Repowering WHOOSH
our 1979 Pearson 424 Ketch

The intent of these notes is to hit some of the highpoints in what we learned when removing our Westerbeke 60 diesel from WHOOSH and replacing it with a new 4-cylinder diesel. It will no doubt miss a lot of the details and anyone interested is invited to contact me for additional comment (n3fyp@winlink.org will work the best, long term).

This was my second repower. What I discovered the first time with an older H-R 35 was that, unlike most equipment purchases for a boat, you don't really buy a "repower". You may be shopping for an engine swap-out and expect the vendor to be at the least knowledgeable about all the related issues; in fact, you may hope he'll embrace them as his own. But engine dealers usually seem far more prepared to sell you an engine than talk you through the many issues you face when picking it. In other words, this is usually not a ‘turn-key' purchase – no matter what you hear from the guys in the Blue Blazers at the boat shows - and it left me, even this second time around with WHOOSH, a bit anxious.

Devil's in the Details: To get specific, here are some of the 424 issues I wrestled with while in the process of deciding to repower – along with my own thoughts & conclusions:

New engine or rebuild the old one? With a W60, rebuilding didn't seem like a good idea – some major parts are difficult to find these days, perhaps even no longer available. What would it be like 5 years from now, if I needed a new head for my rebuilt W60, perhaps while I was in the Med? If you have a later model W58 in your 424, the choice may be more difficult since parts are more readily found…but you'll need to look closely at how you'll be using your engine. Local sailing with a good mechanic and the U.S. supply chain nearby, a rebuild could be less comprehensive I suppose. Just don't overlook the large number of peripheral pumps, plumbing, electrical components, manifolds and their respective seals, gaskets and fasteners, all past their prime. Have you priced a cross-section of parts? If you replace/rebuild the peripherals in addition to the major internal rebuild, how much will you save over a new engine? And how much of that rebuild cost will you recover when/if selling the boat?

What engines do you get to pick from? This is like solving one of those multi-variable algebra equations back in junior high. First are the ‘physical fit' issues: the new engine needs to sit on your old bed, or a bed modification needs to be folded into the work & budget. The linear geometry needs to work: How will the new transmission flange mate up with the old tubular jackshaft of the V-drive? What about that cabin sole joist just above the aft end of the jackshaft? Will everything fit under the old engine box and with sufficient room for the new oil pan & its remote drain line to clear the hull. And of course, how accessible will the raw water pump, oil & fuel filters, belts & their adjustment points, and bleed points all be after it's in and the hoses are run? Second is the issue of power (torque curve & shaft rpm/hp curve), as marine diesels have come almost full circle since our 424's were first built. Diesels used to be big, slow-turning and heavy – e.g. my W60 continuous duty rpm was 2500. Then the EPA introduced emissions standards which engine manufacturers initially began meeting by running their engines at higher rpms – meaning the horsepower you may want is now being produced at a much higher rpm. More recently, some manufacturers (Perkins, Cummins and Westerbeke are examples) have begun introducing engines with lower rpm/hp curves. Your prime focus will be on the shaft hp which the prop sees and what this means for the engine's rpm and fuel consumption, given the gear ratio provided to you by your existing (or new) V-drive and transmission. Chapter 5 in Nigel Calder's Cruising Handbook and also Dave Gerr's The Nature of Boats are good references for thinking these issues through. In fact, Calder's thorough review of what displacement actually means aboard a boat used for cruising is also worth reviewing – see Chapter 1.

