4cyl.4000 exhaust sizing

[Douglas Miner]

I'm replacing the exhaust pipe on my tractor and I
have a bunch of pipe. The pipe I took off goes
from 1.5" after the muffler to 2.25" under the
tractor. Is there a reason for this or could I
run. The 1.5" the whole way? I have both size
pipes on hand.

 

[Keith Williams]

Douglas,
The 4 cyl 4000 had a slight increase in hp. Know why? One of the reasons was they increased the size of the exhaust system!! All the way thru from the elbow to the tail pipe.
Use what ever size you want, but for max HP you want to have the exhaust size as large as you can get. Thats the whole way through! So if your muffler is smaller, then that will be the constriction point.
I know when you walk in to a parts store, you will get a "will fit" part. For the 4000 you need the bigger sizes. I think they were 2" stuff or bigger. IIRC
I know my 4000 sounded like it had more power when I took the mish mash of parts off of it and went to the larger size exhaust parts. Might have just been my imagination!
HTH
Keith

 

[rustyfarmall]

I'm not even a Ford guy but I think 1 1/2" exhaust is just too small. 2" or bigger would be my suggestion.

 

[Dean]

Ford 8/9xx tractors use a muffler with 1 5/8" inlet and outlet.

The 8/9x1 and 4 cylinder 4000 tractors used a muffler with a 2" inlet and a 1 7/8" outlet.

Both exhaust systems are entirely adequate for these engines operating at 2100 RPM rated speed.

Though the 8/9x1 tractors are rated about 5 HP higher, these tractors also have larger carburetors and air cleaners and use noticably more fuel. The HP increase is mostly the result of a compression increase.

Dean

 

[Texasmark1]

An internal combustion engine is essentially an air pump. Suck it in, work it, and blow it out. Anything that reduces the losses in this system is a boost in output.

Back when we were teens we would take a single exhaust car to a muffler shop and have duals put on. Anybody reading this knows what I am about to say next. It worked, besides having Smitty Brand glass packs to get all that noise we thought we had at the time to "make our statement". Ha!

So now here I am a senor and all the "jocks" running around in their P/U's with their noisy mufflers.....seems so silly. Grin.

In retrospect, when I was having a set of duals put on a '71 Chev station wagon (big mistake.....SW's are huge resonators), the owner of the muffler shop was standing next to me. I asked him something like.....what do you use on your car or something to the effect? His answer was he makes it as quiet as possible. So there it is from the "hosses" mouth.

Mark

 

[rustyfarmall]

(quoted from post at 07:05:18 03/29/13) An internal combustion engine is essentially an air pump. Suck it in, work it, and blow it out. Anything that reduces the losses in this system is a boost in output.

Back when we were teens we would take a single exhaust car to a muffler shop and have duals put on. Anybody reading this knows what I am about to say next. It worked, besides having Smitty Brand glass packs to get all that noise we thought we had at the time to "make our statement". Ha!

So now here I am a senor and all the "jocks" running around in their P/U's with their noisy mufflers.....seems so silly. Grin.

In retrospect, when I was having a set of duals put on a '71 Chev station wagon (big mistake.....SW's are huge resonators), the owner of the muffler shop was standing next to me. I asked him something like.....what do you use on your car or something to the effect? His answer was he makes it as quiet as possible. So there it is from the "hosses" mouth.

Mark

Never could find those Smitty's around here, but we sure went through a lot of the Walker "blue swinger" glass packs, and a few guys used the "cherry bomb" mufflers. I even experimented with those Thrush mufflers on a '64 LeMans but they just sort of disintegrated after about 2 months, so I did away with mufflers altogether and ran dual straight pipes. Those pipes exited right at the rear bumper, so it was actually very quiet inside the car.

 

[showcrop]

You must be too young to remember Bill Cosby and "PIIIIIPES!!! PIIIIIIIIIPES!!!!!

 

[Douglas Miner]

I think one of the previous owners did a little customization. The pipe exiting the exhaust is 1.5" OD and it is in good shape down till the underbelly of the tractor. I will most likely slide a piece of 1.5" ID pipe over it and bend it to line up with the pipe under the tractor. My tractor fund is used up for now.

 

[Texasmark1]

I remember hearing of the cherry bomb. Some guys also had a
cutout switch where they could divert the exhaust around the
muffler when the wanted to show off and the cops weren't around.

Had a friend in a small town that had one cop. Town was thinly
stretched along the highway. They'd figure which end of town the
cop was in and go play in the other. Great sport.

Mark

 

[504-1]

I have one in the shop now, 1.5 all the way. If I had a bender I would run 2".

 

[cdmn]

I read about one company that got complaints from farmers about gear noises. They decided to put a louder muffler on the exhaust. No more complaints about gear noise, and the farmers thought they had a more powerful engine.