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Old 06-08-2020, 17:54   #1
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Location: Rahleigh, NC
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rebuilding a diesel

Imagine if you will, it's 1985 and Uturn is 15 years old. Now most 15 year old boys in the mid 80 are excited about driving a car. However, I'm nervous because I'm going to be driving and I don't know jack about engines, or any other part of a car for that matter. It's just how my mind works, how can I operate something that I don't know how it works? Not surprising that I became an engineer.

Anyhow, to alleviate my anxiety, Dad and helped me find a car that needed engine work and a brake job. We found a 65 Impala with a 283 with a bad cam. We proceeded to replace that cam and do a full brake job. I learned a ton, and that experience proved invaluable over the years.

Now I have a 1986 sailboat with the original Universal M25. Every time I fire it up, it bugs me that I know jack about it. Other than I don't have to worry about fouling plugs.

I know it still pulls in air/fuel, squish, bang, exhaust, and needs a way to cool off. But I don't know the details. I need details, dammit!

So, where does one go about finding a cheap rebuildable diesel?
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Old 06-08-2020, 18:31   #2
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Re: rebuilding a diesel

ebay has lots of used engines in various conditions. sells used engines and parts. From basket cases to good running engines. They do ship.
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Old 06-08-2020, 20:34   #3
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Re: rebuilding a diesel

There isn’t much difference really, the head is more important on a Diesel, the valves need a better seal at those high compressions, but your better off having a machine shop do any head anyway unless you can grind valves / seats anyway. I like new bronze guides
Pump and injectors it’s my opinion those go to a professional shop too.
If you have wet liners, then no boring or even honing, just check ring gap. If you overhaul before its real bad then most likely the crank can just be polished and go back with standard bearings, most of the time the cam will be fine too as valve spring pressures are low as RPM is low.

Don’t spray bomb paint the motor though, use a high quality ideally two part paint, I like white Marine motors myself.
Replace the oil pump with new, I don’t even measure the wear, pump is just too important and usually not a great expense.

Timing the injection pump can be difficult or dead easy depending on the motor, sometimes it’s possible to time 180 out so be sure it’s TDC compression and not exhaust.

Diesels are really, really easy, especially small inline ones, they are simple things really.
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Old 06-08-2020, 21:37   #4
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Re: rebuilding a diesel

Check local wrecking yards too. Might be able to find and old VW or depending on location a Toyota or Nissan. If you’ve got farmland nearby someone somewhere has an old tractor or similar, check classified (craigslist etc) or ask around. Or if any mining, large marinas or industrial nearby you might be able to find and old diesel genset someone’s ripping/throwing out.
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Old 06-08-2020, 21:39   #5
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Re: rebuilding a diesel

So easy, even a kid can do it...
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Old 07-08-2020, 16:41   #6
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Location: Auckland, NZ
Boat: Compass 790 , 7.9 metres or 26 ft
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Re: rebuilding a diesel

Get a service/workshop manual for whatever engine you wish to do up & that takes the guesswork out of it.
If you can reco a gas engine you can reco a diesel.
If you are happy with your current engine type maybe a good idea would be to buy another one that is not going & rebuild it & swap it out after.
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