Would like to do dual exhaust conversion

[Marks481]

holy old thread revival, batman.

That out of the way...

I finally had all the pieces and parts that I needed to do my muffler mod. I cut a couple of flanges out of 3/16" 304 stainless, based on using 3/4" schedule 10 tubing for the manifold. I intended to enlarge this to 1" (with a 3/4->1" reducer) after the elbow welded to the flange.

I pulled off the PT muffler, and was surprised to find the exhaust ports on the engine were 1.09" ID (which is the same as the ID of the 1" schedule 10 tubing). It seems wrong to put an exhaust manifold on this of a smaller ID (like PT did, no big surprise).

I guess I will bore out my flanges and use the 1" schedule 10 elbows instead. This will be tough based on the amount of room on teh flange, but I think that I can orient the flanges vertically; the robin engine has places to put studs (although they aren't tapped) for vertical flange placement.

 

[SnowRidge]

I pulled off the PT muffler, and was surprised to find the exhaust ports on the engine were 1.09" ID (which is the same as the ID of the 1" schedule 10 tubing). It seems wrong to put an exhaust manifold on this of a smaller ID (like PT did, no big surprise).

I think I mentioned PT's using a "step down" exhaust manifold on their welded up muffler when I pulled mine and replaced it with a stock Kohler muffler. I'm certain it is one of the contributors to the PT running hot syndrome.

 

[Marks481]

I kind of remember the soot rings on a picture of your muffler header (that look like mine does, since the PT built tubes are a smaller diameter and are not located concentric with the exhaust ports) and your post-mortum of the PT muffler. ahh, here is the post:

http://www.tractorbynet.com/forums/power-trac/37706-exhausting-pt-425-a.html#post421849

The hole that they cut in the square cross-member header doesn't line up with the stub tube (there is about a 1/4" lip), giving a further blockage. Definitely not the ported and polished job that most tractor racers would expect....

 

[SnowRidge]

Definitely not the ported and polished job that most tractor racers would expect....

LOL. Exactly.

 

[MossRoad]

Definitely not the ported and polished job that most tractor racers would expect....

Now you went and made me spit my beverage all over my monitor!

 

[KMA]

Boy, if anyone can come up with plans, a kit, or custom built dual exhausts for the Robin powered PT 4XX I would be pretty excited. Anything to make my tractor run a bit cooler would be welcomed. I just don't have the tools, skills or time right now to do something like this myself. Also, if someone could just weld up some flange adapter thingies to mate to the engine and are threaded on the other side for piping, that would be pretty neat too.

 

[SnowRidge]

Boy, if anyone can come up with plans, a kit, or custom built dual exhausts for the Robin powered PT 4XX I would be pretty excited. Anything to make my tractor run a bit cooler would be welcomed. I just don't have the tools, skills or time right now to do something like this myself. Also, if someone could just weld up some flange adapter thingies to mate to the engine and are threaded on the other side for piping, that would be pretty neat too.

Check with Robin. Kohler makes flanges and such for their line. Robin may also have something similar

 

[Marks481]

Boy, if anyone can come up with plans, a kit...

Look at post #6 on the previous page. Rivco doesn't have his PT180 anymore, but he might still be interested...

http://www.tractorbynet.com/forums/power-trac/108050-would-like-do-dual-exhaust.html#post1229413