Strait exhaust pipe

Tue Mar 25, 2008 1:01 pm

Everyone at the tractor pulls runs their tractors without a muffler. Will it hurt anything? Do i have to re jet the carb? Will it effect the valves like a 2 stroke moror? Is it really moer power?

Tue Mar 25, 2008 1:21 pm

Look through your muffler and you'll see that it resembles a straight pipe. Any very small difference will be because of reduced turbulence. It's hard to imagine how it could be harmful to your engine. Maybe they just like the sound better?

No carburetor change is necessary nor desirable.

There's a separate group here on named LIP. That stands for Long Iron Pipe. Maybe you'd like to join? :lol:

Tue Mar 25, 2008 1:49 pm

Theoretically you will get more power, but that is in theory only. also, the length of that straight pipe can make a difference, as can the diameter. Only way a person would ever know for sure is to hook up to a dyno, and then run the tractor first with no pipe or muffler, then run it with the straight pipe, and finally, run it with the muffler. I think the horsepower will be less with NO pipe or muffler, but probably not a lot of difference between a straight pipe or a muffler. Who knows?

Tue Mar 25, 2008 8:50 pm

For some of the shows I put a 1 inch / 1 1/4 inch bell reducer on my cub and run a pieced of 1 1/4 inch pipe for an exhaust. So far as I can tell it does not give anymore power, just makes it sound different.

Wed Mar 26, 2008 9:30 pm

how high above the hood should the pipe be ?


Thu Mar 27, 2008 7:07 am

If you are going to install a muffler, then 2 or 3 inches above the hood will do. If you are just running a straight pipe you can run it to whatever height you feel comfortable with. It is my understanding that the original pipe length was 17" including the threads on one end.

Thu Mar 27, 2008 10:43 am

this is something that iv heard from alot of old timers out there to how long to make the stright pipe, what they would do is use a real long pipe say 28" or so i guess it despends on tractor, then they would work it hard, ie tillage. a back mark would develop on the pipe at that point it would be cut. i guess the thought here was thats were the length was most effective.


Fri Mar 28, 2008 6:50 am

There is a formula for exhaust lenght based on the volumn of one cylinder. The idea is the gas fills the pipe before the next valve opens. With a megaphone pipe the expanding gas pulls a bit more fuel air mix in. This is mostly for 2-strokes though.
You'll go deaf in short order.

Wed Apr 02, 2008 7:59 pm

I run a dyno service on the weekends and a longer pipe creates more back presure in the motor.

More back presure creates more torque on the dyno. There isn't a rule of thumb that i can give because every motor is differnt.

On my pulling tractor the pipe is 18 " above the hood and 3" in dia.
We want to get it out as fast as were shoving it in .

To much rpm also kills the hp out put of these motors. The cam shaft on a 52 Super M runs out of power around 1900 rpm the torque #s start falling off fast .

Cheap easy power is a good "hot" coil [ high voltage] but if your going to use a automotive coil make sure you use a ballest resister.

All tractor coils have them built in so you don't see them. It will work with out one but the coil will get very hot.

Anyway a straight pipe sound great , have fun.

Thu Apr 03, 2008 11:19 am

no pipe or muffler at all could result in warped exhaust valves when a hot engine is shut off. hot on one side cool on the other. that's why drag racers stick something in the pipe at the end of a run. at least that is what i have been told.

what? me race?

Re: Strait exhaust pipe

Fri Apr 18, 2008 8:58 pm

Like all the diesel guys say, smoke+noise=power. I guess the gassers could say noise=power.


Sat Apr 19, 2008 11:00 am

There's a separate group here on named LIP. That stands for Long Iron Pipe. Maybe you'd like to join? :lol:

Yep, the LIP (Long Iron Pipe) club. The only qualifier is that you have a straight pipe on your cub instead of a pipe w/muffler. The pipe on Homely is 17" + the length of a muffler. :D

Re: Strait exhaust pipe

Sat Apr 19, 2008 5:08 pm

Rusty won the Cub Tug last year with a straight pipe. He's underslung with the muffler removed. Does he qualify? :{_}:

Re: Strait exhaust pipe

Wed Jun 11, 2008 3:44 am

Just wondering? Does the LIP site also have a link to Belltone hearing aids?? LOL ... 3&t=30353#

Re: Strait exhaust pipe

Wed Jun 11, 2008 7:27 am

If you use a pipe of about the same length as the muffler, the increases in noise level is not too bad, and I assume would take a long time to affect your hearing. Doing the same with an H or M and running under a heavy load would be a little different story though.