Volvo MD-7a muffler

[Wallace Edwards]

I am the original owner of 1978 CD30c #81 with Volvo MD-7a inboard. The original muffler has developed several small holes. The local yard (Ross Marine Charleston SC)in communication with Volvo Penta has determined that this was not the standard stock muffler and thus cannot supply a replacement. Does anyone know the origin of these mufflers and a current supplier? Was this perhaps an item custom built by Spartan?
Also the yard welder is hesitant to attempt a repair for fear of going from bad to worse. Are there any suggestions for repair or an alternate muffler.
Thanks,
Wally Edwards CDSOA #319
"Spoondrift II"
Augusta, Ga.



wedwards@mail.mcg.edu

[John R.]

The stainless CD mufflers were custom made and are a problem. The welds will fail in a stainless sheet metal muffler canister because the welding process destroys the passivity of the seam. Just use a fiberglass waterlock unit such as Naqua Lift or similar or you can use a plastic unit such as Vetus. You will need to make modifications in or near the engine compartment to mount these type units. It is not a big deal you simply need to make a secure mounting platform, glassed to the hull is best. Keep the muffler located as close to the centerline of the boat as possible. Also be sure to allow plenty of clearance for movement of the engine. The engine shifts position fore and aft considerably when in gear and generating thrust. Your yard should be able to help you out with the retrofit if you don't feel you can do it. By all means the welder was correct, don't attempt repair on the old can, just replace it.

I am the original owner of 1978 CD30c #81 with Volvo MD-7a inboard. The original muffler has developed several small holes. The local yard (Ross Marine Charleston SC)in communication with Volvo Penta has determined that this was not the standard stock muffler and thus cannot supply a replacement. Does anyone know the origin of these mufflers and a current supplier? Was this perhaps an item custom built by Spartan?
Also the yard welder is hesitant to attempt a repair for fear of going from bad to worse. Are there any suggestions for repair or an alternate muffler.
Thanks,
Wally Edwards CDSOA #319
"Spoondrift II"
Augusta, Ga.

[Wallace Edwards]

Thanks John for the prompt reply.
Wally

The stainless CD mufflers were custom made and are a problem. The welds will fail in a stainless sheet metal muffler canister because the welding process destroys the passivity of the seam. Just use a fiberglass waterlock unit such as Naqua Lift or similar or you can use a plastic unit such as Vetus. You will need to make modifications in or near the engine compartment to mount these type units. It is not a big deal you simply need to make a secure mounting platform, glassed to the hull is best. Keep the muffler located as close to the centerline of the boat as possible. Also be sure to allow plenty of clearance for movement of the engine. The engine shifts position fore and aft considerably when in gear and generating thrust. Your yard should be able to help you out with the retrofit if you don't feel you can do it. By all means the welder was correct, don't attempt repair on the old can, just replace it.

I am the original owner of 1978 CD30c #81 with Volvo MD-7a inboard. The original muffler has developed several small holes. The local yard (Ross Marine Charleston SC)in communication with Volvo Penta has determined that this was not the standard stock muffler and thus cannot supply a replacement. Does anyone know the origin of these mufflers and a current supplier? Was this perhaps an item custom built by Spartan?
Also the yard welder is hesitant to attempt a repair for fear of going from bad to worse. Are there any suggestions for repair or an alternate muffler.
Thanks,
Wally Edwards CDSOA #319
"Spoondrift II"
Augusta, Ga.

wedwards@mail.mcg.edu

[Ken Cave]

When I purchased my CD 28, I had the local yard go through the whole boat to insure that it would work on extensive trips. The first thing they did was to take out the original muffler and install a Vernalift type muffler (Actually it looks like a twelve inch round pipe)

As it is made of fiberglass, I should last as long as the boat lasts.

Mounting? All my mechanic did was to attach the muffler with two strips of vinyl plumbers tape right to the hull with half inch stainless screws.

An easy fix, and won't cost a fortune either!!

Ken Cave
CD 28 #227
Anacortes, WA



bcave@whidbey.net

[Wallace Edwards]

Thanks Ken. Is this on the MD-7a, I thought the CD28 had a different engine?



wedwards@mail.mcg.edu

[Ken Cave]

Most of the CD 28s that I have seen (and that ain't a lot) have had the MD7A engine, and, according to the Volvo folks in England, there are thousands out there that just won't quit!

If you can't get parts for yours, try calling D B Marine at 01628 520564 (be sure to dial in 001-44 before the above number)or try them at www.dbmarine.co.uk

Mark Sinclair is the person I have worked with-even with fix-it booklets for my new 2020. Usually have the stuff within two weeks from ordering-mostly less! Parts are usually a whole lot cheaper also

Hope this helps

Ken Cave CD28 #227
Anacortes, WA



bcave@whidbey.net

[wallace edwards]

Thanks Ken



wedwards@mail.mcg.edu

[Larry McAnally]

Wally,
I echo the advice from John and Ken. I had a welder attempt the welding repair. It was unsuccessuul and costly$.
I then replaced with a fiberglass Vernalift as Ken suggested and have been good for over three yrs.
Vernalify is from Centek Industries 800 950-7653.
The # for the unit I used is 07127198 and is not as large as the one Ken described. I used part of the old muffler (pipe)to manufacture a fitting to connect to the manifold and adapt to the small hose.
As Ken said it should last forever, and no drips.
Good luck!
Larry McAnally
CD30 Intowishin
Destin Fl



larrymac@gccoxmail.com

[wallace edwards]

Sounds like good advice!



wedwards@mail.mcg.edu