New engine, need help with cooling system

[MarkHez]

Hi all, the Perkins 4108 that I had in my boat (27ft cruiser) was beyond economical repair, so I fitted an Isuzu 3KC1 that I scavenged from a 360 digger.

 

Currently I am using the diggers radiator and pulley driven fan, but obviously this is not the most efficient method in a small boat engine bay. The perkins used a tube and shell heat exchanger and wet exhaust, unfortunately I sold all this with the engine (for much too low of a price!). As I can see it, I could either use raw water cooling (not really too happy with that idea), or use a heat exchanger system which would also allow me to run the bypass circuit to a calorifier.

 

So my main question is, where can I find a reasonably priced heat exchanger? Any tube and shell heat exchangers with the word "marine" in the name are ridiculously expensive (upwards of £300 for the size I'd need) whereas a plate heat exchanger of the same thermal properties is about £30.

 

Has anyone used a plate heat exchanger with raw water before now? The only thing I'm worried about is clogging of the cooling channels, obviously I'd be using a strainer in conjunction with it, but I'm still not sure how easily it would get blocked.

 

 

If anyone can weigh in on this, it would be very much appreciated.

 

Thanks

Mark

[Alan de Enfield]

Hi all, the Perkins 4108 that I had in my boat (27ft cruiser) was beyond economical repair, so I fitted an Isuzu 3KC1 that I scavenged from a 360 digger.

 

 

 

 

There is a huge difference between a Perkins 4108 and an Isuzu 3KC.

How are you managing the gearbox, drive and propeller set up ?

[MarkHez]

 

There is a huge difference between a Perkins 4108 and an Isuzu 3KC.

How are you managing the gearbox, drive and propeller set up ?

 

I drilled and tapped the flywheel to take an R&D drive plate (with a spacer turned down from 10mm steel to bring it further away from the flywheel) and made my own bell housing to mate the engine to the original velvet drive 1:1 box.

[Bee]

Personally I would continue using the diggers rad and fan unless theres a good reason for getting rid of it, is the running temp ok? Heat exchangers, manifolds pumps and all the other stuff is expensive. Well done for connecting up the flywheel to the gearbox and shaft etc, that can be challenging engineering.

[MarkHez]

Personally I would continue using the diggers rad and fan unless theres a good reason for getting rid of it, is the running temp ok? Heat exchangers, manifolds pumps and all the other stuff is expensive. Well done for connecting up the flywheel to the gearbox and shaft etc, that can be challenging engineering.

 

The reason for getting rid of it, is I can't put the cockpit floor in place while cruising, as the radiator sticks up through it by 2" !

 

I'd be going with a dry (lagged) exhaust, just water pump from the seacock, through a strainer, through the gearbox oil cooler, through a plate heat exchanger for the engine, then back out through a skin fitting.

 

Plate heat exchangers can be had for £30-40 quid, which is why I need to know if it would be suitable, or if it would block up too easily having raw canal water pumped through it!

[Neil Smith]

Could you drop the rad down 2" or if not get a lower rad from a breakers yard.

 

Neil

[MarkHez]

Could you drop the rad down 2" or if not get a lower rad from a breakers yard.

 

Neil

 

I could, yes, if I were to make a new duct out of fibreglass. It would also require fitting a large bilge blower to keep air flow moving through the engine bay from outside.

 

I would still prefer to ditch it though.

[Neil Smith]

I think the plate heat exchanger would clog up because you cant put inhibitor in it, I use one to cool beer after the boil but have to soak it in caustic soda every couple of brews or it becomes less efficient.

 

Neil

[BD3Bill]

Maybe a pair of smaller radiators fitted with Kenlowe type electric fans ?

 

I share the view that any H/E will soon block up, which is a shame as v efficient idea.

 

Could you fit a tank to pump canal water in/out and hook up the H/E to that? A Calorifier would work, sort of in reverse though, if you know what I mean?

 

 

Impressed with your grip on engineering btw

[cuthound]

If you have sufficient space on the bost you could use a plate heat exchanger with one side connected to the engine and one side connected to a remote radiator.

 

I have cooled large 2000kVA generators like this, with the engine in the basement and the remote radiator 10 stories up on the roof.