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
https://cimg4.ibsrv.net/gimg/www.off...dd68225671.jpg
https://cimg5.ibsrv.net/gimg/www.off...3548e3d218.jpg

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.

https://cimg1.ibsrv.net/gimg/www.off...d3ef3e8726.jpg
https://cimg8.ibsrv.net/gimg/www.off...d1bf0f6551.jpg

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.

Yep it's 100% stainless. It's designed to have water one side, and 600 deg C exhaust gas at 60 psi on the other. The build quility is far superior to and marine heat exchanger you will ever buy... Jas

I may be missing something but do I see 4-6 holes? What are those big holes on the top?

Wouldn't in be one in for raw water, one out for raw water and the same for engine water?

Do you have a sketch on how you are hooking this up?

2nd on the sketch layout.

Big holes on top are engine water in and out. Fittings to be welded on once engine is in and orientation is figured out.

-12 fittings on front are seawater to exhaust manifolds.

32mm fitting on the back is seawater in.

2 X 25mm fittings at back, 1 for a pressure releif valve as it's making 35psi water pressure. That will dump on top of the drive...
1 for a feed to fill my balast tank up front via a tap the co driver controls. When it's opened, the pressure releif valve will close or reduce at least...
Jas

Heat exchanger
 

https://cimg1.ibsrv.net/gimg/www.off...4e92605559.jpg
https://cimg2.ibsrv.net/gimg/www.off...ddd3cbf91b.jpg

Starting to see the whole picture now!....have you figured out the placement the glycol tank & circulating pump yet?.....can you tell me the length of the cooler & the end dimension ~3" x 3" ??? or so.
Seeing a lot of different coolers & Trying to figure out what cooler would be best for my setup.....I'm running n/a 700 hp BBC's .......what dd15's would suit my needs?.....No doubt, there's a bit of
fabrication involved probably not for the non-wrencher DIY-er, but I do weld (a bit) never tig on ss before, but I can throw it down & have a go at it if I choose .....to me, running in the ocean and
having already eaten up 2 pairs of Imco power flow manifolds is not cheap.......I can pay 5K on a pair of CC systems from Harden - or- go cheap on the $$ and big on the labor try!

I understand now. I looked on E-bay and there are a few of these there, it would be nice when I re-power. With Scippy, can you post dimension? I will only be around 600HP NA.

A smaller one would work good as a oil or trans cooler .

I wonder if the larger one would work well enough to run the engine and exhaust?

I believe a full system is engine and Manifolds, but not risers.

I could see the need for a full system in a cruiser style boat where access is limited to the manifolds. In a performance application where the boat is on a trailer , a half system is sufficient. A 10 minute flush with saltaway cleans out the coolers and the exhaust.

I'm curious if anyone has done testing with the standard engine water pump vs a high flow unit such as flowkooler makes in a closed cooled system? Not the seawater pump, I'm talking about the pump that will have the glycol going through it.

I'm not sure if it would do anything or not? Maybe make it worse? who knows?

A high flow pump can only help. Anything to increase flow velocity and get to a Reynolds number of an RE>3500 and try to maintain an RE>4000 to get to or maintain turbulent is a good thing when cooling.

Hi Bud, Can you explain all those RE numbers. Haven't heard that one before

It's a calculation used to distinguish between laminar and turbulent flow of a fluid depending on it's viscosity. Usually for pipes and what size to used for efficient cooling. I'm loosely using it in cooling terms of an engine block. Laminar flow is when you turn your faucet on slowly and it smoothly comes out of the faucet. Then you get to the point where all he// breaks loose and it's not a nice stream. There you have turbulence and better cooling.
https://resources.system-analysis.ca...turbulent-flow

Jas can you give me the length & square end measurement to your dd15?........I found one 20"-5/16's long by 3" x 3" square at the ends.
or give me what capacity a DD15 cooler cooler would work for a N/A 572 cu. in. BBC 700hp?

It's about 750mm long and 4" X 4 1/2" in size. But that will do 1200hp, so your smaller one will be plenty for 700na easily...but count how many tubes and how long and call a heat exchanger guy and ask him if its enough... Or compare with a commerical available one... Jas

So your exchanger (cooler) 750mm (almost 30") can you tell me how many tubes yours contains?....it will give me an idea relative to my engine hp

Here is the picture with the tails installed... I am installing the cooler beside the engine, if you have it in front of the engine, your tails will be quite different... Jas
https://cimg1.ibsrv.net/gimg/www.off...39c56aa39.jpeg

Jas .....Appears you can fabricate (nice job) I don't think that would be the same for me...Buying a used Detroit dd15 cooler is a cheap first step especially if you can do all the fabrication yourself
but in my case, having someone else to (a fab shop) do all the work would probably go over the cost effectiveness of it .....I love the idea in principle that the dd15 has a much better cooling capacity
then a mfr. marine closed cooling system (shell & tube) but just wondering where this would end up for me if I get my feet wet.........post up (pic) as you get to completion, seems it's going in the right
direction.

https://cimg2.ibsrv.net/gimg/www.off...bb2f11170d.jpg
here is the finished unit
https://cimg3.ibsrv.net/gimg/www.off...429cb9c52e.jpg
https://cimg4.ibsrv.net/gimg/www.off...75779586dc.jpg

Jas that picture is worth a 10000 words!.....where is the tank for filling the glycol?

It's on the transom...

Gotcha, I see it now ....I love all the stainless and chrome in the engine housing!....mighty purdy! ....if you ever happen to build another couple of them let me know!

Just to follow-up on installing CC on my twin engines, I spoke with Marc (BAM) and inquired to buy his closed cooling setup pictured in post #11.... he sent me numerous pictures and measurements, but advised that his CC system was way over kill for my setup. After measuring it didn't take long to realize he was right, just want to thank Marc for taking the time and trouble for getting it down off the shelf to satisfy my persistence. He told me to call .... Brandon @ Mr. COOL he advised they don't make a CC system for a BBC engines....really???..I guess he knows!
.

Mr Cool doesn’t make closed cooling for big block engines??

No problem at all, once I had taken the time for the pix I was able to list them in the Swap Shop instead of being lost in the archives :)

Now on to the next - my old stuff must go

Words right out of his mouth ... No. (BBC)

This one is for the 7.4, seems they would have some that would work.

Attachment 577591

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Just a little undersized for my 9.4L (572 cu. in.).....taking a look at a Merc 454/502 exchanger liker TomZ