Shannon 36 repower

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.

Dougcole

Guru
Joined
Jan 21, 2008
Messages
2,167
Location
USA
Vessel Name
Morgan
Vessel Make
'05 Mainship 40T
Saw an interesting boat on Yachtwrold, a Shannon 36 Voyager. Only downside is that it has a pair of pretty high hour (2,000) DD 8.2L in it. I've heard a lot of bad things about this engine.

I'm sort of interested in the boat, it is well withing our price range, but not with those engines.

If you guys were going to repower it, what would you put in it? Any rough idea of cost?

Current motors are 250 hp each. I wouldn't want to go any smaller.

Thanks!
 
I'm assuming this is the 1991 Shannon in CT. She has less than 2000 hours on Detroit Diesels. That's roughly 100 hours for each of her 20 years. They're not even broken in yet at 2000 hours!!! And if they're not broken why start worrying about replacing engines? Personally I think Detroit Diesels are very durable and high quality engines. The boat looks great on YachtWorld and the price is good. Buy it and run it, as is, until you absolutely have to replace the engines (like in another 30 years or so).

Just my two cents.
 
Never heard of Shannon before but looks like a pretty nice downeast style cruiser. There are so many variables in re-powering, 40 to 80k would be the range I'd expect unless you do a lot yourself.
I agree with Steppen, only 2k hours and need replacing???
 
Shannon is best known for pretty high-quality blue water sail boats.

http://shannonyachts.com/


A former neighbor had a Shannon 50 foot sailboat, outfitted for a circumnavigation, then changed plans to make the voyage in a catamaran.

The pics make this look like a great boat. Cannot comment on the reliability of the engines, but 250hp turbos are sure going to be more fuel/maintenance than lesser options.
 
We are just tire kicking at this point until we get our old boat sold, which is going well, I have more interest than I expected.

But this boat meets a lot of our desires: Cruise speed between 16 and 20 knots, "downeast" sedan styling, 2 staterooms, one with a queen island, one with split bunks, flybridge, under 3'6" draft, twin engines, good to better quality.

Problem is, I really want a boat with newer engines, I already have a boat with really reliable N/A engines, I've loved them, except that I am sick of the never ending fluid leaks. My overwhelming desire is a clean, fresh engine room with good, easily traced wiring harnesses and clean odor free bildges.

I love Shannon's quality, they build a great boat, or at least a great sailboat. DD's have a rep, maybe undeserved, as being among the dirtiest of engines. (or is that just the 2 strokes?) It would be well within my budget to have them pulled (maybe sell them) and then clean every nook and cranny of the engine room, repaint, repower and rewire.

I scanned boat diesel for comments on the 8.2L. Overwhelmingly negative.

Just a thought.
 
Consider how easy it is to work on the engines. How easy will it be to get them out to replace them. In my search for a boat the 8.2 model was a big negative for any boat in which they were installed. I too, like you, read a lot of negative about them.
 
Repower

Pretty hard to beat the Cummin 6bta, especially at arpund 300 hp.

There is also the Yanmar, at good engine with lots of them available.

I am with you. A clean fresh smelling engine room goes a long way in making the boating experience fun.
 
Shannon

There is a Shannon 36 in the harbor here at Valdez,AK.
It is Cummins powered. The owners had it trucked from the east coast.

Nice boat.
 
The 8.2 "Fuel Pincher" was Detroit's attempt to enter the four-stroke market. The early engines had problems due to under-sized head bolts and an "open deck" which led to head gasket failures. The later models are supposedly better.
 
I owned a boat with 8.2's in the late 80's to early 90's,4 years total. As Ancora said, the original head bolts were changed from 13 mm to 14mm. These engines were popular in buses but they couldn't hold up to the up and down slow and fast service. They had a reputation of "blowing up".
In the constant speed , constant load service of boats they proved to be a little bit better. My engines were early versions that were upgraded to the larger headbolts and newer head gaskets.
One of the problems with these engines was that there were very few people who were trained to service them. They took special tools for the injectors that most detroit mechanics didn't have and wouldn't buy because there wasn't enough of the engines to work on. Even our local Detroit dealer (Power Products in Wakefield Mass) only had one or two techs that would touch them.
They were PHENOMENAL on fuel consumption, using miniscule amounts of fuel. Buying parts for them was also a chore and I can imagine it is much worse today, since they have been out of production for years.
I would hesitate to buy a boat with this power unless the deal was so good,you could repower and come out ahead.
The 8.2's were popular in JC 31 and 35's, Roughwaters and several other production and semi custom boats. In my opinion you can do better.
 

Latest posts

Back
Top Bottom