Frame generators

[Wiggo]

Not sure if this has been asked before, but I keep coming across quite cheap diesel gennies. Unfortunately they are air-cooled frame gennies: has anyone managed to run one successfully on a boat? Could you wrap the thing in small bore copper pipe and pump water round it to cool it? Or would you be stuck with a noisy agricultural thing on the bathing platform?

 

[jfm]

Not sure if this has been asked before, but I keep coming across quite cheap diesel gennies. Unfortunately they are air-cooled frame gennies: has anyone managed to run one successfully on a boat? Could you wrap the thing in small bore copper pipe and pump water round it to cool it? Or would you be stuck with a noisy agricultural thing on the bathing platform?

Tricky. Haven't done the maths, but copper pipe cooling feels v unlikely to work, and you'd need to manufacture a PTO to drive the pump (or perhaps a 230v ac pump could be used, if it's ok to run the engine 10seconds before it gets going properly). The only way to get sensible noise levels from diesel genset is to have it in soundproof cabinet in soundproofed engine room. That means air cooling aint gonna work, sorry

 

[Wiggo]

Yes, that was my thinking, John. If you could work out how to cool it, you could stick one in a soundproofed box in the lazarette - I already have the fuel feeds in place from the port tank. You could run an electric water pump from either 240V or 12V and as it's designed as an air cooled lump it would take a while before it needed cooling water.

I doubt it will ever happen, more an intellectual exercise than anything, brought about by the vast cost difference between a marine genset (c £5k) and a building site frame job (c £200).

 

[Ifraser]

I've seen one...

last week I looked at a trader 38 with a view to buying.. the guy was doing exactly that..air cooled diesel genny in engine room.. I did ask if he had any cooling problems but he just said that if he did need to run it for any length of time he'd just run the bilge blower. I guess in the UK you may well get away with it given that these things should run in the desert in mid summer. Certainly his boat showed no sign that it was a problem. Assuming that you don't run the genny when the engines are running you can probably get enough air in there to do the job...Iain

 

[jfm]

last week I looked at a trader 38 with a view to buying.. the guy was doing exactly that..air cooled diesel genny in engine room.. I did ask if he had any cooling problems but he just said that if he did need to run it for any length of time he'd just run the bilge blower. I guess in the UK you may well get away with it given that these things should run in the desert in mid summer. Certainly his boat showed no sign that it was a problem. Assuming that you don't run the genny when the engines are running you can probably get enough air in there to do the job...Iain

Hmm, yep, from a cooling point of view that all makes sense. The genset couldn't be in a soundproof box, but I suppose if it were in the soundproof engine room with the doors shut it would be considerably quieter than on the bathing platform, and the noise might just be acceptable, or at least worth the £4800 cost saving.

 

[NorthUp]

soundproof

No reason not to build a soundproof box even when aircooled- just look at the compressors at any roadworks- the modern ones have been silent running for years now. Build a labryinth of soundproofing material, add a substantial 240v fan- remember that you need an outlet as well as an inlet for the air.
Or, find a ready made casing at a breakers yard, add your own fan, 'cos the compressor's was probably shaft driven from its own engine.
It will be heavy though.

 

[seamaster30]

Not sure if this has been asked before, but I keep coming across quite cheap diesel gennies. Unfortunately they are air-cooled frame gennies: has anyone managed to run one successfully on a boat? Could you wrap the thing in small bore copper pipe and pump water round it to cool it? Or would you be stuck with a noisy agricultural thing on the bathing platform?

You also need to consider the exhaust - Even with an extractor fan running, the area will get covered in soot within a short period of time.
I used to reverse a diesel car into a garage and within a year it was filthy in there.

 

[burgundyben]

more an intellectual exercise than anything, brought about by the vast cost difference between a marine genset (c £5k) and a building site frame job (c £200).

I suspect its doable, but not ultimately worth the saving.

Plus, when you have a new, silent running, v expensive marine generator it'll seem v posh and lovely. Whereas a donk donk dong g'donk Lister single lung oil burning 1940's engine that's been in a cow shed running milking pumps for 40 years is going to feel a bit naff!

 

[Ifraser]

You also need to consider the exhaust - Even with an extractor fan running, the area will get covered in soot within a short period of time.
I used to reverse a diesel car into a garage and within a year it was filthy in there.

The one I saw had the exhaust rooted out of the hull... didn't see how he had done it though. I think it was a pretty good option..particularly for those that may only want a genny on the odd occasion such as the SWMBO's super power hair dryer!!

 

[Wiggo]

You would presumably want to water inject it and run it through a Vetus type silencer, or it really would be a bit raucous at anchor. Alternatively, I guess an Eberspächer type skin fitting would allow you to not melt the hull...