A "V" clamp would be ideal....BUT, the 2 different angles of the riser vs tail pipe would make that some what difficult, (not saying I couldn't weld in a 4" OD wedge) I'm gonna leave it as is for now and let my first time out decide what if anything else needs to be changed. With an IR Heat Gun and a portable Pyrometer in hand clamped to the Hump Hose, a good hard long run at WOT, that'll either make or break it, but thanks for your idea.comment, always open to the thoughts of others.

Follow up on class6's thoughts and comments...................

Ok, 10 cups of coffee later and lots of time to contemplate "class6's" ideas, I think it's a mod to my current design worth looking at. There are allot of positives in going to a "V" Clamp vs my temp limited Hump hoses even with the fiberglass hi-temp packing I was going to install to protect the Hump hose, it's still a risky way to do it. So here's what I'm looking at as a possible "Plan B" in design. Only reason on the fiberglass packing is to keep hot gases from coming into that open area between the riser extension and the tail pipe (tail pipe water elbow not shown, but its there)...............

Thoughts, comments as always appreciated...........

Flashback Thursday................

One of you guys had mentioned a mod you did on your exhaust by placing an extension tube onto the risers center 2 3/4 exhaust pipe......... who was that ??? As I've got a few questions, your brilliant idea sorta mirrors what I'm doing but at far less trouble and work compared to what I've got going here............I'm rethinking/having second thoughts on what I'm doing here with this project.........

Thanks

Perfect. I don't think you will need the 1500* packing. just gasket between the coupling. look at some dodge diesel sites. there are some gaskets for the turbo to down pipe gaskets that would work great

Or check CMI's website

Thank you for that info, I'll check it out......

Yup CMI sells and uses a "rope gasket'" under the V-clamp connecting the header to the tailpipe.

I'm leaning towards a flat gasket, copper, stainless, graphite etc. Being this is a one-off design, I found a high temp ring gasket at Mc Master Carr that will fit the V-Clamp flange faces, it's .06 thk and a Graphite Composite on Stainless with a temp rating of 850 Deg. I think that'' work great and only $3.99 each, now that's a deal !!!!!!!!

Just got done with these:

Here is one of the V-Clamp Flange adapters prior to welding onto the riser. I flared out the end for welding onto the riser since it reduces allot of the gaps if trying to weld it onto the base riser diameter which is a little out of round where as the high rib above the riser diameter is very round and a perfect mating fit for welding. It has a 4 degree slash cut on the exhaust exit end for the flange to be welded to so it'll match all the weird angles to keep it lined up with the tail pipe which also get one of these adapters so if I do everything right (LOL) I should have a pretty square fit on the V Clamp flanges.

To maintain alignments and not make the riser any taller by installing a wedge, this would be the cut line to get things back in line. This is "3 degrees" x 6" in length and leaves the flange at .187 on the right side (not acceptable in my book). It would also remove allot of the weld from the ID of the riser exhaust pipe causing more issues/work. So my plan goes forward using a couple of 100% Stainless 4.00" ID V Clamps. I'm currently setting up my Tig/Jig welding table to align and clamp up parts to make that 3 degree change at the V Clamp with no cutting needed on the flange. If any one is looking for some beautiful V Clamps, let me know as the ones I bought (unlike others) are 100% 304 Stainless Steel and incorporate a male/female locking flange, they are a work of art.

More pics next week, got to catch up on the neglected "Honey Do List".........

Sunday progress...........

One down one to go:
EDIT ADDED:
I still have to add the "V-CLAMP" flange. This is just with the 3" OD 304 Stainless exhaust pipe extension. V-CLAMP Flanges will be tack welded in the boat assembled to the riser to assure proper alignments