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 Post subject: Repowering
PostPosted: 05 Jul 2007 15:15 
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Able Bodied Seaman

Joined: 24 Oct 2006 12:51
Posts: 48
We have 3500+ hours on our 1982 T37 which has a 33hp Westerbeke. My mechanic has said in the past that the 33 is a good candidate for an overhaul. Does anyone have experience in this regard?

Who has repowered their T37s? What replacement engine have you used? Ideas/advice?

Our engine uses a little oil; but, so far has been 100% reliable. My mechanic seems to think there is a lot of life left in this engine. Thoughts about the longevity of these engines?


 
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 Post subject: Re: Repowering
PostPosted: 06 Jul 2007 08:48 
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Midshipman

Joined: 22 Oct 2006 19:25
Posts: 61
I recommend the Westerbeke 44B four as a replacement. I have a Westerbeke 44A four (the Bs predecessor), which was a drop in replacement for the original Westerbeke. Others also recomend the Yanmar 3JH4E (3 cylinder 40 hp) or the 4JH4E (4 cylinder 55 hp). Jay


 
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 Post subject: Re: Repowering
PostPosted: 06 Aug 2007 15:01 
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Rail Meat

Joined: 04 Jan 2007 13:34
Posts: 7
I too replaced my 1981 Westerbeke. The parts to overhaul the old Westerbeke 50 were only a few thousand less than buying a new one. I bought a Westerbeke 44B. The key to this is that the price of the intallation can be 4 grand. The good part is you get a new exhaust system, new alternator new engine mounts, etc. By the way you need a 15 degree downward facing transmission to get the 44B to match up with the prop shaft. You'll get your money back when you sell the boat. and in the mean time have peace of mind.

Bill on Skylark


 
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 Post subject: Re: Repowering
PostPosted: 25 Aug 2007 12:26 
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Able Bodied Seaman

Joined: 24 Oct 2006 12:51
Posts: 48
Jay and Bill,

Thanks for the feedback on the repowering issue. I spoke again with the mechanic that has serviced my engine for years. He mentioned the same engines as possible replacements. He seemed to like the 55hp Yanmar. He had put one in a 38' Morgan; but, has not installed one in a T-37 and did not know off the top of his head if it would fit. Do you know if one has been, in fact, installed in a T-37? Regarding the Westerbeake 44hp, what cruising speed do you get with this engine. On the Chesapeake, I power more than I would like to admit and with our Westerbeake 33, 5-5 1/2 kts is about it.

As an aside, my mechanic thinks I should not be burning oil at this point. Said rings were prone to stick on this engine and recommended I put a quart of Marvel Mystery Oil in, run the engine for an hour and change oil and see if that helps the oil consumption. So, I'll be trying this home remedy first; but, if I could improve my cruising speed and have the comfort of having a new, reliable engine, may go ahead with the repower at some point.

Thanks again for the info.

Ted


 
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 Post subject: Re: Repowering
PostPosted: 25 Aug 2007 15:24 
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Rail Meat

Joined: 04 Jan 2007 13:34
Posts: 7
My new westerbeke engine, 44 hp,will move the boat at hull speed if the wind and seas are not severe. It starts up like a gas car engine and has been faultless.l
I wonder about installing a 55 hp engine. Will it weigh more than your present engine. What about fuel consumption. The 55 sounds like more engine than you can use. Bill


 
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 Post subject: Re: Repowering
PostPosted: 26 Aug 2007 21:00 
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Able Bodied Seaman