"In for a penny, in for a pound." If your fuel tank is original – or even if it isn't – you'll face the opportunity to easily replace it while the old engine is out vs. the more difficult prospect of changing it later should that be necessary. You can also redesign it in the process, which might include adding a clean-out port, rerunning the vent so your boat doesn't discharge fuel overflow into the water, complying with new return line requirements given by the engine manufacturer, and whatever else strikes your fancy. Also, don't overlook the fact that, if you are replacing the tank, it becomes the gating item in the repower sequence: it comes out last but must go back in first. FWIW I tracked the cost of having a new tank built and installed (as with the engine change, I did the grunt work but relied on good tradesmen for the important stuff) and it cost me $782 including new fittings, hose, different vent system, new metal restraints, fuel gauge, and the transport of the tank. This is not a huge sum when compared to the total cost of the repower, and is no doubt offset to some extent by the later cost & hassle of moving the engine should you need to repair/replace your tank. (Of course, you WILL replace your tank some day, if you keep your boat long enough). Also in the FWIW Department, after making the new tank 1” shorter so it would fit through the companionway (unlike my old tank, going out) I incrementally added fuel in 5-gallon increments in order to calibrate the new gauge to what the tank was actually holding. I found the new tank’s capacity to be just shy of 80 gallons, almost as advertised.

You'll also may choose to face the issue of your V-drive, namely is the 2.05:1 ratio of the RV-20 compatible with your new engine (again, given the shaft rpm you need for the shaft hp you'll want) and/or is it time to replace your older, perhaps tired RV-20 with Walter's current-model RV-26, described as a near drop-in replacement. The V-drive's gear ratio is the only issue forced on you at this time by changing your engine. I noticed my 23-yr old RV-20's cooling galley was slowly going away (one of the fins had broken off; the cast-iron top was flaking away) and I priced a total rebuild by Transmission Marine in Ft. Lauderdale, including a new case and manifold cover given the cast iron issues as perhaps $500 cheaper than a new RV-26. Because of our cruising plans, I opted for the new unit (which I have ordered but not installed as I write this). At the other extreme, just rebuilding the existing gear case will keep your rebuild cost well under $1K.

Should you rebuild or replace your existing transmission? Many of our 424s were originally equipped with Borg-Warner ‘ Velvet Drive' transmissions and every single person with whom I spoke about this issue recommended a rebuild, given no major problems with the unit. In fact, new Velvet Drive transmissions use the same parts as our older ones, so purchasing a new unit doesn't buy you any incremental ‘improvements'. The cost of my rebuild was under $500.

What about your prop? More often than I realized, once folks begin facing the prospect of repowering, they are tempted to address related issues like the suitability of the propeller. I've heard complaints from some 424 owners about handling the boat in confined spaces and backing power with its stock fixed 20 x 13 prop but I've been entirely satisfied with mine. (This may be because WHOOSH is the first non-full keel boat I've owned and I find her quite maneuverable by comparison. Or perhaps I've just grown more patient over time). Anyway, if a feathering prop is in your future, you'll find your prop choice influenced by your engine choice (and to an extent, vice versa). I'd just urge you to talk with your probable prop vendor(s) to get a feel for this relationship. I found PYI, the U.S. Max Prop distributor, to be the most helpful info source in my case (800-523-7558). However, this becomes a more difficult puzzle to solve should you want to mate the feathering prop to your existing engine now but also want it properly sized to a new, perhaps not yet identified engine at a later date.

Two Critical Decisions: It may seem a bit counter-intuitive but I was initially more concerned about finding a good mechanic on whom I could rely for a good install than I was on the engine choice. Unlike my first repower, where I relied on the engine dealer to handle the repower, I chose an independent mechanic this time (the same fellow that Tom Bartley of the 424 Cutter UNPLUGGED had started using for his repower). This fellow came highly recommended from yet another 424 owner (Bob Teasely of MISS TEAS) and also my local Westerbeke dealer, even tho’ they also did engine installations. My choice validates getting referrals before making such a decision because this mechanic (Patrick Halbert, St. Pete FL, 727 656-0250) is the main reason our repower went smoothly and why our installation ended up looking a bit like a Swiss watch.

