Small diesel engine sourcing?

I'm building a small diesel generator to run waste vegetable oil and am having trouble sourcing an engine. I'm looking for something that puts out anywhere between 15-25 HP. There's plenty online but none I can afford so I want to find one at a salvage yard. Problem is, to search through all the junkyards you need to plug in a make and model of a vehicle, which wouldn't help me at all. Ebay wasn't helpful either. So can anyone offer me some advice as to how to find one? Are there any junkyard databases that allow searching by keywords?
Thanks.

 

The key part of your question is the price. They are available but they demand a price much higher than a comparable gas engine. Part of the problem is diesels and the machines that use them are generally not "disposable" like gasoline engines. So, vehicles/machines and especially their engines are not sent to the scrap yard while still in good condition.

Diesels the size you want were never used in road vehicles so traditional automobile junk yards are probably little help. I would seek used diesel suppliers/rebuilders. They might have a suitable engine removed from a boat or compact tractor. But you should do your research to know what make and series engine to search for. But, none of that helps with the price. Diesels, even used are a bit expensive.

 

That's a great suggestion! Thanks!
I'm happy to spend more for diesel but not brand new prices. I did find some good prices on alibaba but I don't trust Chinese stuff as far as I can throw it.

 

I have a 3 cylinder 16hp kubota diesel I saved for the same reason... just never got around to building it. Look on craigslist for an old Jacobsen front deck diesel mower, kubota gf1800, or something like that. Sometimes you can find one with a bad deck or transmission and get a good deal.

Next, look for a 4 pole generator. Some old motor home generators are 4 pole. 4 pole generators only need 1800 rpm instead of 3600 like a normal generator. That puts the diesel in it's comfort range and allows it to run along quietly, sipping fuel, and increases engine longevity by far.

 

Most light duty engines found in lawn equipment get their rated horsepower at 3'600. Unfortunately slower turning diesels tend to be heavy duty and even more expensive. If you want to go the lower rpm route you can consider a larger engine that you can "derate" by just running at 1'800. The important thing to keep in mind is that you have to look at the engine and generator together as a system.

Here are some output charts for some Yanmar 3 cylinder engines. I like these charts because it shows what the engine can produce at 3'600 and 1'800 rpm and conveniently has marked the output when used for a slow turning generator.

 

My bro in law is a long-haul trucker and for several years used a diesel APU (auxiliary power unit) to run his power & AC when parked overnight. He's now abandoned that because diesels cost so much to rebuild it ate up any savings he thought he'd have vs wear n tear on the truck engine.

Probably not a reason to abandon the idea--but might be good to know before committing.

 

The small compact diesel tractors use the Yamar (sic) diesels, my JD 2210 is rated at 23HP and runs around 2200-2500 RPM.

A lot of China stuff out there also but durability and part availability are unknown!

 

Full bore max rpm for the kubota engines I mentioned is 3200, which is not enough to run a 2 pole generator.

 

What about getting a small second hand tractor & a PTO driven genset?? That way he can run the generator when needed & have the tractor to play, I mean work with when the generator isn't needed???

Roger