Repowering 2

Hi Gary,
Lets rewind the repower story and begin a new.
Your boat is 14000 pounds or 7 tons, the design for auxillary is 3 hp/ton, this will get you along on calm days in relatively flat water. We have done many repowers over the years and have learned that a ratio of?3.5 hp/ton in most cases will get you hull speed.
The BCC a grand old boat, but she is heavy, not a UDBL design sled.
With that said, any horse power beyond what you need to reach hull speed is wasted along with the addition cost of a larger engine.?Most of the newer engine designs, in particular Westerbeke/Universal do not overload when you reach hull speed, they simply stop producing power, you can still push the throttle further forward, but you will gain nothing in return, gone is the black smoke telltail of yesteryears when you have overloaded the engine, it’s a process of new injection system technology.
We proved this point last fall with the 35D THREE, where the customer speified a 1:1 ratio transmission for his Islander, when we reached hull speed at 2100 rpms, you could watch the throttle lever and injection pump control lever move beyond 2100 rpms, but no additional power, rpms or smoke-designed to be a clean burning engine.
Imagine that, an engine that knows it limits.
Over the years we have found the best horsepower/weight ratio is 3.5 hp/ton, this should take you to hull speed, handle adverse wind, wave?and current conditions.
Your BCC is rated at 14,000 pounds or 7 tons, 7 x 3.5 hp =24.5 hp
I know this is a lot less horsepower than you think you realy need, but hull speed is hull speed and there is no getting around it.
I recommend you go with the Universal M25XPB, it’s a little shorter and narrower than the 35D Three, but it is a workhorse and there is a lot of them out there, they have been around for a long time, it’s one engine that is realy hard to kill, trust me, I have a lot of customers who tried (not by choice, you know, dumb stuff). Being a alot of them out there in boats means parts supplies will be around for a long time. In fact, it’s the hotest selliing engine in the Universal product line.
The M25XPB is rated at 26 hp at 3000 rpm, 600 less than the 35D, it’s lighter as well, less is better. Down load the drawings from, max engine spacing is 16" and minimum is 11.5, this should get the job done, as well as, save you money.
Since I have already saved you a grand on your repower, we expect you to buy a round of drinks at the next cruise-out, cheers.
Best wishes,
Marty Chin
Bay Marine Diesel

Gary Mynett wrote:
Hi Marty:

I am emailing you directly because I know you are familiar with BCCs and
Westerbeke engines. As you may recall from my posting on the BCC board, I
am repowering my BCC (hull #064). It currently has a Volvo MD7-B and I am
hoping to replace it with a Westerbeke 35D.

The problem I am running into relates to the engine mount spacing. The
Westerbeke 35D has mounts 14.6" wide athwartships. The rear engine mounts
are just under 14" aft of the forward engine mounts. The result is that all
3 engine mounts fit into the available space with the exception of the aft
starboard mount.

The aft starboard mount runs into the curve of the hull. I was surprised to
learn that the reason for this is that, according to Sumio, the hull is not
symmetrical, such that the aft port mount does not encounter the curve of
the hull whereas the aft starboard mount does.

On my Volvo, the fore-aft spacing of the engine mounts is 9.25", so it
presents no problem. Do you have any experience with repowering BCCs? Other
engines I’ve looked at, including the Yanmar, present the same problem for
me (but are even worse).

My mechanic thinks it should be possible to modify the engine mount so that
it will fit.

I would appreciate any comments you can make.

Gary Mynett

Dear Colleagues:

Sentient, hull # 63, is currently powered with a Volvo Penta 18 hspwr diesel.

Would be interested in hearing the recommendations and experiences of any boat owner who has re-powered. I would like to upgrade to the new Yanmar 29 hspwr, the engine which the company installs in new boats but I am not sure how easily this can be done considering the engine mounts, shaft(currently 3/4 inch), etc.?

Richard A Smith??

Dioscouri, hull #64, originally had the Volvo engine as well. Last Spring, I re-powered with a Westerbeke 35D, which is a 31-hp engine. No modifications to the engine pan were required and I retained the 3/4" shaft.

The engine works beautifully and easily brings the boat up to hull speed with reserve power remaining (with the Volvo, I was unable to exceed 4 knots under power).?

The only complaint I have with the Westerbeke is that most of the service areas are either at the rear of the engine or on the starboard side, and there is little room between the starboard side of the engine and the engine room bulkhead. To help alleviate the problem, I had the engine oil dipstick relocated to the port side (the Westerbeke includes a port on the port side of the engine for this purpose). I have also purchased a remote oil filter, which I have not yet installed but intend to once I can figure out where to put it.?

Gary Mynett


considering our boats are more or less the same vintage highly value your recommendation. If you are comfortable providing a cost estimate that will help when I?get estimates.?

Richard/Sentient ???

Total cost approximated $18,000 Cdn. Engine was about $10,500 Cdn.; various parts (i.e., replaced water muffler; replaced cutlass bearing; upgraded instrument panel; etc.) plus installation labour, yard charges (which approximated $1,000 for the haul out and yard storage costs?for about 1 month)?and excessive taxes (in Canada, taxes are 14% on parts and supplies and 7% on labour) brought the total up to about $18,000.

This was offset by $1,000 sales proceeds on the sale of the old Volvo engine, which was still in good working order.?Shortly after my re-powering, I understand the Westerbeke 35D engine increased in price by about $1,500 in Vancouver due to a change in the distributor.?

Gary Mynett

If you get a Yanmar 29 hspwr, it fairly easy to fit into the
engine compartment - no need to tear out the entry in order to
install it. I took mine out myself without too much trouble.
But, off the subject, if I had it to do over again, I wouldn’t
choose the Yanmar 29 due to my experiences related to oil
consumption, weight, and starting.

