Gas pipe setup

[Julio Almazan]

Hi:
Certainly, a real welcome find this group ... thanks for your data and links.

 

[Toni Lightbourne]

All are good choices. Here are some options that Alan offers. Natural finish, nickel or powdercoated, slip on or Hotpipe flex, internal stinger or external. The prices are resonalable as well. I tend to like the slip on clamped style which is less messy. [email protected]

 

[rhomodel]

Ideally you measure the lenght of the pipe from the center of the sparkplug to widest part of the pipe. But most commonly used measure is from exhaust port to widest part of pipe. As Roman remarked the BZM is indeed basicaly a 40 or 50 cc size cilinder, so the distance from center of spartkplug to exhaust flange is more then for example a QD or Zenoah. So I measured up the lenth of these:
BZM: 41 mm
QD: 36 mm
Zenoah: 32 mm
So correction for QD should be 4 mm shorter (that is about 1/6 inch)
for BZM it should be 9 mm or 1/3 inch shorter
Shorter here meaning that if the lenght for a zenoah from exhaust flange to widest part of part 13 inch is the optimal lenght, with a QD it should be 12 5/6 inch and with a bzm it should be 12 2/3...
However as with any set-up you need to find the sweet spot, so the given lenght is just a starting point as the characteristics (powercurve) of the engines are very different.

 

[AgafonovRoman]

Thank you. This is very helpful answer.

 

[David Bryant]

internal stinger or external.

what is meant, or difference, with internal or external stinger?

 

[Mark Anderson]

An internal sitnge runs up into the belly of the pipe an external sticks out the back. The internal is quieter.

 

[David Swisher]

I have ran as low as 12",longest 13.5,thats if I have no torque!