Aq271 fresh water cooled Manifolds

[Sam Jenkins]

Hi im thinking of converting my exhaust manifolds to fresh water cooling as I have a closed loop system on this engine already. Has anyone done this and if so is there much work involved if so where do the pipes run too and from from the manifold
Many thanks Sam

 

[Scott Danforth]

Can't do it, even if you bought new manifolds

You would need to double your heat exchanger size and the manifolds are too restrictive on the water side

Those are words direct from the chief engineer at Volvo Penta 12 years ago when I considered a full system on my AQ271c when I worked for the heat exchanger manufacturer supplying VP and Mercruiser

Hence the reason VP released the neutrasalt system.

 

[Sam Jenkins]

Ahh ok was an idea I had to try and preserve the life of them.
I do flush them out with fresh water on the mooring by shutting off the water intake and plugging a hose pipe into the suction side of the raw water pump via a fitting. hopefully this will preserve the life of them.
What would you expect the life span of them to be the boats in the water 6 months of the year and then dry stored over the winter months. I allways service and winterise the engine at the end of the season
Cheers

 

[Scott Danforth]

you should be getting 10 years or more with your manor of flushing

you could also get the neutra salt system, as you come into the slip, just hit the button for about 1 minute until you shut down.

 

[Lou C]

I keep my boat in salt water all season (6 months) only flush at the end of the season and fill with antifreeze with corrosion inhibitors when winterizing.
I’ve never had a failure and have changed them usually @ 5-7 seasons (OEM batwings). Don’t know how far I could have gone to the point of failure though.
Now I have the later 2 piece style and my plan is to remove the elbows & inspect at 5 seasons; if the manifolds look good & pass the Acetone test I may re use them with new elbows. If the sealing surfaces don’t clean up though time for new for both.