There are obviously some issues going on with the motor on the second dyno sheet.
Look at the fuel flow on both sheets, and the bsfc.
The first cam made 30 more hp while using 17lbs/hr less fuel.
The bsfc numbers for the second cam from about 5200 up are atrocious.
It’s a big red flag to see those numbers tank like that.
Unfortunately, the way he’s got the columns arranged on the sheet, there is no air flow data to look at.
If there were, I think it would be obvious something in the valvetrain was unhappy.
You had three valvetrain failures before you even got 100 miles on the car.
My approach would have been to use a more conservative cam profile, in an effort to increase my chances of success, and not been worried about if I were leaving 10-20hp on the table.
The Hughes cam you have coming should certainly make more power than what I would have used........given your situation.
Fast rate cams, designed to take advantage of the full diameter of the lifter are inherently less forgiving in terms of lifter bore placement and sizing.
I’m also not very confident the extra duration will remedy the octane requirement....... but to be honest, I don’t know that can be properly solved with any cam.
An 11.6:1 408 with a decent single plane, rpm heads, and that Hughes cam should easily make solidly over 500hp.
My feeling on the first cam peaking early is, you probably didn’t have quite enough spring load.
If you look at the recommended spring on the cam card, it’s a spring that has about a 400lb/in rate...... which is a fair amount higher than the single spring that comes on the RPM heads.
The other possibility is the motor was tested with 1-5/8” headers...... which would tend to lower the point where the peak occurred.
Oh, and IMO both of those runs are sort of “glory runs”.
Barely over 100* water temp?
C’mon....... that’s not reality for a street car.
Real world temps could have the motor end up wanting totally different timing and jetting.
I realize that you had nothing to do with that....... it just makes me question what’s going through the dyno operators mind when I see stuff like that.
I actually did that very test on a 12:1 bracket race 416.
Going from 165* down to 115* was almost a 10hp gain.
Car looks nice btw.
In the test description on the 2nd test, it says something “Ford”?
What’s that about?
