The car should be peaking higher than what it is. The cam is similar to a gm847 and the heads are fully ported and pollished. Anyway, does it look like valve float? I didn't think it looked ignition related. The a/f seemed to stay the same even after it fell on it's face. I was trying to make these pulls to 7k.

 

what springs are you running?
i'm having similar probs without the drop off up top....i'm working on it will keep you posted

 

Looks like valve float to me.

 

Yikes, Looks like float to me as well.

 

Valve float, what springs are you running and what installed height.

 

That's the problem. I have no clue. I bought the heads, used, already assembled. I took them to a machine shop and they said the springs were good to .620" lift, but they didn't give me any other information. I figured I'd just put some Comp 918's on it, but I wanted to try and confirm that it is valve float before I do it.

 

Never just figure you just put, always check everything strong valvetrain are like the ligaments in your knee. I would not rev that high til you get better springs, 6k will be fine for now...

 

probably need more than 918s to spin that high

 

What would you guys recommend? The cam doesn't really come close to .600" lift.

 

I doubt that. There are plenty of LT1s running 918s around here that spin to 7k no no valve float. Although I've heard that Joe O cam profiles seem to like the comp 977s better than 918s...what cam are you running?

 

I'm running the Jolt-2, which is similar in size to the gm847, but with slightly less lift.

 

put some Comp 918's on it.

 

k-motion k-800's would be cheaper than the 918's. if you have the money go with the 918's, make sure they are set up for 140lbs on the seat.

 

I'm certainly no cam expert, but going off of what I've learned over the years (not to mention what I've learned on this site ) I'd recomend using either comp 977s or K-motion K800s with that cam. I'm sure 918s would work ok too.

 

Colin,

That's only that Joe was on here touting that beehives are junk.... in reality the Erson lobes he uses can work fine with the beehives, just set them up with enough seated pressure since they are pretty low lift anyways. (.570" lift or so)

Bret