eng. repower

[SV Romance]

I have just joined the mail list recently. I am thinking about an engine repower, replacing the W58. It looks to me that most the boats have repowered with a Yanmar 54 or larger. Did they all refit the Velvet Drive? If so, what adapter
plate was used? Or if not, what Yanmar transmission was used?

 

Thanks, Bill

s/v Romance

 

[RichCarter]

Bill,

I took careful notes when I repowered.  Please read this.

 

http://www.richardcarter.net/repower/

 

it’s probably best to have a stiff drink when you read the end of the last page.

 

Rich

 

[Chuck Ruble]

Bill, I repowered with the Cummins. Still working through my refit so I can’t offer long term results.
The beds in the boat should be scrapped. They are junk. Plan to build new. The Cummins has an odd foot print, the front and rear mount brackets were on different planes. If they were supposed to be on the same plane I must have missed something. I fab’d the new beds to accommodate this.
The Velvet drive bolted to the supplied adapter (I told Sheri what I was bolting to the bobtail engine).
The worst obstacle to overcome is Westerbeke dumped the exhaust off the front of the engine with a custom exhaust manifold for the v-drive arrangement. You have to reroute the exhaust around the engine. Getting a substantial drop between the output, injection elbow and lift muffler is a challenge. This is critical. If water can seep back to the exhaust port it can/will result in corossion or worse a hydro locked engine. I see this on boats that have been transported over the road as they can experience forces nobody really gave much consideration for.

I like the new common rail Yanmars. They are very quiet! Amazingly quiet. The Cummins is a noisy engine and not a pretty sounding one either. An old Ford Lehman or a 3208 is like a symphony to my ears, the Cummins does not aspire to make music only industrial power. I spent a lot of time creating a tight sound enclosure for the engine to learn the V-drive is a noisy piece of equipment also. Personal ear protection is simpler on long trips I’d think.

The Yanmar 54 would be ample power for our boats. The W60 and W58 were making 48-55 bhp at best. I look at the boat as a slow power boat. I liked the high torque rating on the Cummins and the low rpm value, 2800 at wot. I think the Yanmar is 3600.

Parts for the Komastsu block should be available forever and a day. Cummins built millions of these units. Marcus used the Bowman products also used on the Perkins 4-236 to marinize the engine. As long as he’s around you’ll be able to get those parts in the US as well.

The ZFcone gears supplied with the Yanmars are fine units up to the 54 hp model, the ZF and Kanzaki hydraulic gear are better applications for the 75 and up. Straight output is the current config. You could use a gear with a few degrees of down angle and set the engine closer to level, raising the height of the exhaust output. Not sure if this would impact the limitations of the existing enclosure though.

You’ll need to increase your exhaust diameter. Exhaust hose is expensive.

Move the new engine panel to above the bridge deck. Currently If you fill the cockpit with water your controls are immersed until it drains.

Rule of thumb for pricing a repower, double the engine price. This will give you a safe number to have a shop do it.

If you plan to sell the boat in 5 or so years go with the Yanmar. It won’t frighten the uninformed when they look at it. If you plan to wear out an engine over the next 10-15 years take your pick.

Write a check at a boat show if you want the Yanmar. Best pricing available and they may waive freight.

Hope some of this helps.

[JodyandStephen]

We re-powered 6 months ago, after years of research, selected a Beta 50. Ordered with a factory supplied bell housing that our velvet drive simply bolted onto.  Also ordered the remote oil filter and shallow oil pan to ensure proper fit.  This fitted pretty well directly onto the mount positions, and was a very simple and inexpensive swap out.  Very, very happy with the result. Full hull speed, and the fuel savings are remarkable.

Good luck with your decision making.

 

Stephen Parry

S.V. Blue Pelican

 

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[Dumela]

Sorry for the late reply to Stephen…..we too repowered our Pearson 424 with a Beta 50. It is quiet, efficient and economical to run and was not too much hassle to fit. We rebuilt the RV-20 at the same time but it did not really need much. I have been running it without any coolant for about 10 years in all sorts of conditions; it never gets above 180 degrees.

Thom
SV Dumela

[Rob Osterman]

Hi Bill,

I repowered six months ago with a Yanmar 4JH80. I found Rich’s write-up to be tremendously valuable in planning and executing the project. The new generation Yanmar’s max out at 3,200RPM and I didn’t need to change any of the transmission gear ratios. I believe the Walter V-Drive gear parts are close to $1,000 which you might want to consider changing to the new RV-26 if you needed to re-gear.

The new Yanmar fits the Velvet Drive with an adapter plate. The internal damper plate is much more substantial than the previous Westerbeke/Velvet Drive combo. I would plan on rebuilding your Velvet Drive and replacing the fuel tank while you’re at it.

I re-pitched to a 20×12 (from the original 20×13.) I’m able to hit full RPM and max out around 8.3kts.

If you’re doing it yourself — building a mockup of the engine with all the correct dimensions really helps when you start second guessing yourself if it will all fit. Be sure to plan the alignment between the engine and the Walter V-Drive. There’s a small alignment tool that fits on a key-ring to ensure the input shaft is aligned to your engine. This is one of the details I should have paid more attention to and would have saved me some trouble had I planned for it.

[Ben Frothingham]

Chuck mentions that the V-drive is a noisy piece of equipment. I just bought hull 81 in September, now named Papaya, and I have limited sailing time. I agree, the V-drive is noisy when free-wheeling. The question is, what does it sound like new? Is it noisy when new? or is mine just worn and I'm hearing bearing noise that should not be there?

Thoughts?

[RichCarter]

As I recall, the RV-20 was a bit noisy.  The RV-26 I have now is not as noisy.  I took great care to align the thing when I repowered so perhaps that’s why it seems quieter.  There are differences in the two models so maybe the larger V-drive just runs quieter.

 

Rich

 

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