Joined: 31 Oct 2006 19:43
Posts: 37
I looked around on line for a while and found this quote. It is not mine but I believe the content is accurate.
"This is a general comment on fuel burn for diesel engines. Of the hundreds, if not thousands, of fuel consumption charts I have read all get 20hp/gal/hr within 10% or so. To simply relate this, if the engine is burning a quart of fuel an hour it is 'making 5hp'."
I think we can agree that our boats consume about 0.75 gallons per hour at 2000-2200 rpm and in my instance hull #52, W40 2:1 reduction and a 16.5" x11" right hand Gori 2 blade folding prop, I expect 5.9 to 6.2 with a clean bottom. By the consumption chart in the quote, my W40 is only burning fuel for 15 horsepower. If a Tartan 37 sistership has a 33 hp or a 55 hp engine I think it really is only going to need to make 15 hp to go 6 kts. I have a close friend with a Sabere 38 MK1 that is bigger than a T37 he has a W33 and it moves along just as nice as can be, he claims 0.65 gph at 1800rpm and 5.8kt. I know of a T37 that repowered with a 55 hp Yanmar he had to enlarge the exhuast to 3" plus a lot of other modifications, he had a 16" 3 blade MaxProp but the Yanmar had a 2.3? reduction so he had to run several hundered rpm higher speed since standard practice would be to run a 18" prop with a 55 hp engine, since there is no room to swing an 18" prop on a T37 he stayed with 16" and the standard (for that engine) low gear ratio with more rpms. I know a a couple of boats in the 35' range C&C 35 and a Freedom 35 these boats have Yanmar 27hp 3 cyl engines they are smooth quiet installations and move the boats along very well.
I have heard conversations on this site and others that the consensus of engine techs is to run the diesel at about 75% power for best operation overall. What I hear from those who use that advise is that the try to run the engines at 75% of the max rpm, so if an engine has a rating at 3000 rpm max that would be 2250 rpm but if the engine is only burning .075 gph making 15hp out of a potential 40hp then it is only loaded to 37%. Adding a new engine with 55 hp would make the utilization factor even less, repowering with a smaller engine is more in line with the actual amount of power used.

Sam


 
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 Post subject: Re: Repowering
PostPosted: 03 Dec 2007 12:15 
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Able Bodied Seaman

Joined: 24 Oct 2006 12:51
Posts: 48
Thanks for all the good information. Here's an update on where I am.

I got a second mechanic out to check my engine a couple of weeks ago. He did an interesting test when compression checking. Three cylinders test like a "new engine" and one cylinder produced only about 300psi. So, he shot oil in the weak cylinder and tested again which did not improve compression. His conclusion is that the problem is in the head, i.e. bad guides or bad valve(s) or both-not with the rings, etc.

Since I have replaced the heat exchanger, exhaust elbow, etc. etc. in recent years, am going to try the top end overhaul. If a visual inspection of cylinder walls reveals a problem when the head is off, will consider a complete overhaul or repower. Plus, I plan to rebuild the altenator, starter and replace the fresh water pump as problem avoidence while we are at it.

Based on the good feedback in this post and my positive experience with this engine, I'm considering the overhaul. However, if the repower route seems the way to go as "plan B", the Westerbeke 44B looks like a good choice since Yanmar would require changing to a 3" exhaust system.

If anyone has had experience in going this route, would appreciate hearing about it. Will post on how this all comes out.


 
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 Post subject: Re: Repowering
PostPosted: 20 Apr 2008 12:06 
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Able Bodied Seaman

Joined: 24 Oct 2006 12:51
Posts: 48
Here's the rest of the story........
My mechanic removed the head and inspected the cylinder walls and recommended only rebuilding the head. While he was at it, had him replace the original fresh water pump, send the injectors out for service, and send the starter and altenator out for overhaul. The boat is back in the water now and based on the first 1/2 hour of use, looks like everything is good-no smoking, much smoother. Think she may have a lot more life in her.

Incidently, this mechanic is very much against the idea of engine flushing. Thinks it creates more harm than good.

My observation in this process is there are a lot more "engine sellers" than mechanics out there and was happy to find a good mechanic who did what he said he would do and was accurate on his cost estimating.


 
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 Post subject: Re: Repowering
PostPosted: 20 Apr 2008 13:23 
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Midshipman

Joined: 05 Feb 2007 22:32
Posts: 74
Location: Cheaspeake Bay - Herrington Harbour South
Ted,

What part of the Chesapeake are you located, and what mechanic did you use?

Cheers,
Glenn

_________________
SOLARE #442


 
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 Post subject: Re: Repowering
PostPosted: 21 Apr 2008 07:53 
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Able Bodied Seaman

Joined: 24 Oct 2006 12:51
Posts: 48
We home port on the Magothy. Vosbury Marine did the work. They are located just across the Severn from the Naval Academy. I didn't have prior experience with them; acted on an recommendation from a neighbor. Was well pleased with the result.

Ted


 
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