I know him. I talked to him about a year ago when he was up a "hidden" rock drive off of hwy 30. I was going to go H/C then but ran into some financial difficulties at the time plus I needed to get the rest of the drivetrain done before I add too much more power.
Like the car and hopefully I will run into you at Gateway sometime.

 

Find out whats going on in the 4000 rpm area the hp and tq both take a dip there. Get that smoothed out and the upper rpm drop figured out and you're gonna like the final results.

 

What would cause a dip like that at 4000 rpm? I'm pretty sure I'm at max WOT timing at that spot, and I guess that could be something to play around with. Thanks for the suggestions and comments. I'll post more numbers after I have some time to mess around with it. Maybe next time I'll have some nitrous numbers, too.

 

if the springs are good to .620 does that mean that they coil bind there or they don't know what the seat pressures are. the pressure is what keeps them from floating. coil bind is what costs retainers and valves to go bye bye

 

It starts dying at 6000rpm, due to either the advance in the cam or it's just running out of air... could be float, but it doesn't have the sharp drop off that you normally see with that.

The 4000rpm dip is just normal.... you have enough overlap in that cam and probably a short exhaust system off the headers so you will see that with those two things.

Bret

 

Seat pressure, prevents valve bounce, the pressure over the nose prevents float and lifter pump up because if it's not correct the bounce will be worse if you don't control it over the nose.

The mass of the parts plays as much into this as the pressure, lighter parts are easier to control.

Bret

 

My graph looked identical to your graph, but at around 5700rpm. I loosened up the valve lash and it pulled strong to 6600. That was with comp Rs.

With the stock lifters I just went to around 3/8s and haven't had it on a dyno to see what the curve is doing.

 

Thanks Bret. I'm going to have to get a hold of Joe to find out if any advance was ground into the cam or not. He never mentioned it if there was. What would cause the sharp drop at 6500? Even if it was supposed to peak that early, I wouldn't have thought that it would fall off that quick from 6500 to 7000.

 

Hey when mine actually floated the valves, it did look like a cliff dive. It was a 50 hp drop.

 

Exactly.

 

What happend to the air/fuel once the floating started?

 

Good question. My a/f stayed pretty constant as my power fell off.

 

The a/f didn't really change when they floated. It looks like it went just slightly richer.