Coffman Sizzler with out manifold mount.

[WFO Speedracer]

Has anyone successfully run a Coffman sizzler pipe with a factory pipe exhaust manifold, the manifold I have has no provision for that chamber mounting point, I am sure I can fab one up but just wondering if it is really needed .

 

[Storbeck]

Seems like if you could put a chunk of foam and maybe a strap to support the chamber somewhere near the joint in the middle it would probably be fine, maybe?

 

[kevbo]

It will bounce off the engine mount. You will have to come up with a way to hold the chamber since it fits so closely to the engine and hull. I would try an EVA foam cradle glued to the hull just in front of the engine. A bead of silicone on the pipe and foam should keep chaffing to a minimum.

 

[WFO Speedracer]

I am going to slice the mount off the pipe and keep it. I am thinking I can come up with some kind of bracket coming off the two stock mounting holes for the stock exhaust bracket and then weld the mount back on where it lines up properly.

 

[kevbo]

A bracket that connects the chamber to the engine is ideal. I didnt mention that because very few can successfully make one.

 

[WFO Speedracer]

I had to give it a few love taps with the deadblow but I have it tucked in pretty well and I believe I can have the mount back welded on to line up with the upper manifold hole, a stud, coupler nut a long bolt and a spacer should fix her up nicely., I will know more when I get the engine back in the ski

 

[WFO Speedracer]

I have it all mocked up, It is just in mock -up stage though, I will need a better spacer then I have to wait till when my tig guy can weld the mount back on and tig up a couple of cracks in the pipe . The mock up engine is a nasty mess of a locked up 64x with a 650 cylinder but it works for this purpose.

I am contemplated using the 64x cases and carbs to build an 83mm Superjet engine with the option of going to a 760 cylinder later down the road , if I want to go that route.

 

[WFO Speedracer]

Looks like about a 5 inch Cantilever the vibrating Chamber is hanging off.

The one Cylinder Block Hole Threads might fatigue/fracture under that repetitive/reciprocating Chamber motion.

Maybe add/weld a Bracket onto the Exhaust Manifold to shorten that Lever Arm.

Then you could even just bridge that gap with a proper Lord Mount and not be attached to the Exhaust Manifold/Block Bolt at all.

You must be measuring in internet inches, my caliper says 2.125 total that includes the length of the coupling nut , at any rate a B pipe survives just fine without any mount there, these pipes are similar in so much as they have rubber couplers on both ends.

Basically all I am trying to do is keep the pipe aways from the side of the ski and away from the exhaust manifold.

So you are telling me this one won't survive with a mount added , that's a stainless steel stud in there, at worst the stud would break off, but I can always put another stud and coupler nut then build a bracket to come out to the other bracket or I can could come off those two holes on the side of the cylinder where the stock exhaust bracket attaches to if need be.

 

[kevbo]

That chamber weighs less than the cast aluminum ones do. I would try it, like you said theres not much to lose at this point.

 

[WFO Speedracer]

That chamber weighs less than the cast aluminum ones do. I would try it, like you said theres not much to lose at this point.

This is what I am thinking as well , somewhere around her I have several pieces of foam I pulled out of A 3D I could make a cradle out of as a backup plan.

 

[WFO Speedracer]

This got me thinking back a few years when people were putting 650SX exhausts on Superjets , none of them had added mounts either.