marinising engines

pauls_SPT

Well-Known Member
Joined
13 May 2004
Messages
81
Location
Newquay/Falmouth
Visit site
...or should that be marinating...not sure, anyway, how practical is it to convert a car engine to go into a boat? The GMC lump in my boat went bang in no small way a couple of weeks ago and, assuming every internal part of it is broken, I'll be looking for a new engine.

The problem is, 3 litre GMC engines are nigh on impossible to find, so I'm looking around for alternatives and one fairly obvious swap would be for a Ford V6 (Essex or Cologne), as they knock out about the same power, are about the same size and weigh about the same, too...they're also relatively cheap (under 500.00, at any rate).

How would I start with converting it to life at sea, though? The old GMC unit is pretty standard except for the inlet/exhaust manifolds, but can I get those for other engines?

Any help/advice/cautionary tales will be much appreciated,

Thanks,

Paul
 
I marinised a 1600 XLD out of a Ford Escort van. I followed an article in PBO or Boat Mart which went through all the steps. Maybe worth talking to Lancing Marine. ASAP also sell the parts required.
 
Read Nigel Warren's 'Marine Conversions' if you can get it. My edition is 1982, so unlikely to be in print now, but local library ,may turn up something.

A complete run down on selecting, converting, marinising and everything else-ing of road vehicle engines for marine use, inlcuding stern gear, prop size tables, cooling systems, gearboxes, mounting and drive, etc etc.

Read it and at least you will know what you are letting yourself in for!
 
Those Ford V6s are now very old, and finding a good one would be difficult. marinising gear doesnt come cheap, so i would either replace like for like or consider a new engine such as a small diesel from lancing marine or similar.

The GMC 3 litre is a straight 4 block is it not? Companies like Coastal Rides still sell those brand new with volvo penta badges and red paint. They may even have second hand units for sale too.

Good luck whatever way you go about it.
 
Marinisers can get bogged down with trying to make all the bits fit on the engine, eg, the heat exchanger is made to fit on the thermostat housing. However, consider that any heat exchanger could be remotely mounted in the engine room, use a suitable spare thermostat housing bolted under it and run hoses to the engine. Same with oil coolers etc. The water cooled exhaust manifold and gearbox adaptor plate may be the only problems, but there are lots about, and they can be fabricated.
You should get insulated return alternator and starter, to avoid having the negative in the engine block. I think Lucas can modify starters, and alternators are off the shelf. ( A boat was fitted with an ex-lorry starter, not insulated return. The boat left Newlyn with all new anodes on, when it got to the I.O.M there were none.)
 
Marinese an engine that it is easy to get; the Mercedes 4,5 and 6 cylinder diesel engines are plentyfull and very durable. I strongly suggest that you contact Lancing Marine. Would you need a gearbox too?
 
In my old Simmonds ski boat it has a marinised ford consul engine. Principle components are water pump that takes in water this then runs through a copper pipe in the sump cooling the oil then on to a purpose made manifold where the water is injected to cool and silence the exhaust. The cooling circuit through the cylinder jackets etc is straight forward the radiator has been substituted for channels that run the length of the boat and back using the hull as a heat exchanger, my boat being aluminium makes this possible.
 
Thanks very much for all the help and info - I'll certainly have a chat with Lancing Marine, as everybody seems to rate them quite highly. I'm looking for something I can fit straight onto the existing sterndrive - hopefully I can use some of the bits off the broken engine (e.g. alternator, starter, flywheel) with a little modification.

Thanks again,

Paul
 
Top