Topic: Different length pipes

[Stoli]

I've read some different opinions on the importance of keeping header pipes the same length. My application will be drag pipes with baffles. I could put the baffles at the same place in each pipe. It would seem obvious that if high performance was the priority then it would be important to keep them the same length but I have read that it wouldn't be significant for average street riding.

Anyone have any experience with this? Was dialing in the carbs a problem?

[LesterPiglet]

I wouldn't give it a second thought unless I was going racing or something.

[Dream750]

I would ensure that the pipes are equal length, but don’t let inside/outside measurements and the radius of the bends fool you. What you really want is equal volume on all four pipes. This is done by plugging the exhaust flange end with a cork or rubber plug and filling each pipe up with water. Empty the water into a graduated container and record the amount.
 
Repeat this step for the other three pipes. The pipe with the least amount water is your master. Cut the remaining three pipes (as necessary) to match the water volume from your master pipe. You will now have four equal volume exhaust pipes which will make carb tuning spot-on for each cylinder and makes for a better running engine. 
 
This method works well on Harley drag pipes too, but that's another story ...

[Stoli]

That's a really good idea for getting the pipes matched up perfectly. Thanks for the tip. So, I am curious, have you dealt with the issue before? Were the different pipes problematic for you?

[Dream750]

You’re welcome. Once time back in the 70’s I tried some “brand X” drag pipes on my 750. They were set up with the water volume trick and the old Snuff-or-Not adjustable baffles which had a very good (subjective) sound. I don’t recall them being problematic except to the cops.      

[LesterPiglet]

I wonder how the different length headers on a 4 into 1 affect carburation.
They don't.

[ekpent]

You’re welcome. Once time back in the 70’s I tried some “brand X” drag pipes on my 750. They were set up with the water volume trick and the old Snuff-or-Not adjustable baffles which had a very good (subjective) sound. I don’t recall them being problematic except to the cops.      

Try finding a cycle part for $1.95 nowadays.   

[KeithB]

Good p

I wonder how the different length headers on a 4 into 1 affect carburation.
They don't.

True. It actually affects cylinder scavenging and will, in turn affect the intake charge.