Standpipe Exhaust

Brian Timmins asks

Was Whitby's exhaust the bronze/copper standpipe design? I have this design and it appears original (including a molded fiberglass cover for the output). It's in fine shape still, but it came close to being trashed a few years ago when I changed my manifold and exhaust flange. I've had problems with exhaust systems on other A4 equipped boats in the past and I'm sort of amazed that this system might have lasted since 1972.

Has anyone taken one of these apart and drawn up it's design and how to build one? It appears fairly simple from the outside, but I'm curious as to the internal fittings, most especially the end of the actual exhaust pipe inside the water jacket and the end of the water injection at the top. There must be some magic there since I've cranked my engine for quite a while without it starting and I've never had any water get down to the manifold or the #4 cylinder. There must be something that keeps the water from going straight into the exhaust pipe. (water injection flows down and exhaust pipe flows up, both perfectly in the middle of the larger standpipe)

I'm curious since I know nothing lasts forever. This system appears original from almost 30 years ago. If I've ever got to replace it, I'd like to replace it in kind and not have to worry about it for another 30 years.

Has anyone tried this exhaust on an engine other than an A4? I'm so impressed with this design that I don't understand why water lift mufflers were ever designed!!

John Birch replies

Whitby built these mufflers and installed them on their A-37's too. Our A-37 Sunstone, KC 65, has a Westerbeke 4-107 and uses such an exhaust identical to the one that was on our A-30 Wind Rose, KC 544. I would not be surprised if Whitby also put them on the Whitby 42 and 45s either. It is an elegant yet simple design, the centre hot exhaust pipe goes nearly to the top inside and the water and exhaust mix and exit about 70% of the distance to the top out the side of the muffler water jacket leaving all the down stream piping fairly cool. They are not welded together but soldered, and if you ever remover the pipe to change the iron exhaust flange at the Manifold do be careful not to apply any twisting motion to the internal bronze pipe which comes off the iron elbow near the manifold flange or you will sheer the solder on the pipe where it enters the water jacket.

The jacket and pipe are, I believe, bronze and not copper and when I sheered the solder seal ( on Wind Rose's muffler ) and took it to a machine shop, the first thing the machinist said was "wow, that is worth a bundle, don't ever think of replacing it because it is bronze" - he put a torch on it and resoldered the pipe at the base to the water jacket and it was perfect.

When using a pipe wrench to remove or install, do be careful to pad the teeth so they do not chew up the bronze pipe (it is fairly soft and will mark or deform easily). If the exhaust iron elbow has failed it is often prudent to take it to a shop to get the iron flange off the bronze pipe but remember the thing is soldered together and too much heat applied will melt the solder. So do point that fact (that it is soldered) out to the machinist.

It is such a pain to get the whole thing back together and then find it is leaking - been there, done that. ;)

On iron elbows — do remember to use a black iron elbow and not a galvanised one as toxic fumes are released from the galvanising with the heat of the engine. The elbow is not cooled in the system and gets quite hot which is why the water hose runs up to the Muffler jacket. Many elbows are wrapped in asbestos tape too — yea asbestos, yea that kind of asbestos — so please do take appropriate precautions handling it.

Joel Lembo reports

I took my water muffler apart last year, It had a rattle in it. the 1-1/4 inch bronze pipe goes up about three inches from the top. it has a 2 inch bronze pipe cap sitting on top held there by four 3/16 inch square bronze rods soldered on, silver-soldered, I believe. The rods had corroded over time so the cap was not secure. I decided to scrap the old one and make my own. I went to the scrap yard and got the materials to make one out of stainless steel for $20. I welded it all up at work and it works very well and I dont have to worry about putting a wrench on it.

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