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Boat Engines
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 |
Boat Engines
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 |
Boat Engines
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 |
Boat Engines
Steve Morrisby wrote: 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. OT: it would be easier imo to get a used marine engine, tear it down, and rebuild it ... than to buy all those marine parts (wet exhaust parts etc etc) you'd have to get to bolt onto that truck engine. |
Boat Engines
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 |
Boat Engines
On Fri, 08 Dec 2006 20:25:06 GMT Steve Morrisby
) wrote: 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. That's possible, but remember above companies sell complete products, e.g. engine, cooling system, gearbox and control panel. 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. Used gearboxes are rare, bell housings even more, you'll pay full for them. I know what I'm talking about: the single coupling to replace the old worn coupling http://qatsi.ath.cx/cgi-bin/foto/438/76.jpg is half the price the used gen-set http://qatsi.ath.cx/cgi-bin/foto/401/06.jpg did cost. 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. Buying a complete second had engine would be the easiest option, doing it all yourself can be fun if you like it. -- Richard e-mail: vervang/replace invalid door/with NL.net http://web.inter.nl.net/users/schnecke/ |
Boat Engines
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 |
Boat Engines
Ah yes!. I did not consider that the marine engine is continuous duty. Considering that fact the cost is probably justified.
Referring to Max Camirands posting, I also wondered about air cooling. Deutz built a fine range of air cooled engines, and it would keep the boat nice and warm!. But I am still up against the continuous duty problem. Thanks for all your input. Steve "Richard van den Berg" wrote in message ... On Fri, 08 Dec 2006 20:25:06 GMT Steve Morrisby ) wrote: 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. That's possible, but remember above companies sell complete products, e.g. engine, cooling system, gearbox and control panel. 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. Used gearboxes are rare, bell housings even more, you'll pay full for them. I know what I'm talking about: the single coupling to replace the old worn coupling http://qatsi.ath.cx/cgi-bin/foto/438/76.jpg is half the price the used gen-set http://qatsi.ath.cx/cgi-bin/foto/401/06.jpg did cost. 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. Buying a complete second had engine would be the easiest option, doing it all yourself can be fun if you like it. -- Richard e-mail: vervang/replace invalid door/with NL.net http://web.inter.nl.net/users/schnecke/ |
Boat Engines
On Mon, 11 Dec 2006 11:05:13 GMT Steve Morrisby
) wrote: [-- text/plain, encoding quoted-printable, charset: iso-8859-1, 56 lines --] Ah yes!. I did not consider that the marine engine is continuous duty. Considering that fact the cost is probably justified. That's open for discussion.;-) Referring to Max Camirands posting, I also wondered about air cooling. Deutz built a fine range of air cooled engines, and it would keep the boat nice and warm!. If you like the engineroom smell, then it's allright, it's not my choice. Running airducts is a matter of space, gen-sets are somehow that way built. But I am still up against the continuous duty problem. I see that more as a sale/warranty figure. A displacing ship with more than 5 hp/ton has enough power, equipped with the right prop of course. -- Richard e-mail: vervang/replace invalid door/with NL.net |
Boat Engines
If air cooling didn't work out, you could remove the radiator and
instead pump the coolant through a coil of copper pipe running through a sea chest (small seawater-flooded compartment built inside on the inside surface of the hull). Kind of like a keel cooler, but inside. The advantage over cooling with raw seawater is that you don't get corrosion inside your engine, both from the seawater and from the galvanic action it creates between the dissimilar metals in the engine. Of course, it's slightly more complicated. I'm not sure that I understand the continuous duty problem. Certainly, truck engines aren't meant to run at 100% of rated RPM all the time. However, they can do long 'passages' at highway loads, which (I think) is around a third of rated HP. Truckers even leave their engines turning at high idle while they're stopped. Why wouldn't you use a 400hp truck engine as a 100hp boat engine? If yours is a big ol' boat running at displacement speeds, the difference in weight wouldn't matter much. Anyway, I got the impression that when manufacturers sold an engine as "continuous-rated" versus "intermittent-rated", half the difference was simply reducing the rated HP. I could easily be wrong. I've never done this sort of thing. I'm just thinking about how I'd do it if I were in a 'gypsy' frame of mind, and I wanted a decent boat for minimum cost. What do you experienced folk think? -Max Camirand Steve Morrisby wrote: Ah yes!. I did not consider that the marine engine is continuous duty. Considering that fact the cost is probably justified. Referring to Max Camirands posting, I also wondered about air cooling. Deutz built a fine range of air cooled engines, and it would keep the boat nice and warm!. But I am still up against the continuous duty problem. Thanks for all your input. Steve |
Boat Engines
I understood continuous duty to mean not only an ability of the engine to
run reliably for extended periods at full load but also that all the metalwork, fittings etc are of a superior standard. Hence the cost. I may be wrong here but I seem to recall that running engines off load or on reduced loads for extended periods is not good for them. Leads to glazed barrels or something like that???. Referring to air cooled, I rather like the smell of engine rooms but I can see on a boat you would have to build in a heat exchanger to isolate the cabin from the "raw" heated air, I just think that a heat exchanger for air is easier to build that one for a sea/fresh water combination. Also no holes in the hull. However on the down side, don't water cooled engines run quieter than air cooled. So many points to consider!. Having said all of the above however I believe that the engineering required is beyond me and by the time I gather the experience and tools to do the work too much time will have gone by!. I will just have to save a bit harder and buy a marine engine. Steve |
Boat Engines
