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Crusing on one engine

Posted: Fri Sep 18, 2009 10:34 am
by jddens
Some of you may recall that I have a low oil pressure problem on my starboard motor. I have since had it checked by a mechanic and it needs to be rebuilt/replaced. The estimate is somewhere between $4,000-$6500. I don't want to spend that money at this time so I have developed a work around. I use both engines to maneuver then shut down the starboard and cruise on the port engine at about 2200rpm, trawler speed..............question....is there any down side to this other than putting extra hours on the port engine?

I have Hurth transmissions and leave the port in neutral when shut down..........Thanks......John

Posted: Fri Sep 18, 2009 10:47 am
by jwrape
If you have a low oil pressure problem I would say that motor is not gonna let you keep running it for much longer. If you want a simpler fix I would say replace the oil pump on that engine and get a little more life out of it.

Why do you think it needs rebuilding other than the oil pressure? Is it smoking, making noise or anything else.

Have you checked the oil pressure at the engine. My oil pressure gauges are not correct. One engine has more than the other....

If the motor still runs good and not smoking, knocking etc... I would replace the oil pump and keep on boatin'...

Just because a mechanic calls himself a mechanic doesn't mean he is always knowledgeable.


What all did he check to come to the decision that you need a rebuild?

Posted: Fri Sep 18, 2009 10:56 am
by jwrape
Ok, so I went back and read your old posts on this issue.
I would say as long as the motor runs good without smoking, knocking etc... you should just replace the oil pump with a new one. I would venture to say that you could possibly do it in the boat depending upon how much cleareance you have or could obtain under the oil pan.

If the oil pan is too close to the bottom of the boat to remove then take loose the mounts and jack the motor up just enough to remove it.

Now if the engine is down in a unaccessible place then, yea, the motor would have to be pulled. If the motor has to be pulled, you might as well rebuild while it's out.

Hope this helps.

Posted: Fri Sep 18, 2009 10:57 am
by jddens
Engine is defiantly sick.......I have build hotrod motors and just wanted a second opinion from the mechanic and an estimate. I have tried a mechanical gauge and done a compression check and had the oil analized so I know it needs fix'in. I'm guessing it will last a long time using as I am now, just for maneuvering.

I'm wondering if there is any down side to running on one engine with the other in neutral......

Posted: Fri Sep 18, 2009 10:59 am
by jwrape
jddens wrote:Engine is defiantly sick.......I have build hotrod motors and just wanted a second opinion from the mechanic and an estimate. I have tried a mechanical gauge and done a compression check and had the oil analized so I know it needs fix'in. I'm guessing it will last a long time using as I am now, just for maneuvering.

I'm wondering if there is any down side to running on one engine with the other in neutral......
Oh, so you've got skills. :D
In that case I would say that there is no ill affects that come to mind by dragging a nuetral prop or pulling with one motor over the other.
The only thing would be explaining to a new buyer why one engine has far more hours than the other on the meter.

Posted: Fri Sep 18, 2009 11:00 am
by jddens
no way to get to the oil pump with the motor in the boat, it would have to come out.........

Posted: Fri Sep 18, 2009 11:03 am
by jddens
Thanks jwrape......new owner??? no way, I love this boat, even going slow. I will eventually fix the motor, just don't want to spend the $$ right now...........

Posted: Fri Sep 18, 2009 11:07 am
by jwrape
jddens wrote:no way to get to the oil pump with the motor in the boat, it would have to come out.........
Oh, that sucks! Oh well, ride it the way you are... You gotta be on the water. Might as well use it... :D I would and have... I had a shaft come loose on me and ran around all day until I got back to the dock to fix it.

Posted: Fri Sep 18, 2009 11:11 am
by mpulsev10
what engine do you have ? I know Jerry's marine in south florida has a special on a crate 5.7 chevy long block for $2385, not sure on the pricing on the big blocks.

--charlie

Posted: Fri Sep 18, 2009 11:26 am
by jddens
They are Merc 350's. Throttle body injected with 330HP each.

Posted: Fri Sep 18, 2009 11:50 am
by ready123
What about reconditioned engines they are much cheaper, around $2K:
http://www.portcitymachine.com/marine.html

Posted: Fri Sep 18, 2009 12:57 pm
by jddens
engine cost is about half the estimate, rest is yard fee's and labor fees.......what do they say about a "hole in the water to throw money in"???

If I can find a place close to the yard to keep the boat, I'm tempted to have them put the motor in my truck and bring it home and do it myself. I've built hotrod motors but I'll not very familiar with marine motors and these are closed loop cooling so even more parts and pumps and stuff.......I'd hate to get it back in the boat only to find I screwed something up and have to start over.........

Posted: Fri Sep 18, 2009 1:00 pm
by jwrape
jddens wrote:engine cost is about half the estimate, rest is yard fee's and labor fees.......what do they say about a "hole in the water to throw money in"???

If I can find a place close to the yard to keep the boat, I'm tempted to have them put the motor in my truck and bring it home and do it myself. I've built hotrod motors but I'll not very familiar with marine motors and these are closed loop cooling so even more parts and pumps and stuff.......I'd hate to get it back in the boat only to find I screwed something up and have to start over.........
From what I understand i beleive if you found another block and stripped yours and just put it back together, all should work fine. It's mainly about the direction of the rotation as well as the marine block being balanced properly. the rest of it is just appendages on the block.

Posted: Sat Sep 19, 2009 6:35 am
by RWS
The prop on the tired engine is probably spinning at trawler speeds.

Make sure that this does not cause a failure in your transmission due to no oil circulation from the pump.

If it does, you will have to clamp that shaft to keep it from turning while running on one.

RWS

Re: Crusing on one engine

Posted: Sat Sep 19, 2009 11:02 am
by gjrylands
jddens wrote:Some of you may recall that I have a low oil pressure problem on my starboard motor. I have since had it checked by a mechanic and it needs to be rebuilt/replaced. The estimate is somewhere between $4,000-$6500. I don't want to spend that money at this time so I have developed a work around. I use both engines to maneuver then shut down the starboard and cruise on the port engine at about 2200rpm, trawler speed..............question....is there any down side to this other than putting extra hours on the port engine?

I have Hurth transmissions and leave the port in neutral when shut down..........Thanks......John

Clamping the shaft wouldn't be practical since he will be using the engine to maneuver when docking or in tight places.

One thing for sure, it would be embracing to have a sailboat pass you. All joking aside, running on one engine shouldn’t damage the transmission. At 2200rpm you will only be moving at about 7-8 mph. I wouldn’t think you would be planning any long trips, so limited runs should be OK.