[70 bird]

Wide band A/F meter?

[p4msi1]

Charlie, I pulled the motor down and the rod bearings showed too much timing. The valve relief scallops on the edges of the pistons, where it gets paper thin, was cracked and broken. I ground out the thin areas and polished to a smooth finish. I had 10 degrees pulled but will go to 16 and work it from there.


70 bird, I have a chassis dyno with a wide band showing 12.7/ 12.6 A/F. I will richen it up a bit. Strange thing is that on a 300 pill it only picks up 141 HP. Motor puts down 612 and on spray it put down 753. It is blowing through the converter though. I called PTC and they sent me a nitrous converter. So I am making changes.

Steve

[charlie66]

Originally Posted by p4msi1

Charlie, I pulled the motor down and the rod bearings showed too much timing. The valve relief scallops on the edges of the pistons, where it gets paper thin, was cracked and broken. I ground out the thin areas and polished to a smooth finish. I had 10 degrees pulled but will go to 16 and work it from there.


70 bird, I have a chassis dyno with a wide band showing 12.7/ 12.6 A/F. I will richen it up a bit. Strange thing is that on a 300 pill it only picks up 141 HP. Motor puts down 612 and on spray it put down 753. It is blowing through the converter though. I called PTC and they sent me a nitrous converter. So I am making changes.

Steve

Did you figure out the percentage of slip of the converter ?

What was the mph verse rpm with your spray dyno run?

What psi do you free flow your NOS regulator to?

Do you know what degree of timing the Tiger heads peak hp at N/A ?

[p4msi1]

Charlie,

Can't remember the slip % but 22 mph loss.

5 lbs. fuel flow

at peak power total timing is set at 34.8, initial is about 14.

Piston lands look good, tops of pistons had detonation marks. All the rings spin free, no friction. I went back on my dyno sheet and the A/F ratio was 12.3 and not 12.7 as I said earlier.

I thought I had a 12* module in the retard box but it was a 10*. I will put a 16* module next time and work from there.
Basically The shift light stayed mostly on the entire 1/8 mile run. (set at 6800) I just kept shifting it. It used to come on right before I cross the stripe on a 1/4 mi run.

[p4msi1]

Charlie, I ran a timed 1/8 mi run and it went 6.01 at 118. 60' was the same as on motor 1.38. It was turning over 6800 rpms at 118 mph. Probably close to 7000 rpms maybe a little more. On the motor it would be trapping 133-135 mph.

Steve