Is a water-cooled exhaust manifold worthwhile

[JohnB]

Our current quite mature engine has served us well but is going to need a serious rebuild very soon and we don't want to be doing that when we should be travelling.....

 

Sooo.    We have an ex forklift engine to overhaul and then do a direct swap with our present unit. We are also doing the "tweaks" to make it properly suitable for marine use. The 3HD46 (the marine version of the D3.152) was fitted with a manifold cooler and, at this point in process we could add this into the build....

 

Given that we have had no issues with the existing set up (an expansion box hung from the roof of the engine room with a flex coupling onto the exhaust manifold) I am trying to decide on what is to be gained from the necessary extra modifications.

 

Does anyone have any observations or advice please ?

 

[dmr]

If you plan to do quite a bit of engine running for battery charging only then it might help the engine to warm up. Our JD3 struggles to get up to temperature on a cold winters day unless we have the Travel Power/washing machine on. On the other hand if your cooling system is a bit marginal then cooling the exhaust will put a bit of extra strain on the cooling system.

 

...............Dave

[Chewbacka]

13 minutes ago, JohnB said:

Our current quite mature engine has served us well but is going to need a serious rebuild very soon and we don't want to be doing that when we should be travelling.....

 

Sooo.    We have an ex forklift engine to overhaul and then do a direct swap with our present unit. We are also doing the "tweaks" to make it properly suitable for marine use. The 3HD46 (the marine version of the D3.152) was fitted with a manifold cooler and, at this point in process we could add this into the build....

 

Given that we have had no issues with the existing set up (an expansion box hung from the roof of the engine room with a flex coupling onto the exhaust manifold) I am trying to decide on what is to be gained from the necessary extra modifications.

 

Does anyone have any observations or advice please ?

 

I would suggest you consider cooling.  The engine in a boat is often in a confined not very well ventilated space.  A water cooled manifold will reduce the engine space temperature by having a cooler manifold and exhaust pipe and silencer, this will improve belt life and possibly alternator life.

[BEngo]

If the 'new' engine manifold  is not connected identicallly to the existing one, you will have to bugger about with the water and exhaust pipes etc. when you do the swap. 

I would desire a water cooled manifold but might forgo it if the ancillary connections were a major job.

Only you know your current set up well enough to decide how much more difficult the swap will be with a different manifold.

 

N