe? I thought you checked the oil filter to see if there is metal in it from the lobe?

What happens if it is a lobe? Full rebuild?

You guys are scaring me now!

bobbarker

Get rid of that carter, go with holley at least you have a starting point .Make sure you have a good coil.

Mr Gadgets

Craig,
go with the basics first. If you did wipe a cam lobe the metal will end up on the piston skirts, so a tear down would be in order.
You hook the vaccum gauge to the intake manifold and watch it.. if it bounces around then valve problems..possibly a cam lobe.
Do a search on the net for vacumm gauge info. There is way to read them. But at idle it may bounce some, then when off idle it should increase and stay steady. But look at ignition first. If you have a plug wire crossed it will pop back thru the carb.

Take it one step at a time, remember basics, dont panic till you have to. Do a compression test or a leakdown test. Remove the valve covers and bump the motor over, check each rocker for a loose one. If an ex valve isnt opening.. it can blow back thru the intake.
Roll the motor over and see if all the rockers are moving the same amount. If you suspect one, use a dial indicator to measure the valve lift.

Good luck and be patient, this is a time to learn and most of us have been here and done it..

Dick

Bulldog

I sincerely hope it is a bad wire or something like that, but the scary thing is that it pops regardless of ignition timing. A backed off rocker adjustment or a bad exhaust lobe forces exhaust to exit during the following intake stroke, firing off the intake charge. Being a new cam I would definitely check it out carefully before running the engine again. The more it is run with 'Gltter oil', the more damage done to EVERYTHING.

I had a 454 with a new Erson cam that was in the engine when I bought it. When it had a couple of hours of run-in time, it burped under load. I noticed none of the lifters/pushrods were rotating- a sure sign of trouble on a flat tappet cam. I don't think the lobes where machined right. POS cam lost one lobe with 2 others in early failure mode. Isky never failed me before or since...