It can be done very successfully, but not by an amatuer. The duty cycle of
an automotive engine is around 30%. Marine engines require a 100% duty
cycle. Converting an automotive engine to marine involves far more than just
cooling system and exhaust. However there are firms that sell conversion
kits that do a reasonably good job without extensive engine mods, but be
careful. Under no circumstance will you ever be able to open up the trottle
and run the boat in that manner, because the engine will self destruct.
Steve

"Steve Morrisby" wrote in message
...
Hi there

I have been looking at the UK market for a 75HP marine inboard engine.
Those
that look good are products from Volvo, Betamarine and Lombardini, but
what
a price!. I struggle with the fact that my new car cost less than one of
these and that got me to thinking if I could do it myself.

What are the pitfalls in "marineising" a good used truck engine, are
aftermarket kits sold and what about marrying the gearbox to the engine
bell
housing.

I seem to recall reading a thread on this subject some years back, but at
the time I was not too interested. Now of course I cannot find threads
going
that far back.

TIA

Steve

It's been talked to death.

you will need a foreward and reverse thrust bearing, wrong gearing,
spark proof alternator, and a wet exhaust system.

If you can get 2 or 3 old 318's, run 'em till they burn out, and
rebuild the dead ones over the winter.

With any luck, thay won't last long enough to rust or electrolyze out.

Terry K

That makes me wonder if it would be possible to keep the engine
air-cooled and exhausted through a dry stack, perhaps by fitting a
bigger radiator and using forced-air cooling ducts.

To get around the gearbox problem, why not couple the engine to a
hydraulic pump and use a hydraulic motor with a thrust bearing to drive
the prop shaft? With a short run of hose, I don't know if the energy
lost would be great. You could use your main engine to power a bow
thruster that way, too.

Just a thought.

-Max Camirand


Terry K wrote:
It's been talked to death.

you will need a foreward and reverse thrust bearing, wrong gearing,
spark proof alternator, and a wet exhaust system.

If you can get 2 or 3 old 318's, run 'em till they burn out, and
rebuild the dead ones over the winter.

With any luck, thay won't last long enough to rust or electrolyze out.

Terry K

max camirand wrote:
snip

To get around the gearbox problem, why not couple the engine to a
hydraulic pump and use a hydraulic motor with a thrust bearing to drive
the prop shaft? With a short run of hose, I don't know if the energy
lost would be great. You could use your main engine to power a bow
thruster that way, too.

Just a thought.

-Max Camirand


Sounds like a good plan, but I think the cost will bite you. You will
need to engineer the pump, motor and prop combination. You might best
fund a college research program, or ask around the fishing docks.

Oh yeah, all that pumpery will be heavy.

Terry K

It's been talked to death.

you will need a foreward and reverse thrust bearing, wrong gearing, and
a wet exhaust system.

If you can get 2 or 3 old 318's, run 'em till they burn out, and
rebuild the dead ones over the winter.

With any luck, thay won't last long enough to rust or electrolyze out.

Terry k