Don't be intimidated by the job. I rebuilt my first engine when I was 12 years old, successfully. If I have mediocre mechanical skills now, I certainly had almost none then. It was a Triumph Spitfire with a thrown rod, which my father bought for $50 and gave to me on the condition that I get it running again. It took a couple of weekends.
The hardest part will be getting the engine out.
Here's a taste of what you have in store:
Mike Slinn / Sailing
Parts will cost you $800 to $1500, and you'll have a machine shop bill for a few hundred bucks for grinding the crank, planing flat the head
, doing the valves, and fitting the sleeves. I would recommend having the machine shop -- a good diesel
engine shop -- assemble the block and head
for you -- you'll pay a couple hundred bucks more, but you'll be sure that it's done right.
When you're done, the motor
will be good for another 20,000 hours or so. Provided you fit an oil pressure alarm
, of course.
Things to pay attention to:
* have the block and head checked carefully for flatness and machined flat if necessary
* replace the cylinder head studs and nuts (and don't forget to retorque the head after the first 15 - 20 hours of use)
* replace the oil pump
* make sure the flywheel is flat -- check with micrometer. If not, it can be machined
* crankshaft should be magnafluxed to ensure no cracks
* camshaft may be toast -- cam lobes are sensitive to lube problems. Ditto the lifters. Check.
* don't get the big end caps mixed up -- if they (and the rods) are not stamped with cylinder number, label them carefully as you take them off. They are not interchangeable.
* check the ring gear
. now is the time to replace it if there's any wear
* might as well replace the fresh water
pump while the engine is out
* clean out the heat exchanger
* check if there is anything which can be done about the oil leaks
. maybe someone has come up with some method to deal with it
* send the injection pump and injectors off for bench testing -- this is the time for overhaul
or replacement if they're not perfect
As to repowering -- I can't imagine any scenario where it makes any sense to repower
a boat with a 4-108. There's no way you can repower for less than three or four times the cost of a thorough rebuild, and other than the oil leaks
, a better diesel boat engine than the 4-108 has never been made.
My father's boat, built in 1982, had a broken engine hours clock on it when he bought it in 1994 or 95 -- stuck at 10,000 hours or so. God knows how many hours were on the Westerbeke
marinized Perkins 4-108. He cruised almost full time from then until he finally sold the boat this year -- about 20 years. He must have put on another 10,000 or 15,000 hours at least. He never did anything to that engine but change the diapers in the bilge
to soak up the leaking oil, and change the oil and filters religiously. I don't think he even ever adjusted the valves. Try that with a modern Yanmar