The second critical decision was of course the engine. I wanted the repower to be ‘easy' insofar as that's possible, which meant compatible geometry, appropriate power at the shaft for reasonable fuel economy, a good European as well as U.S. dealer network in case of problems, and a host of other, basically personal preferences (what rpm range I want to normally run in, desire to retain my 2" exhaust system if possible, engine compatibility with my existing HiCap alternator and spare, and other stuff). And it's probably worth noting at this point that 424 engine beds were apparently narrowed down when Pearson shifted from equipping 424s with the W60 to supplying the W58, from a 22.5" width on centerline for older boats to 18.5". Because I'd seen how neat a Westerbeke 71C repower installation was on a 424 I examined in Trinidad, I started with that choice as the benchmark against which to measure the other choices. And in the end, that's what I ended up buying. (The 71C comes with variable width mounts: 18.5/20.5/22.5" so it should fit any 424).

Westebeke 71C Notes: In addition to the compatibility preferences mentioned above, here are a few notes about how this engine worked for my repower and some related choices I made.

As Earl Chappell of PAINKILLER pointed out, the oil filter on the 71C almost sits on top of the engine bed. In his case, it can drop far enough to be removed while in my case I have to cut off a small part of the bed's flange just under the filter. An alternative is to remote mount the filter; the W remote mount kit is quite expensive but can probably be found from an after-market source.

I spec'd double pulleys on the crank and fresh water pump so I could double pulley my small frame HiCap alternator. The dealer thought this would entail an extra $300 as that was the price of the two pulleys in the parts catalog, but Westerbeke provided these at no additional cost, installed at the factory. Perhaps this is their default practice.

Compared at least to my W60, the 71C sits lower and has a more compact form factor; I have more room all around and especially aft of the engine.

The 71C is from that previous EPA-related generation and, while the block is apparently not identical with the W58, it is a similar Mazda block which Mazda approved running at a higher 3600 (vs. 3000) rpm. I don't need a 71 hp engine, nor will I need to run this engine anywhere near 3000 rpm for an extended period, so I saw the purchase of a 71C as equivalent to buying a ‘new W58' no matter that Westerbeke now called it a 71C. (The torque & rpm/hp curves appear identical for the W58 & W71C up to 3000 rpm). The torque and power curves suited me for the rpm range I intended using and, as a result, I didn't see any reason to increase the exhaust system from 2" to 3". We'll see how this works out in reality but distributor/engine dealer/mechanic all support this logic given my self-imposed 3000-rpm limitation.

Exhaust can be discharged from either end of the 71C manifold, although Westerbeke will routinely route it off the transmission end of the engine ("forward" in our 424s) unless a special manifold casting is spec'd when the order is placed. I was counseled by the Miami distributor and also my engine dealer that, again somewhat counter-intuitively, needing to run the exhaust hose to a muffler can immediately adjacent to the manifold may not be as easy as I thought, and to consider an elbow and the normal exhaust routing. In the end, I ordered an optional 3" to 2", 90 degree exhaust elbow from Westerbeke that mates directly to the 71C's exhaust elbow. It is not reflected in their engine parts list but is referenced in the 71C generator parts list. That elbow plus a 4' run of 2" exhaust hose mated up nicely to my existing muffler can. (I'd been using a relatively new, large muffler can, approx. 12" diameter by 12" tall and this turned out to be the recommended size for the 71C). What I thought was one of the major liabilities of the 71C – lots of raw water, heater to/from and exhaust hoses all running down the port side of the engine and creating access issues – has turned out to be a non-issue.

The raw water pump's impeller cover plate, again as previously documented by Earl, is not located in a user-friendly spot (at least for our 424s) and access to the water pump mounting bolts is difficult. So far, I consider this the one ‘fit' disappointment in this engine's selection and I have two options. I can live with it and get the right tools (namely a ratcheting 9/16" box end wrench, as Earl recommended) and adopt the right attitude – this is my current choice – or I can install a remote-mount 12V raw water pump such as is often seen on generator installations. I think there are several disadvantages to this latter choice but it's a viable one.

