inboarder from a carengine

[oziwizzard]

g,day

is there may anyone out there who may can tell me ,where to find information about to change a carengine to a marine engine (inboard) i am starting to build from r, wood the romany 34 ft cat and try to safe some buck,s . there must somewhere this kind of information on the web but i am unable to find it . any information would be helpful

thx
rob

 

[Peterduck]

There are a number of considerations to look at here. If you are building a catamaran, surely you'll need two small engines rather than one larger one? Don't think about a petrol engine; it's just not worth it from a safety aspect, and the number of small diesel cars in Australia is miniscule. You'll need a total of about 4bhp per ton of displacement, so if you have a four ton boat then you only need 16 bhp. Stationary engines [eg pump and generator engines] are a better proposition. Conversion to marine specification involves a water-cooled exhaust manifold and heat exchanger, an adaptor to fit a marine gearbox [forward and reverse epicyclic, with a 2 or 3 to 1 reduction] and a satisfactory way of pumping the oil out of the sump. Sucking it out through the dipstick hole, although common, is not satisfactory. There is a company in Sydney called Diecon who convert slightly used small stationary diesels into marine diesels and sell them for a quite reasonable price.
Peter.

 

[Forbsie]

If you pm me your address, I'll send you a copy of a magazine article explaining the marinisation of a Ford 1.6 diesel.

 

[oziwizzard]

sorry there is a misunderstanding i am not living anymore at sydney 15 month ago i been moving back to germany.
it was not a problem if i still living at sydney but it is a problem cuz i am staying now at germany and here is it much harder to find this kind of infos.
thats my problem
rob

 

[Tisme]

this might help.

 

[cliffordpope]

Car engines often use Aluminium alloy, which is attacked by salt water. So you can't use direct sea-water cooling. You would need a heat exchanger, and another separate water pump to circulate the seawater.
People have used an ordinary car gearbox, but the ratios may well be wrong, and you have to either have a separate clutch lever or else rely on the syncromesh. It is a pretty primitive set-up.
Also car engines are not designed to resist much end-thrust, so unless the boat is very small you would need a separate thrust bearing.

 

[chippie]

See if you can find a Kubota industrial engine, they are the base engine for many small marine engines, so marine accessories are available.

 

[Agrothic]

An old but excellent publication on the subject is "Marine Convertions" by Nigel Warren, pub Adlard Coles Ltd. You may find it on a public library circuit! ISBN 0-229-11770-8
Cheers
Roger

 

[Boatmik]

Single inboards can be used on catamarans.

Such an installation would make a petrol engine less risky - but still I would agree with most of the posts above that a diesel is by far the most preferable solution. Rugged, reliable, good power through the rev range, not quite so dependent on electrics.

I have heard of and seen photos of inboard installations where the engine is mounted at the front end of the bridgedeck and the prop shaft runs exposed under the bridgedeck. It is held above the water when not needed, but dropped into the water when required.

How they get cooling water up to it and all the practical details - I just don't know.

If you can find info about such set ups - and if they seem to be reliable and workable for those using them - maybe that's a choice.

If the engine was in a seperate compartment that was vented to the under bridgedeck area that would remove the explosion factor. Fuel tanks would need to be similarly situated.

Probably worth checking with the designer about centre of gravity repercussions too. The smaller the boat, the bigger the repercussions.

Best Regards
Michael Storer