Sport 40 pipe setting

[Ken Webb]

It seems someone told me 9 1/4 " from eng c/l to pipe weld. I don't remember what I was told. Info was in an old thread on here. Help. I'm setting up pipe now.

 

[Samuel Hagan JR]

10 3/4 is the sweet spot on a A/B parabolic.

 

[Ray Sametz]

10 3/4 is the sweet spot on a A/B parabolic.

Ditto on that Sam. Ken what pipe you using???

 

[Ken Webb]

'm using the AA pipe that came with the engine. I think it's parabolic. Not sure.

 

[Duck899]

10 3/4" is a conservative setting. Depends on prop, fuel used, boat, engine, altitude. I used to run a macs 10cc aero with muffler at 10 3/8" with a 1455/2 on 66% at 2200 feet elevation in a Mutt with an AA45.

 

[SayMikey]

Some guys can but I cant run less than 10 and get the boat come come hard off the corner.

 

[Duck899]

9 1/4" would be better suited to a rigger

 

[Samuel Hagan JR]

10 3/4 is very conservative. But we found that milling for clock time was easier and helped with Torque.

10 5/8 made very little change.

10 1/2 we lost torque and could not mill for the clock.

All of this with a MAC 45 on 50% Nitro. AB Parabolic which is the same as the A/A pipe. X647, and X450. It might have been a X648. Not sure on Altitude.

 

[Ken Webb]

Thanks guys.

 

[Robert Pickard]

I am running andy brown parabolic pipe on a cmb at 10 1/2