Dream on! may be you could sell it to the gas grid?

I doubt that there would be much there but you could try using it for cooking? how did it form? could it leak into the house? you sure it is not argon or water gas?

cap the bore hole and insert a pipe with a pressure regulator and you are away -- likely will need to gas safed.

There are a small number of houses fed 'mains' gas f.o.c. from the methane that comes from a landfill site in Cheshire.
I don't know the composition, but the house that I saw runs a standard looking WB boiler.

Go for it!

Well motorbike engines are normally air or oil cooled so no good.

I would suggest looking at a small car engine, like a little 1ltr 3cyl vauxhall engine turning a large generator. It should be nice and quiet and ecomonical and have about 50 - 60 hp so should be able to give a very large output if needed.

Any smaller and I would suggest that it would not be able to provide enough heat to heating the water.

Timber

Reliant Robin? 750cc 32bhp http://www.3wheelers.com/bnplastics/history.html. Very light, all-aluminium, old favourite of racers, still plenty about.
Or there must be many small stationary or dumper truck single cyl water cooled single speed engines, Petter or similar. Surely, any boat engine? Water-cooled outboard motor?

Brilliant

Old outboard, sometimes it is easy to think too far out of the box. Thanks.

Thanks, some great ideas there and you've elevated my enthusiasm for the project. I've been mulling this one over for months. I'm aiming for highly insulated house so hope the heating demand is very low. I've been watching micro CHP for the past few years and every time one is promoted it disappears after a while - Disenco for example - or the launch dates get rolled back. I was a whiz with engines in days of Triumphs and BSAs - you just had to be. Now, a nice quiet understressed water cooled engine, and old Goldwing perhaps. Or, anyone got a steam engine? There used to a chap called Mallinson who made little marine steam engines, met him in the 80s. You see what you've done - I'm getting obsessed.

Mike

Yes I know, that was really why I am after a small engine that produces maximum torque at 3000 RMP (and hence max efficiency), and about 10kW and is watercooled and petrol/methane. Power can then be controlled with the fuel/air mixture and throttling to suit the load. One problem of using a car engine is that there is a need to secondary cool with air around the block/exhaust. As I have a couple of free hours today I shall go to the boat yard and see about small outboards and try and work out how easily they can be modified. I did think about the engine in my Suzuki car, it is about 50 BHP but at high revs, so would be noisy and as it is a 3 cylinder unit it vibrates a fair bit, okay when cruising but a bit too rough when only heat and power is needed.
I also wondered about using a heat exchanger from the exhaust, but then remembered my old VW Beetle and what happened when they went faulty, so avoiding that but does give one an opportunity to distil from seawater.

Tom
In a way you are right, but there is a limit to what can be easily done on an engine, hence the reason for a small engine rather than a large one running below par.

Posted By: fostertomReliant Robin? 750cc 32bhphttp://www.3wheelers.com/bnplastics/history.html." >http://www.3wheelers.com/bnplastics/history.html.Very light, all-aluminium, old favourite of racers, still plenty about.
Or there must be many small stationary or dumper truck single cyl water cooled single speed engines, Petter or similar. Surely, any boat engine? Water-cooled outboard motor?

Hmm.
Speaking as an ex-reliant owner, who has rebuilt the engines more than once, I strongly don't recommend it (or any car engine of that vintage) as a marine engine. A great engine in its day (that day being some time in the 1960s) it is really not the right thing for the job. It has no emissions controls so will produce awful fumes for you and fellow canal users. Having points and a carburettor it can't be relied upon to start on the button, not what you want half way through a lock.
And most importantly for a marine engine, they need a complete rebuild every 60,000 miles or so, which isn't very many hours.

Compare that to a modern small car engine - for example the 1.2 ecotec unit in my partner's Corsa (on LPG) has done 150,000 miles with only oil and filter changes, and still has very low emissions and no oil usage.

I wouldn't recommend motorbike engines for many of the same reasons. Small outboard motors may suffer from the same problems - they are optimised for high performance in a small package rather than longevity, and tend to be noisy, high revving and polluting.

Old or primitive new stationary diesels are also pretty horrible, smoke and noise wise.

-------------------
So what's the answer!?

Personally I would do the following: fit a simple electric drive to the boat (10kw is trivial) and a few cheap lead acid batteries. Install some solar panels on top of the boat, with a solar regulator. For low speed and short distances, use the battery. The battery also runs an inverter for your house loads.

For longer distances fire up a small, modern, refined genset (plenty of choice here, including water cooled) to maintain charge and provide some heating. I would perhaps choose a a "silent" water cooled 4kW Honda RV generator, running on propane.

For times when you need heat but not propulsion, fit a fuel powered heater (petrol, propane or diesel), do not waste the engine life by running it just for heat (it will be less economical to do that than use a boiler anyway).

Consider Propane in orange cylinders for the energy source. Both the gen-set and the cooking and heating can use this, and it may be safer, cheaper, cleaner and less trouble than petrol.

Ah, I assumed you were needing shaft power as well, but we are on the same page. What sort of electric drive are you considering, out of interest?

And are you sure you even need 10kW continuous? I have a feeling it might only take 2 or 3kW for continuous propulsion at such a low speed (thus the generator can be small), though of course you should size the electric drive to cope with the peak power needed for maneuvering.

Anyway, a quiet genset that is water cooled: for gas/petrol look at a Honda or Onan "RV generator". Or, the smaller Kubota diesel models.

A modern car petrol engine wouldn't be a bad choice, but will be heavier and trickier to install and connect to a suitable generator (please don't be tempted to use automotive alternators!). I also feel it will be quite a bit less fuel efficient which might be a factor if you drive it in the summer much.


Important factor: will the boat normally be driving when it's occupied or is it mainly stationary, like a house boat?

Posted By: fostertomThe Reliant design evolved into a 'modern' (by 60s/70s standard) 3-bearing aluminium ohv, from the original 2-bearing iron sv Austin 7 of 1923.

Indeed, and it gave very good power to weight ratio and economy for the time. Widely used in portable fire pumps as well, which could be easily carried by two men.

However, completely inappropriate as a power source these days, it just isn't clean enough (and this is the green building forum, right?!)

If you were a determined enthusiast you could get away with it if you added LPG with closed loop control, a catalyser, electronic points and so on, but by the time you've done all that you may as well have used a more modern engine in the first place, which has the added advantage of also being reliable :)

Ah, the difference between marketing and facts... %-P

Rgds

Damon