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/

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/

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

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

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

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

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.

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

"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

"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.