Criteria

There are a number of engines available on the market that would do a good job powering the 424. I would have liked a drop-in
replacement, but there really isn't one available. All possible replacements require some modification or engine bed changes to work
in this application.

At the bottom of the page is a convenient list of engine manufacturers.

The direction of the replacement engine must be the same as the direction of rotation of the W60. It is not advisable to change the
direction of the propeller pitch to compensate for such a difference. The Pearson 424 has the propeller shaft mounted off-center to
compensate for a tendency for the boat to turn under power. This correction would be wrong if you tried to change the direction of
propeller rotation. It would be possible to correct this in the transmission or in the V-drive. Another limitation is the width of the
companionway hatch; just under 24".

To narrow down the field, I listed some attributes that would be desirable
in a replacement engine. NOTE: Discussions that follow that refer to the front of the engine mean the water-pump/alternator end of
the engine. This would be the front if the engine were mounted in a traditional vehicle.

1. A good dealer network - Parts should be easy to come by and experienced mechanics should be easy to find.

2. Fairly priced parts - Replacement parts are likely to be more expensive than similar parts sold for a high production engine, but
they shouldn't be a magnitude of order more expensive. I'm tired of being gouged every time I need an odd part.

3. High-capacity alternator provision - We spend almost all our time either on the hook or at a mooring. We are almost never tied to
shore power. Although we have engine-driven refrigeration, our power demands are still quite high, about 100AH/day. I've
experimented with solar panels, and temporarily mounted a small generator on the deck. Since we must run the engine for about 90
minutes each day to keep our reefer cold, having a charging system that can charge our batteries in that same amount of time is
highly desirable. Our existing smart regulator and high-capacity alternator meet this goal. It is very large and may not fit on a new
engine however.

Some engines have room to mount a second alternator while others allow replacing the stock alternator with a larger unit. In most
cases, the stock alternator can only be replaced with an 80A alternator or less without overloading the belt. For some people, an 80A
alternator will be sufficient. We rarely have shore power available, so keeping battery charge times low is important. I would find an
80A alternator to be too small. Having been stranded with a failed alternator in the past, I favor having two alternators. This would
allow independent battery and charge system for the starter battery and the house banks. If either system fails, the engine can still be
started. Replacing a stock alternator with a high-capacity alternator frequently presents problems that can be avoided by mounting a
dedicated high-capacity alternator. The stock alternator typically runs with a single belt that also drives a water pump. A single belt is
rarely capable of driving a large alternator. Dual-belts require tensioning to a degree that can overstress the bushings on a water
pump. Even so, I would have accepted a configuration that uses a single alternator as long as it had sufficient capacity to keep up
with our power demands without excessive recharge times. There are other ways to separate batteries and I can always keep a spare
alternator onboard.