RE: Initial Pipe Length

I'm new!! How do you determine initial pipe lenght? I was looking to purchase a used pipe on the dock and the header was cut so the pipe was set at 12".... I was concered that due to the header being cut, it may not work in my application or allow enough adjustment.

I'm building a Aeromarine XXX w/ a CC Racing Pro Mod.

Thanks for the insight!!!

Here is how I determine the pipe length formy race mono hulls. I start off with the length from the exhaust port on the jug to the center of the band on the pipe set at 12.5" - 13". I then run the boat to find the best prop & run the engine in. After that I start moving the pipe in shorter in 10mm increments until it starts to pick up. I then move the pipe in in 5mm increments until I notice the boat slow down in the turns. At this stage I move the pipe back out in 4mm increments until the boat holds similar speed in the straghts and the corners. If it drops off in the corners you're not getting enough torque & need to lengthen the pipe.

This is all done with the carb settings set for optimum performance.

Hi,
Yeah, Dicko is pretty spot on as regards to the process of tuning in the pipe. My measurements are slightly different, but it is close enough, you should not have any trouble following his directions..

usttraw wrote: I'm new!! How do you determine initial pipe lenght? I was looking to purchase a used pipe on the dock and the header was cut so the pipe was set at 12".... I was concered that due to the header being cut, it may not work in my application or allow enough adjustment.

I'm building a Aeromarine XXX w/ a CC Racing Pro Mod.

Thanks for the insight!!!

Depends how they are measuring the 12"... I measure from the exhaust port face to the mid point of the pipe/band, following the centerline of pipe and header. 12" is a little on the short side, but in a mono with that ProMod it would most likely work well. Headers are cheap anyway..always good to keep a spare in case you cut one too short.

Guys, thanks for all your support!!! I ended up buying a new Powermaster from Carlo... couldn't help it and got a nice deal.. at least that's what I told my wife!

Forgot to ask.... is the measurement taken from the exhuast port on the cylinder face or from the outside face (facing hull) of the no-leak flange?

Thanks!!

AW

From the outside face of the port.

Got it. Thanks!!!!