How many heat exchangers do I have?

[CalicoJack]

This months PBO "How to service your cooling system" shows a Bowman heat exchanger, which looks similar to the one that I have on my boat. The engine is a Perkins 4108, which runs a sealed ie a fresh water cooling system. It also has water cooled TMP gearbox on the raw (salt) water side. However, there is a large cylindrical tube behind the engine, mounted above the gear box into which goes both salt and fresh water; hopefully they remain separate. This I have always assumed to be the heat exchanger, although it is not clearly marked with a manufacturers name, but does this mean that I have two heat exchangers? One the cylinder and the other the Bowman unit attached to the exhaust manifold.

 

[GrahamM376]

It appears you have two, maybe the one above the gearbox is a separate one for gearbox cooling.

 

[Tranona]

Think it is only one heat exchanger. The other is the water cooled exhaust manifold.

 

[VicS]

This months PBO "How to service your cooling system" shows a Bowman heat exchanger, which looks similar to the one that I have on my boat. The engine is a Perkins 4108, which runs a sealed ie a fresh water cooling system. It also has water cooled TMP gearbox on the raw (salt) water side. However, there is a large cylindrical tube behind the engine, mounted above the gear box into which goes both salt and fresh water; hopefully they remain separate. This I have always assumed to be the heat exchanger, although it is not clearly marked with a manufacturers name, but does this mean that I have two heat exchangers? One the cylinder and the other the Bowman unit attached to the exhaust manifold.

Your attached thumb nail only opens to another similar sized picture for me. Can you post a decent sized image.

Are you sure that the item at the front of the engine is in fact a heat exchanger? Do salt water pipes run to/from it? Or is it just a head tank for the freshwater coolant ?

Or as Tranona suggests are you looking at a water cooled exhaust manifold, along the side of the engine

 

[Jcorstorphine]

My spin on the engine is as follows.

There is some form of tank at the front of the engine which I think is the engine freshwater heatexchanger. The exaust mainifold is water cooled and not a heat exchanger. The tubular asembly at the rear of the engine seems to be cooled in series with the fresh water tank at the front and it would appear to be an oil cooler for the gearbox but is bigger than normal.

see this link for pic of front heat exchanger

https://www.bing.com/images/search?...9e641d874b7e37b4ab594b4c3de13042o0&ajaxhist=0

 

[CalicoJack]

Thanks for that. You are right, there is a header tank at the front, and the cylinder at the back must be some form of heat exchanger as salt water goes in and out of it, prior to going into the exhaust. Others have suggested that there is a water cooled exhaust manifold on the fresh water side, which makes sense. Does anyone recognise the cylindrical heat exchanger and who made?

 

[Jcorstorphine]

Thanks for that. You are right, there is a header tank at the front, and the cylinder at the back must be some form of heat exchanger as salt water goes in and out of it, prior to going into the exhaust. Others have suggested that there is a water cooled exhaust manifold on the fresh water side, which makes sense. Does anyone recognise the cylindrical heat exchanger and who made?

It could be a Bowman or Thermax if it has the hemispherical domes on each end but I cant see from the pic. See this link for Bowman type

http://www.asap-supplies.com/engine-spares-gearboxes/oil-coolers-accessories/oil-coolers

 

[Billjratt]

That's the same configuration of 4108 that I have. The tube above the gearbox is the main heat exchanger .There is an oil cooler (raw water) above the starter motor and as already mentioned the gearbox cooler(raw again) - you may want to check the sacrificial hose connectors to that, as they are the only "anodes" in the system, and if you still have the original copper pipes fitted, they may need replaced. The bit at the port side is just a (fresh) water-cooled exhaust manifold.

 

[Baddox]

I cannot tell from the small photo, but if you have a turbo, it is likely that you will also have an intercooler heat exchanger.