Hello again all,

I have a question that I'm hoping someone can answer for me.

I needed a new water pump for my boat, it has an OMC 3.8L V6 (GM 229
3.8L V6)so I did some pricing and a new (BOAT)water pump was around
60.00-160.00 depending on were you bought it. So I went to my local
Autoparts store and brought the old water pump with me and after some
searching found one that looked the exact same, bolt holes,
inlets/outlet, everything the same... It was actually for an 1970 307
Gm motor, got it for 25.00 new... What I'm now wondering is will it
mater if it (waterpump) was designed for a boat or car, are there any
differences, is the rotation differnt???? Just want to make sure before
installing it and running the motor.. Thanks for any info you guys can
give me....

Radman............

The water pump may or may be "ok" for your engine as parts such as the
circulating water pump can sometimes be interchanged for the marine item
depending on your set up.
Someone has already mentioned some important points about impeller and shaft
material which are very important and even more so for raw water cooled
boats in salt water, stamped sheet metal impeller vs cast bronze? Another
area often overlooked in making marine vs auto swaps is duty cycle. Car
runs at , what 1800 -2500 rpm cruising while the engine converted for marine
can be expected to cruise at 3000-3500 rpm or more. Your boat's engine is
loaded down like a car would be going up a hill while pulling a trailer.
A lot this suspenders and belt stuff can be scaled back to just belt if you
don't spend that much time on the water and you and your crew won't be but
at risk if you have a failure. I


--
Ron White
Boat building web address is
www.concentric.net/~knotreel

On 13 Jan 2005 18:47:05 -0800, "Radman" wrote:

Hello again all,

I have a question that I'm hoping someone can answer for me.

I needed a new water pump for my boat, it has an OMC 3.8L V6 (GM 229
3.8L V6)so I did some pricing and a new (BOAT)water pump was around
60.00-160.00 depending on were you bought it. So I went to my local
Autoparts store and brought the old water pump with me and after some
searching found one that looked the exact same, bolt holes,
inlets/outlet, everything the same... It was actually for an 1970 307
Gm motor, got it for 25.00 new... What I'm now wondering is will it
mater if it (waterpump) was designed for a boat or car, are there any
differences, is the rotation differnt???? Just want to make sure before
installing it and running the motor.. Thanks for any info you guys can
give me....

Radman............

You would like to think a marine water pump might have a bronze rotor
and perhaps a stainless or bronze shaft.
I suppose that an auto style pump would have a cast iron/steel
impeller and a steel shaft. It would be interesting to see what a
marine pump is actually made of!

Brian W

Thanks guys for your replys back...The boat will only be run in fresh
water and will probably only see a few trips a year.. I will probably
run it for a while just to see how long it will last...and keep a spare
for backup....

Thanks again...Radman...