I ordered a new instrument panel with the engine, something I debated since I'd changed just about all the gauges on the old panel. In the end, the old wiring was what led me to choose the new panel. If I hadn't made this decision, I would have had to wire up the old ignition switch in order to operate the 71C's stop solenoid. Also, the 71C start sequence is different and that may have entailed some additional wiring. As it turned out (it's only money…) I was glad I opted for the new panel as the new wiring is much simplified and the shin-banging invited by the old shut-down release on the side of the cockpit well has now gone away.

Earl previously described a mechanical hook-up problem with his transmission linkage but I wonder if that was due to him buying a new transmission along with his 71C engine. In my case, hooking up the old B-W transmission meant the old cable worked in the same manner.

Finally, this turns out to be a LOT of engine when it comes to powering. We have yet to experience it in head seas, against a current and/or when motoring into a stiff wind…but in still water, we were amazed at how easily it moved the boat (7-7.5 kts at 1500 rpm; 8.7 kts at 2200 rpm, both in still water as measured by GPS with adjustment for tidal current). This may be in part due to the fixed 20 x 13 prop that, down low on the rpm curve, is doing serious work. We'll know more once we install the Max Prop.

In the end, I'm very pleased with this engine choice tho' obviously it's not the only viable one. You could well weigh the variables & identify the needs differently than I did, which is why I have steered clear of comparing the various engines I looked at – beauty is in the eye of the beholder.

The Swap-Out: Due to Tom Bartley's hospitality, we did this engine change while at his private dock and not near any crane or boatyard facility. An original plan – using a truck-mounted crane at a nearby vacant lot – fell through and we were all left scratching our heads. In the end, I got a dock builder who operated a small barge & crane to talk with my Wunderkind mechanic and we collectively developed a plan for mooring the barge alongside WHOOSH, craning the old engine out and barging it to a nearby boat ramp. At the ramp, the old engine was momentarily set aside while the new engine was craned out of the mechanic's van and onto the barge, then the old engine was craned into the van for later shipment to Rich Carter up in New Hampshire. Finally, the barge craned the new engine into WHOOSH. I mention all this because the lesson I learned yet again is that necessity really can be the mother of invention and that you might have a more economical option available to you than you realize or than is conventionally used in your area. Of course, this also worked because the two barge operators, tho' very young, had quite soft hands on the controls and, just in case I need to say this one more time, my mechanic was very, very good with this kind of incidental stuff that we never think about initially when planning a repower.

Surprises: Fortunately, they were few.

My fuel tank didn't fit through my companionway, even after two nearby 424 fuel tanks had easily come out. (My very first post-purchase piece of advice from a fellow 424 owner came from Hal Sutphen, who explained that no two 424s were built exactly the same. That observation has resurfaced many, many times). We had to do some cutting to get it out, which is when you learn just how much residual fuel you weren't able to pump out of the old tank.

My W60 really didn't want to come out through the companionway either, not because of width but because of its combined height-length. We'd slinged it at a significant angle, bell housing end down and tranny removed, but in reality it needed to dip even further. I swear to this day that, at the critical moment, I saw WHOOSH expel a deep breath and the companionway ‘relax' just a bit. All's well that ends well.

No hot (or even tepid) water from the hot water heater, not even after 2 solid hours of motoring. This is when my dealer came through again – he called a really nice fellow at Westerbeke whom I'd met at the local boat show and who's apparently ‘the guy' on W engines. Joe Joyce (Nat'l & Int'nat'l Service Manager, 508 823-7677) sighed and wondered out loud why Engineering hadn't made ‘that change' yet, then sent out an adapter plug that permits sending engine coolant to the HWH from the high pressure side of the thermostat vs. where the manual says to route it from under the manifold. (We'd already verified that there was essentially no coolant flow to/from the HWH). We'll see what difference this makes, but it's gotta get better!