I was going to suggest talk to Polar Engineering, but they have closed
and Bowman have taken on their product range. http://www.ejbowman.co.uk/news/News_polar.htm From my research when I was looking for a marine engine, the only difference between continuous and intermittent rating is the power allowed and duration. I bought a Daewoo L136 from Watermota UK - 160Hp at 2200 rpm continuous rating. Excellent engine, very reliable, frugal and well priced and this particular engine is used when re-engining trawlers whose Gardners are beyond economic rebuild or repair. Daewoo do a 70 Hp engine - http://www.watermota.co.uk/daewool034.html Give Mike Beacham a call - you might be surprised!! Colin Stone |
Boat Engines
max camirand wrote: If air cooling didn't work out, you could remove the radiator and instead pump the coolant through a coil of copper pipe running through a sea chest (small seawater-flooded compartment built inside on the inside surface of the hull). Kind of like a keel cooler, but inside. The advantage over cooling with raw seawater is that you don't get corrosion inside your engine, both from the seawater and from the galvanic action it creates between the dissimilar metals in the engine. Of course, it's slightly more complicated. Why bother with all that complication. Just go on E-Bay and search for "Heat Exchanger" and you will find a plethora of all sizes and shapes. Then add a raw water pump on a bracket, some plumbing and replace the radiator with the heat exchanger. |
Boat Engines
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 |
Boat Engines
Have a look at www.abato.nl,
a Dutch company that imports Chinese made Deutz 226B marine diesel engines. Weichai Deutz Engineering co, joint venture. Deutz moved the production line of the 226B diesels to China, a few years back. Quality control is still executed by German engineers, in the Weichai plant in China, so they say. Text on this website is in Dutch, but you can find some interesting links. 75 hp model costs 4300 euro, excl. VAT.(without gearbox). Pricing is more than OK, I think, but about reliability I haven't heard anything yet, it's too soon for that. If I ever need a diesel, I think I'll go for it. Beats a truck engine marinised by an amateur! Bye, Luk "Steve Morrisby" schreef in bericht ... 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 |
Boat Engines
On Wed, 13 Dec 2006 23:26:21 +0100 Heidi&Luc
) wrote: Have a look at www.abato.nl, a Dutch company that imports Chinese made Deutz 226B marine diesel engines. Weichai Deutz Engineering co, joint venture. Deutz moved the production line of the 226B diesels to China, a few years back. Quality control is still executed by German engineers, in the Weichai plant in China, so they say. Text on this website is in Dutch, but you can find some interesting links. 75 hp model costs 4300 euro, excl. VAT.(without gearbox). Pricing is more than OK, I think, but about reliability I haven't heard anything yet, it's too soon for that. If I ever need a diesel, I think I'll go for it. Beats a truck engine marinised by an amateur! There are english datasheets available. Before 1985 it was a MWM engine, Deutz bought MWM in 1985: http://www.deutz.nl/historie/1980-2000.htm and Fendt also used these engine types - D2xx range: http://www.fendt-freunde.de/datenbank/fs_dat1.htm Compare these pictures: http://www.abato.nl/motoren/images/w...z/_BHF0191.jpg and http://www/cgi-bin/foto/436/50.jpg I dont't have a picture from exact the same angle, more pictures at http://www/cgi-bin/cath_pub?5 -- Richard e-mail: vervang/replace invalid door/with NL.net |
Boat Engines
Thanks to everyone for those links to other suppliers and for your
comments. They were all well noted!. Yesterday I talked to my car mechanic about continuous duty engines. He said they did not really exist but likened it to aero engines which are required to run for long periods at a time without missing a beat. "Yes" he said "they are built to exacting specifications and components are replaced after a recorded period long before they fail." "What about old VW and Subaru engines which are used in home builds" I asked "They are usually rebuilt or modified by dedicated and highly competent amateurs and maintained to a very high standard" the mechanic replied. So. A continuous duty engine is one that is well built (ie almost any new engine) and maintained to a high standard (hey I do that to my car already). It's all in the maintenance!. Steve |
Boat Engines
"It's all in maintenance". We may differ slightly on that position. You
will find that an engine built for auto use has a much different camshaft than does one built for marine use. It is understandable if you visualize the difference in acceleration in each application. Automotive cams do not provide good marine performance. I have proven that several times with Chev 350's auto engines placed directly into marine applications (I/O). Don Dando "Steve Morrisby" wrote in message ... Thanks to everyone for those links to other suppliers and for your comments. They were all well noted!. Yesterday I talked to my car mechanic about continuous duty engines. He said they did not really exist but likened it to aero engines which are required to run for long periods at a time without missing a beat. "Yes" he said "they are built to exacting specifications and components are replaced after a recorded period long before they fail." "What about old VW and Subaru engines which are used in home builds" I asked "They are usually rebuilt or modified by dedicated and highly competent amateurs and maintained to a very high standard" the mechanic replied. So. A continuous duty engine is one that is well built (ie almost any new engine) and maintained to a high standard (hey I do that to my car already). It's all in the maintenance!. Steve |
Boat Engines
"Contiuous Duty" Sure they exist. Go check out John Deere's line of
marine diesels. They have them available in various duty ratings, including continuous. And you bet it's all in the maintenance... give them clean fuel and air, and keep the oil clean and they'll run damm near forever. |
Boat Engines
Ah aren't good news groups great!. I have learnt more on this subject over
the past weeks than I ever would have at a trade show or from a series of manufacturers sales brochures (and they are very good sources of information) I kinna guessed there was a little more to the subject of marine engines, but not how much. There is now no doubt in my mind that to do anything but buy one from a reputable source would be a big mistake. Again thanks for all your input Steve |
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