I cut them off with a small band saw. If you want to be able to clean them, weld in a 2 inch vband plug at each end. For me I will back flush it and chemically clean if it becomes nessary. I think from memory the heat exchanger guy told me it will do 1500 HP easily, so you have plenty of room...

I cut the ends off with a band saw. Very easy.
I will have it all welded up tomorrow. I will post pictures. I had the last one under the engine in my boat, but I'm moving it to the side to be able to service it. The last one leaked as I never pressure tested it. And I didn't chemical clean it. My bad... honestly guys, these things work awesome, cheap to buy, very high quality part. FAR higher quality than a heat exchanger. They are designed to take 650 degree C exhaust gas at 45 psi for a million- five kilometers... And the fab is easy...just get one and start, you will figure it out. Just make sure you pressure test and chemically clean it...iI added pictures of the boat and engine do you know in real...and that hand built 29 foot Vee is probably the close to the best in the world. The hull weight 800 kgs and is built like a work of art with 4 stringers and a full sheet of ply crossways every 24 inches, with glass over diagional teak...Jas

Hey Jas........It's wonderful to see someone like yourself figure out alternative ways to the high priced closed cooling market......your choice of a dd15 erg cooler which can handles far superior heat temps & pressure coming from big rig diesels .......with some modifications, seems like any hi perf. marine engine can be closed cooled comfortably.....and to think, I priced a monitor closed cooling system for my twin 572's for over 5K!!........and their backordered till Spring......
The boat, Hand built 29'?....what beam? ....great looking vee!......did you pull a mold or your design?......is that the 1200hp you speak of?........where do you race out of?..........very interesting, all of it!!

I really am waiting for the pictures, this is a good idea. When I rebuild i figure I will be around 600ish HP, sounds like I could make this a full system. What did it come off of exactly?

Exhaust Gas Recirculation coolers come off big rig diesels.......cools the exhaust gas going back into the manifold.

Here is a pic of it almost finished

Jas.....Pics didn't come through.

So you`re using something designed for exhaust gasses and filling it with salt water? I imagine most are doing closed cooling because of salt water .. salt water eats aluminum for breakfast, doesn`t seem like a long term solution.

Dan, I believe the whole thing is made out of stainless.