Engine cooling

[ThePiglet]

Hi,

 

I've just bought an unfinished project 27ft Springer from a chap who was mid-fit of a Lister Petter AC2W engine.

 

His plans were to direct raw-water cool it and I've decided to go along that road too for now, most likely in the future converting it to indirect via heat-exchanger.

 

My question is, on the AC2W exhaust manifold there are two holes that appear to be 3/4" BSP. One on the top and one on the bottom. The botom one is closest to the manifold exit. At the moment they are holes with nothing in and appear to have some corrosion (rust type) but no soot. Are these likely to be for a water cooled jacket on the exhaust?

 

As I've been witing this, I've just though that blowing through one and plugging the other would tell me if it's sealed or not. I'll try that later today.

 

I'm sure I'll have many more questions as the weeks/month(/years!?) go on

 

John

[RobinJ]

My question is, on the AC2W exhaust manifold there are two holes that appear to be 3/4" BSP. One on the top and one on the bottom. The botom one is closest to the manifold exit. At the moment they are holes with nothing in and appear to have some corrosion (rust type) but no soot. Are these likely to be for a water cooled jacket on the exhaust?

It sounds right, normally water is forced through the manifold in the opposite direction to the exhaust, so hot water rises from the end opposite to the exhaust.

Some systems use a primary cooling of the engine, which is then cooled by secondary raw water with a heat exchanger exhaust manifold system, others simply direct cool the engine and exhaust manifold. Either system can then be expelled through a separate outlet or injected into the exhaust through a swan neck.

Boils down to whether you have one or two pumps!

[ThePiglet]

It sounds right, normally water is forced through the manifold in the opposite direction to the exhaust, so hot water rises from the end opposite to the exhaust.

Some systems use a primary cooling of the engine, which is then cooled by secondary raw water with a heat exchanger exhaust manifold system, others simply direct cool the engine and exhaust manifold. Either system can then be expelled through a separate outlet or injected into the exhaust through a swan neck.

Boils down to whether you have one or two pumps!

Proper job. I blew through it today and there doesn't seem to be any through to the actual exhaust.

The engine only has one pump, so it'll be direct raw-cooled and directed out of the boat via the second hole in the bottom.