Deserving of special praise: In addition to Patrick Halbert, two other sources of information proved especially valuable to me. One is Tom Piper, one of the people at R.B. Grove in Miami, FL (305 854-5420), the Westerbeke distributor for my area. If you understand the supply chain, you'll instantly know this is surprising news – we boaters are not the natural customers of a distributor, who is often worried about meeting dealer needs, not boater needs. Tom is the exception and spent numerous hours with me on the phone, via email and at the SSCA Gam (where I found his presence not only surprising but also reassuring), tracking down all kinds of incidental info about the 71C and several other W models on my behalf with the factory. The other is Yacht Power Products (727 822-2628), my St. Pete, FL Westerbeke (and Yanmar) dealer. This is a father/son business run by Rich and Mike Lloyd and I found Mike (the son/mechanic part of the team) especially helpful in discussing some of the practical details of the new install with an eye to living with the engine and fuel system, long term. While this info may seem mostly irrelevant to 424 owners in the Northeast or Mid-Atlantic states, there are worse ways to do a repower than spending a comfy winter in St. Pete, which is why I mention these details. Special thanks to Earl Chappell, too, since he braved the 71C waters before me.

Again, feel free to pose any follow-up questions that this might stimulate. I may not have the info you need but will give it a try.

Jack Tyler

Written with 5 hours on the Tach, 12/28/02

WHOOSH, lying St. Pete, FL

P.S. Mike Lane was the first Dean of the very first Disney University in Anaheim CA, the training organization that mixed creativity and fun with sound business practices while teaching every employee of Disney, from ride operators to Sr. VP's. All their training was based around a Learning Model that seems to serve many circumstances, including repowering your boat. Here are the 4 stages that Disney would say we must all pass through as we become "proficient" at repowering 424's.

Level 1: Unconscious Incompetence – this is where you are ignorant and, in fact, so ignorant that you don't even know it. Repowering example: Standing in front of the engine booth at the boat show and basking in the reassuring comments of the guys in the Blue Blazers. Listening to smooth comments like: "Ahh, we do this ALLLLL the time…" and "Oh, we repower 424's with this Izuyamawestersomething ALLLLLL the time." We don't ask many questions because we're not really sure what to ask. But we don't think that matters since they seem to have all the answers, anyway. We are so into Level 1 that we don't even notice whether these comments are coming from the local dealer (the guy we'll end up becoming very dependent on for advice, parts, etc.) or from the manufacturer (who is safely buried two levels away from us, the end customer).

Level 2: Conscious Incompetence – this is where we are ignorant and we know it! Repowering example: We begin asking questions that some of them don't know ("What are the different bed width dimensions that this engine can accept?") and graduate to questions that none of them seem to know ("What changes or mods are necessary to install this in a V-drive arrangement, with the engine reversed?" Or "Does it come with an adapter to fit my B-W Velvet Drive…and if not, how much will one cost, and can you provide it?") The problem with Level 2 is that, while we are wising up to the issues we must face, we don't know the answers any more than they do. And so we begin digging…

Level 3: Conscious Competence – this is where we begin to understand the issues (engine geometry, shaft hp vs. rpm vs. fuel consumption, hose runs will need to go ‘from here, to there', etc.) and, much quicker than we'd like, discover that we are the local expert on our repowering project. Still, this is like peeling the onion as we uncover even deeper levels of Conscious Incompetence which we must eradicate – e.g. learning our new engine doesn't come with a transmission cooler and so we must find a good one and decide how it should be mounted…how? Raw water or fresh? In reality as in life, we find we are constantly cycling between Level 2 and Level 3.

Level 4: Unconscious Competence – this is where you know this stuff without thinking about it, where ‘minor issues' like getting an engine – any engine – out of a boat – any boat – is all in a day's work. I can't say too much about this level because I never reached it. But it was a wonderful day when I discovered that my mechanic was at Level 4 – and of course, that's not true of all mechanics.