seawater cooled diesel, good idea?

Rozinante · Post by **Rozinante** » Sat Feb 21, 2009 11:03 am

We are looking for a small 8-10 HP diesel for our 28 Herrshoff Rozinante. The smallest Yanmar is seawater cooled. This is the best size and an easier installation, but how sensible is sewater cooling. If I buy a new engine, how long will it last in NE coastal waters????

David · Post by **David** » Sat Feb 21, 2009 11:36 am

Yanmars are extremely good engines. Raw water cooled engines will generally not last as long as fresh water cooled engines, but for your boat and the short sailing seasons you have in New England it would most likely be fine for you. Just remember to keep the anodes changed. If you start with a new Yanmar, I would think it would last as long as you wish to keep it.

One thing to keep in mind. Beware of the Yanmar engine mounts. They are extremely soft and flexible; however, they must be changed relatively often--I don't remember the number of hours Yanmar specifies but they are not a permanent solution by any means--becuase they are so flexible and soft they wear out. The flexability of the mounts also means that the engine is allowed to move on the mounts a lot more than with stiffer mounts which adds movement to the prop shaft and will wear out the components of your stern gland as well. Stiffer mounts are the way to go, even though they transmit more vibration to the boat.

David

Rachel · Post by **Rachel** » Sat Feb 21, 2009 4:12 pm

This is meant to neither encourage nor dissuade you, but I believe this is the last year for manufacture of the 1GM10 (assuming that's what you're looking at).

(Yanmar keeps a good parts network, so I don't predict any imminent shortage.)

George ( C&C 40 ) · Post by **George ( C&C 40 )** » Sat Feb 21, 2009 6:53 pm

Hi Rozinante,

I've really enjoyed owning my 1979 Yanmar 3QM30(H). I've never had any problem getting parts, and the engine sounds as good today as the day it was made.

I wouldn't worry too much about seawater cooling. They make good engine cleaning products these days to keep the passages clean -- I use "Salt Away" on my engines. Keep an eye on the zincs!

One note of interest. Back in the day, Yanmar's cast iron block seawater cooled engines had lined cooling passages ( some sort of epoxy I think ) within the engine block. Lots of people would get the seawater cooled -- the (H) notation -- engine and then add freshwater cooling. This produced an engine that would last for decades. Not sure if that applies to the engines they make today or not.

Good luck,

George Jones

C&C 40 "Delphinus"
WL 24 "Poco Loco"

barrybrown · Post by **barrybrown** » Sat Feb 21, 2009 8:24 pm

Vetus sells a seawater strainer with a large screw-on plastic top, if you mount it somewhere with easy access like a cockpit locker at the end of the day you can close the seacock and flush the engine with fresh water through the open strainer. Not a perfect solution but maybe some peace of mind.

Barry

LazyGuy · Post by **LazyGuy** » Sat Feb 21, 2009 9:31 pm

Are you 100% sold on Yanmar? If you want fresh water cooled you can go with Beta 10. It is a Kubota diesel so the nearest tractor dealer will have your spare parts (Versus a marine $upplier)

http://www.betamarinenc.com/beta10.htm

There is also the Phasor which is also a Kubota block but the smallest they make is a 13 Hp.

http://www.phasormarine.com/p2-13-sm.htm

The buzz among the mechanics here is that Yanmar is looking to get out of the small marine engine market and stick with the big boys where there is a lot more money. As a result, the quality in the small diesels just isn't there anymore. My mechanic will no longer install small Yanmars in sailboats. He says that once they shifted to the YM model, there is too much rework involved.

JMHO

Post by **Tim** » Sun Feb 22, 2009 7:43 am

Something interesting to note is that the Beta 10 and the Beta 14 (BZ482) are the same engine, only with WOT RPM levels that are governed differently between the models. Otherwise, they are identical, including in price.

From my experience, Betas are nice engines. The Yanmar 1GM10 is an old workhorse and very reliable, but is sort of a dinosaur now--old technology, single cylinder, raw-water cooled. You would be well served to at least look seriously at your alternatives to be sure you don't miss out on something better.

Note that all engines will have their quirks when it comes to installing them in an old boat, and you should always be prepared for a pretty major rework of the engine room and foundation system, so don't let basic dimensional info alone drive your consideration process.

forrest · Post by **forrest** » Sun Feb 22, 2009 5:15 pm

Just a note on those Vetus strainers... I hate them, if the seal is not lubricated well they will seize shut in a nasty way and since they are all plastic you can't really use a tool on them. I've had to replace a few of them on various boats.

barrybrown · Post by **barrybrown** » Sun Feb 22, 2009 9:32 pm

I used one of the Vetus strainers for years, never lubricated the seal and never had it seize, also never wanted to use any tool on it for any reason.
Besides being a good strainer with good visibility it allows you to easily flush the engine and to run the engine while on the hard this makes winterizing and spring checkout much easier.
Different experience! I highly recommend them.

Barry

Rozinante · Post by **Rozinante** » Mon Feb 23, 2009 12:35 am

Anyone have experience with a Farymann A32? I hear they are loud, but something draws me to this engine.

Rozinante · Post by **Rozinante** » Mon Feb 23, 2009 12:36 am

They also offer the Farymann 18. On the 32, I can't remember if that is an A32 or a 32W?

Post by **Tim** » Mon Feb 23, 2009 7:20 am

Rozinante wrote:...something draws me to this engine.

It's the noise and vibration. ;<)

dmairspotter · Post by **dmairspotter** » Mon Feb 23, 2009 11:34 am

My 30 year old seawater cooled volvo still runs.

Hopefully not for long.

texaspsdx · Post by **texaspsdx** » Mon Feb 23, 2009 4:05 pm

My only complaint on the small Yanmar is the single cyclindar. Mine shook everything in the boat loose. Swapped mine out for a YSM12 and was much happier.

Richincident · Post by **Richincident** » Mon Feb 23, 2009 8:19 pm

My forty year old Volvo is raw water cooled and starts immediately and runs perfectly. I don't think raw water necessarily means a short life!

forrest · Post by **forrest** » Tue Feb 24, 2009 2:24 am

My experience with those strainers could certainly be due to the fact that it was charter guests cranking on those suckers.
Grossly generalizing, charterers tend to ruin anything they possibly can, no matter how stoutly built it is.