Exhaust manifold drains

[seatek]

Continued from "Volvo Penta starter rebuild"

The only way I could figure water getting down in the starter nose cone was from removing the drain plugs to winterize and they are a royal PITA to remove. No other leaks evident anywhere.
I decided to install drain valves with tubing to route the water away from the starter area.
Njlarry wanted a pic, so here it is.
The brass valve is similar to those used on radiators.

I'm going to re-do it again next year differently as I think that brass valve is the weak link.
Any-one else have a solution?

 

[Don S]

Re: Exhaust manifold drains

The big problem with any kind of valve, is that it can get plugged up by rust, mud, crud, and other crap inside the manifolds water passages.
Just throw a plastic bag over the starter when you drain the manifold.

 

[njlarry]

Re: Exhaust manifold drains

Thanks for the pic. You're right, they are a PITA to remove and replacemants are not always easy to find. How did you tap/thread the manifold to take the fitting? What part did you use for the petcock? I would love to add them. It would shorten my winterization time at least 10-15 minutes.

 

[Don S]

Re: Exhaust manifold drains

Replace your manifolds njlarry, the new manifolds come with a 3/4"NPT threaded hole in the end. Only the old manifolds had the rubber caps that OMC used. No need for fittings and valves for reasons mentioned above.

 

[Bondo]

Re: Exhaust manifold drains

The big problem with any kind of valve, is that it can get plugged up by rust, mud, crud, and other crap inside the manifolds water passages.

Ayuh,..........

I predict Frozen,+ Busted manifolds in your future.........

 

[njlarry]

Re: Exhaust manifold drains

Why could it not be probed same as the block petcocks?

 

[Don S]

Re: Exhaust manifold drains

I usually have to dig the stuff out of there with a screwdriver. If you have fittings and elbows and valves in the way, how you going to get a screwdriver (or anything heavy enough to break the stuff loose) thru a small curved opening.

 

[seatek]

Re: Exhaust manifold drains

I usually have to dig the stuff out of there with a screwdriver. If you have fittings and elbows and valves in the way, how you going to get a screwdriver (or anything heavy enough to break the stuff loose) thru a small curved opening.

Njlarry, I'm inclined to agree with Don and Bondo.

My situation is somewhat unique in that the boat is not wet slipped and the engine gets flushed after every use and I'm also a mechanic (not marine).
Every two years, the entire system is flushed with a solution of "iron out" and trisodium phosphate with a raw water recirculating system I dreamed up. This cleans all the crud and stuff out of the manifolds and risers.

Having said that, I'll probably change out that valve, put an elbow then long hose and valve at the end of the line next year. I'm fortunate that I have easy access to an air compressor and water to backflush if neccessary.
My manifolds were already 3/4 pipe threaded with a reducer and 1/4 drain plug so no tapping was needed.

If your boat is wet slipped, or you do not do the above, I strongly recommend you follow Don and Bondo's advice.

 

[njlarry]

Re: Exhaust manifold drains

I know the great value of Don's and Bondo's experience and advice.
I didn't notice your engine is much newer than my '95 that is not tapped. Those plastic caps are cra* My manifolds are old but in perfect condition so I'm a way from replacing them but when the time comes I'll look forward to a set up like you describe. I always probe but never trust that I can probe all the way so like to add auto antifreeze.
Thanks to all.

 

[Don S]

Re: Exhaust manifold drains

Don't expect pouring antifreeze into a partially water filled manifold to work. The AF and water will not mix that easily.