MD 7A Exhaust

Oct 30, 2019
67
On my MD 7A, the cast iron piece that mixes the engine exhaust with the cooling water, and which connects the exhaust manifold to the hose leading aft to the muffler, has rusted out. According to knowledgeable welders, it is beyond repair. Has anyone faced a similar situation? Is it possible to find and purchase a replacement? Has anyone had a substitute system fabricated?

Any help would be appreciated.

Many thanks,

Clint Edmonds,
Gladwyena
 
Oct 30, 2019
1,459
Clint,
I have a Yanmar, not a Volvo, but I think you could do something similar to this. I made up a new piece using black pipe and brass fittings, with a home-made flange to the engine:

I tacked it together with a gas welder and had it professionally welded at a shop. (I added a short piece of threaded black pipe, not shown in picture, to allow a coupling joint to the brass piece). The cooling water tube was brazed to the brass exhaust piece. A "Y" fitting and reducer could be used, but I could not find one locally.

The 'hot' section was wrapped in insulation.

This picture shows the cooling water inlet to the main exhaust.

So far it's lasted 4 1/2 years, with lots of use. If I have to do it again, I'll use all stainless steel pipe.

Peter
#1331 'Sin Tacha'
 
Oct 30, 2019
67
Thank you Peter,

I have asked a local blacksmith to fabricate a substitute for me. He is going to do it in stainless. I will print off your pictures and show them to him. I am sure that they will help.

Changing the topic, we communicated some time ago about window seals for a Series 3 Vega. I found a firm in Tukwila, Washington, called Perfectfit. The seal installed easily and the price was reasonable - in case your ever interested.

Kindest regards and thanks for the info,

Clint Edmonds,
Gladwyena
 
Oct 30, 2019
1,459
Clint,
Thanks for the tip on the supplier. I'll keep that on file.

Glad to hear you have the exhaust sorted. I think stainless is the answer.

Peter
#1331 'Sin Tacha'
 
Nov 2, 2008
10
Hi,
I am working on it right now. To buy exhaust riser - no problem, they are available so far. Expensive though. Around 400 can. with gaskets.