JD 3005 exhaust mods/replacement

[ovrszd]

Have you thought about back pressure and burnt valves? I don't know enough about it to ask intelligent questions so I ask silly ones. I wonder what it will sound like. I had a '55 ford with a 292, a nice cam and straight pipes. It sounded good to me and loud to some but the cops liked it and let me slide by.

Using my limited education, I was taught to worry more about burnt valves if running no exhaust due to rapid cooling. I've not heard of that issue with minimal backpressure. That said, the Hot Rod guys will say you need a certain amount of backpressure to build maximum HP. I think the difference would be so negligible on a tractor of this size that it becomes a non-issue. Just my opinion.

 

[sixdogs]

Using my limited education, I was taught to worry more about burnt valves if running no exhaust due to rapid cooling. I've not heard of that issue with minimal backpressure. That said, the Hot Rod guys will say you need a certain amount of backpressure to build maximum HP. I think the difference would be so negligible on a tractor of this size that it becomes a non-issue. Just my opinion.

I asked the back pressure questions in a thread a while back and the consensus was "don't worry about it". Not sure if I'm100% on board with that but that's what most guys said.

 

[dieselcrawler]

Gas motors respond to back pressure issues more than diesel, from what I recall, due to the higher RPM range. Burnt valves can become an issue if a motor is run with no manifold (exhaust ports open to cold ambiant air) but not likely an issue in my case. The larger pipe Im using will flow more, but being 3x longer will likely cancel out most of the gain.

 

[dieselcrawler]

A few minutes brainstorming tonight after doing the evening feeding yielded a solution to a couple issues. And being that the temps today were warmer, it didnt bother me to fire up the lil bugger, and Im sure its going to be too loud without a muffler of some type.

I think I can build a muffler with a rather basic baffle, and fit it along the frame below the side panel. It will be the lowest point in the system, and be a good location for a drain plug. It will also allow for a junction in the system, between the flange/down pipe/muffler assembly and the upper section that follows the limb riser over the roof. I can make simple pinch clamp. Nice to now have a clear idea of the shape things need to take.

 

[buickanddeere]

Gas motors respond to back pressure issues more than diesel, from what I recall, due to the higher RPM range. Burnt valves can become an issue if a motor is run with no manifold (exhaust ports open to cold ambiant air) but not likely an issue in my case. The larger pipe Im using will flow more, but being 3x longer will likely cancel out most of the gain.

Mixing up symptoms and cause .
The lack of back pressure does not burn valves. The leaner, hotter mixture caused by improved airflow burns the valves. If back pressure is reduced on a spark ignition engine without an O2 sensor and an injection system that will compensate and keep the mixture at the ideal ratio. This no valve burning and more power.

 

[ovrszd]

A few minutes brainstorming tonight after doing the evening feeding yielded a solution to a couple issues. And being that the temps today were warmer, it didnt bother me to fire up the lil bugger, and Im sure its going to be too loud without a muffler of some type.

I think I can build a muffler with a rather basic baffle, and fit it along the frame below the side panel. It will be the lowest point in the system, and be a good location for a drain plug. It will also allow for a junction in the system, between the flange/down pipe/muffler assembly and the upper section that follows the limb riser over the roof. I can make simple pinch clamp. Nice to now have a clear idea of the shape things need to take.

Yep, I can see all of that working fine. Very anxious to see the muffler design.

 

[dieselcrawler]

Being stuck in the house all day with the kids due to the wife working a double shift, all I could do to make any progress was think... And draw.

Here is a possible option of the muffler design. I also have another idea in my head that would be a little less labor intensive, but I like this one better.



The inner tube would be given a bunch of cuts about 1/4 of the circumference on each side the whole lenth of where its inside the larger one. Baffle rings are as much for support as baffles.

 

[ovrszd]

I think this would be very effective. Mufflers have vibration issues to deal with. So attention to construction will be required. But you got that.

 

[sixdogs]

I knew of a guy that built his own muffler and it came out great. He got the concept and specs off a muffler website. Flowmaster, I think.

 

[dieselcrawler]

I got a few things done on the muffler idea...



This part goes inside, it will need to be welded into the outter tube before the exit pipe/clamp can be attached.



I hope these slots will be enough to break up the sound waves, I may dimple them in or out or both, alternating slots. Not sure yet.