Man, if I could use my Volkswagen TDI Diesel in a BCC, I’d be
so happy!!

Mark Gearhart

We have the 3GM30F/27 hp in Shamrock with approximately
500 hours. Currently we have a bent shaft from
flotsam in the delt, it took a blade off; extended
damage to the transmission which now has a rough
bearing. Yanmar diesels 2GM/2GM30F/3GM30F are
relatively good engines as marine diesels go, like
most engine, they have their own short coming.

In particular, the Yanmars tend to shake loose the
banjo fuel fittings at the lift pump and secondary
fuel filters, develop timing cover leaks in less than
1,000 hours, go figure, the seawater pump mounting
bolts are also timing cover bolts, periodic impeller
replacement and belt adjustment caused this joint to
open and close, we have also had issues with front
crank, power take off (hand crank) seals leaking on
low hour engines. Noise levels are higher than on
comparable engines.

The Yanmar Hurth/Kensaki (sp) transmission is
definitely a soft spot for Yanmar, panic shifting from
reverse to forward while the propeller is still
spinning in reverse, generates excessive loads which
tend to deform the output shaft forward bearing recess
in the transmission front cover; this causes the front
bearing race to spin in the cover, causing a growling
sound. Folding propellers also have a similar effect
long term as panic shifts.

Good news MER transmissions in Seattle, WA. has
developed a kit, ZF transmission, keyhole adapter and
drive plate to replace the Yanmar KM2P and KM3P
transmissions at lower cost than replacing the stock
Yanmar transmission.

In the Westerbeke line you might consider the 30B
THREE or the Universal M35B, we have good success with
these engines. Only problem recorded to date has been
a defective glow plug relay which caused the glow
plugs to cycle while the engine is running, the glow
plug automatic breaker to trip and the volt meter to
jump; easy warranty fix, only had two occasions in
last 5 years.

With some of the installations, we have had some
difficulty in changing impellers or accessing oil
filters, non specific to BCC, remote oil filter
(mounted low) and speed seal solved these issues. It’s
not a perfect world, but we managed to work around
these issues.

Best horsepower selection thus far seems to be 3.5 hp
per ton of displacement, any more than this is just
carrying unwanted weight and burning excess fuel. On
our last run with GPS from Alameda California to Half
Moon Bay, we ran at 6-6.5 kts, not a bad run with 27
hp and a 14,000 pound boat.

If you have a boat in the San Francisco Bay Area send
us an e-mail and we will be glad to give you current
Westerbeke/Universal engine pricing.

Marty Chin, BCC Shamrock
Bay Marine Diesel

Sure do appreciate your well informed and thoughtful posts Marty.

Yes, my fuel line banjo fittings (3GM30F) loosen up regularly
too, any solutions, would Lock Tite help ? Not experienced the
leaky timing cover yet at 2000 hrs.

I added the 105 Amp Balmar alternator, and use the Gates Gold Label
cogged belt, but still have a lot of black belt wear powder around
the front of the engine, after long hours of motoring here in Asia.

Would a belt dressing help , I have checked the pulley alignment
thoroughly, already, ?


I’m not Marty, don’t even play him on TV. I do have a 105amp alternator
on my 3GM30f though and fixed my belt wear problem by adding an
additional locking support leg for the alternator. It keeps the case
from moving and hence changing tension. I had the additional leg
fabricated for me by Summerfield Boat Yard in Florida.
I have not had any dust since. I also use an uprated belt.

My boat sat for a year in Houston. Afterwards, black powder was shed
from the belt when under power. In Marathon FL, the mechanic sold me
these small sandpaper wrappers that wrap around the belt. Sure
enough, powder gone! Seems there were spots of rust on the pully
and the abrasion was just enough to cause the black powder.

s/v Godspeed

Belt dust is directly related to:

  1. Improper belt tension and alignment, on the longest length, port side, you should have 3/8-1/2" deflection under firm pressure with your finger; I know that is “firm,” this is subjective at best, use your best
    judgment. To much tension will damage the belt, alternator and freshwater circulation pump bearings, too little tension and the belt sheds burns and sheds
    rubber particles. Use a disposable paint brush and a vacuum to clean the timing cover, its easy to seeparticles forming with a clean surface.

  2. Improper belt size and type. Often called alternator belts, fan belts are also referred to as V-Belts as they form a letter V with the bottom cut off, the sides of this V form an angle, its important to get the proper sized belt with the correct angle to match the pulleys on your engine. It is also important
    to match the pulley grove angle when adding a non-stock pulley as in adding a high-output alternator. We prefer to use industrial quality belts, they look cloth wrapped and tend to last longer and shed less if tension is not absolutely correct.

3 In some cases corrosion in the pulleys (shame on you). The 3M cleaning pads, synthetic sand paper works well.

  1. Loose alternator mount brackets, worn mounting ears, and weak bracketry which allow the alternator to move out of alignment when running will also cause the
    formation of belt dust and excess wear.

  2. Cogged belts work incredibly well, but setup and tensioning is critical to preventing excessive wear. When set up properly they will outlast the V-belt

Yanmar fuel banjo leaks: Best thing to do is check banjo bolt tension periodically and replace the copper crush washers (seals) every couple of years, they are cheap; as the name implies “crush” they are deformed as you tighten the fittings, continuing to tighten over a number of years will compress and harder these washer to a point where you can not stop the leak without excess torque, don’t do it, buy and install new washers.

Best wishes,

Marty Chin, BCC Shamrock.