Kohler Aegis exhaust GLOWING cherry red

[AshleyMckendree]

Ok we have put our garage mount together with the 31hp aegis efi motor, I haven't had a "slide in" for some time, mostly direct drives...

Starting at around 1500rpm under no load, the exhaust manifold I welded up glows CHERRY RED... I've wrapped it in that "titanium exhaust wrap", and you can see the red through it', i even made it 2" all the way to make sure there was minimal back pressure
. Is this normal? Here are some pics:
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[Able 1]

Personally I would get rid of the wrap.. My 25 horse Kohler will glow also, though it has to be a lot darker to see it. I always thought a larger pipe would help.. Maybe if those two pipes coming off the head were shorter it might help?? It might also help a little if you elbowed out of the first head to get it flowing out right.

 

[rwcarpet]

My 23 HP Powermatic would glow brite red, but could only be seen if the van was dark. But.....put your hand near it accidently, and you'll know it friggin' HOT! Even the Genesis Ford carberated engine would glow at night when run full out.

 

[Larry Cobb]

Ashley;

Unless you have used stainless tubing . . .

I would NOT wrap the exhaust pipe.

It will cause the steel tubing to corrode much faster,

due to the higher temperatures.

Larry

 

[FredC]

poor manifold design.......wrap contributing

may also have weak ignition allowing more unburnt into the manifold

 

[AshleyMckendree]

Ashley;

Unless you have used stainless tubing . . .

I would NOT wrap the exhaust pipe.

It will cause the steel tubing to corrode much faster,

due to the higher temperatures.

Larry

Thanks for the reply Larry, I sprayed the manifold inside and out with VHT ceramic coating and had it baked, will this prevent the corrosion?

Also, this motor has a total of 24 minutes run time, brand new :/

I designed the manifold to be free flowing with 2" all the way, other manifolds I've seen on TM's use 1" all the way, with bigger motors than mine.... Maybe the velocity of the larger diameter exhaust is too slow?



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[Shane T]

It's normal. The carbon steel won't last. Doesn't matter if it's wrapped or not, coated or not. Been there done that. The only thing that can be carbon steel is the head flanges. You may also have trouble with it cracking between the tubes because of expansion. If you're not using the exhaust for heat I'd get an exhaust manifold/muffler from Kholer. This one was made with SS pipe and carbon steel flanges and sensor nut. It was also mig welder with the wrong wire. It eventually burned up the welds, nut and flanges.

 

[Ron Werner]

perhaps unwrap it but put a couple layers of heat sheilding around it so no one gets fried off that! Damn that's hot!
I've seen mine get red but nothing like that, just a nice glow you could see when dark. Haven't looked to see how the new engine is heating up the exhaust.

 

[clean image]

do you have your oxygen sensor hooked up?

call johns and have them make uou a nice SS with curved bends

I have same engine, only can see when darker

dull red is about 1200 i believe

sounds like missing o2 sensor allowing 2 much fuel

 

[AshleyMckendree]

O2 sensor his hooked up and in the exhaust flow


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[Shane T]

I have run with and without the sensor. Makes no significant difference in the exhaust temps. I have even check back pressure and there is none. It has run this way since day one, approx. 2500 hours.

 

[Nate The Great]

Ashley;

Unless you have used stainless tubing . . .

I would NOT wrap the exhaust pipe.

It will cause the steel tubing to corrode much faster,

due to the higher temperatures.

Larry

Yea, don't wrap carbon steel... I learned the hard way.. lol, plus I was told that the engine needs a specific back pressure to operate correctly over the long haul..