Got a question for you guys.
This is in a Chevelle, but I figured there was no better place to ask than here...

My dad and I built a mild 383 for his Chevelle, vortec heads, all new parts, 400 crank, yadda yadda yadda. Here's the fun part, we used a Comp xtreme energy cam, and we're thinking that the cam was ground wrong. It'll run barely enough to keep running, and when it is running it spits some exhaust back through the carb(we're pretty sure it's exhaust, it smokes a bit out the carb and smells like exhaust) When you lash the valves to the thightness that they are supposed to be the car wont run at all, but when you set the valves(hydraulic lifters) like a solid lifter cam it runs like crap but it runs. As soon as you tighten one valve it sputters and dies. We are out of ideas, and was wondering if anyone on here might know.

Thanks,
Lynden

 

sounds like you installed the cam completely wrong with the timing chain. did you use a new crank gear and cam gear with your set? also try messing with the timing all over the place until you get it to run better if the cam is in the right spot. your balancer may have slipped and cause the timing issue. who knows, it could be tons of things.

 

Ya I wouldnt blame the cam....yet. That'd be rare to have it ground that wrong, and it would have to be pretyt wrong to get results like that.

 

I've been all through the motor. The cam is installed correctly and is timed correctly. The distributor is set correctly, as is the valvetrain. Unless four different iiming sets I have are all marked and cut wrong, then it isn't the cam install.

How could the balancer slipping cause a timing issue??

 

Loosen the dist and turn it both ways to see if it runs better. Ya can get it to sound good like that but be WAY to far advanced. Turn it toward the carb first.

 

well the balancer slipping could cause a timing issue because i'm sure you realize that the balancer has the timing mark on it, unless you time a motor through some other method ??? if it slips on the hub while the motor is running it can shift the timing a ton. i'd move the dizzy back and forth to get it to idle better and see where it ends up.

 

The cam was flat. We had too much oil pressure during break in and it caused the lifters not to bleed off, which in turn wiped the cam and about 14 lifters.

The timing was dead on.

 

time to tear it down and replace bearings now too then and i'm sure there's metal shavings everywhere. So you set the valve lash too tight and that wiped out a cam? I would imagine it would just hang valves open instead.

 

we lashed the valves right, just had too much oil pressure during break in. We were using a high pressure pump and didn't know it.

We're gonna clean out the motor and check a few bearings, but as long as none are scored or burnt, we're gonna replace the cam and oil pump and give her a go again.