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Onan: Is this little 3 cyl Onan worth my time??

Bear67

Subscriber
Last Subscription Date
02/02/2020
I picked up this Onan with Onan 3 cyl gas engine. It is stuck, but complete. I need to move it so it IMG_1120.JPG is decision time. Should I put it in the project line and try to get it running or do I just junk it. I have a hard time giving up but at my age, I have plenty of projects to keep me out of the pool hall.

I acquired this when we bought all the oil field engines from an old time East Texas Oilfield producer in Kilgore, Texas. Forty engines all under leaky roof warehouses. Sold a few, parted a few and a few are still around
 

Vanman

Subscriber
Last Subscription Date
07/10/2019
Well, first of all, we never junk anything old since all we have is all there will ever be. Give it to someone if nothing else.

It is a Kohler. 1A21 is the automatic ac version, a Model D is automatic dc, yours is a manual dc version, either 1500 or 2000 watt, most likely 115 volt, but could be 40 or 140 for charging a 32 or 112 volt battery. Don’t recall numbers for those, but they’re all very high quality plants. Overhead valve, inline four, 2” x 3”. Works out to ~38 ci. Runs nice and slow, 1,000 or 1,300 rpm depending on which one you have.

Keith
 

Bent Trigger

Subscriber
Last Subscription Date
10/03/2019
If I wasn't loaded for bear in the motor dept I'd have my Nephew in New Bruansfels snag that! Wasn't that free yesterday?
 

Vanman

Subscriber
Last Subscription Date
07/10/2019
It's a fellow on ebay selling gasket kits for these. Asking $185 or some such thing, including shipping. I offered $100 which was accepted, and I was quite happy. :cool: Not sure how many he has, but they're new old stock gasket sets for the military. I'd like to get more, but have to conserve funds.

Keith
 

Bent Trigger

Subscriber
Last Subscription Date
10/03/2019
Keith you have one of these? I would love one but bought a Hit n miss recently, thinking of a Full Monty!:ONot to mention a few motorcycles !! Are thew gaskets for the kohler 4 cyl?
 

Vanman

Subscriber
Last Subscription Date
07/10/2019
The gasket set, yes, just the one. I have resurrected a head gasket for one once. They’re copper with a composite, probably asbestos, sandwiched between, so quite forgiving.

I have two 1A21s, a 1E21, two Model Ds, and an unknown either a Model D or the 2 kW equivalent, a Model K?

Have had one running long enough to play with a little, another running briefly, a spark of life from another. One the engine is internally destroyed by rust, the other two unknown condition, but at least one with what looks like severe rust damage. None of the damage happened while I had them. They all came to me that way, begging for help.

They’re my favorite.

Keith
 

Vanman

Subscriber
Last Subscription Date
07/10/2019
Well, as I like to say, technically it’s possible. But the cast iron pistons are the consistency of wet cereal. A screwdriver just pokes right through them. All the valve heads are rusted off of their stems. I’ve never opened it up enough to see the bottom end. The generator on the other hand looks fantastic, and I’d bet it’s good.

On the outside it’s very original looking, and looks to be in great shape. Built in 1934, it’s my oldest one. It’s really quite sad.

The other rusty one I have not investigated closely, but the exhaust ports are filled completely with rust, so...

The third one that I have not yet investigated closely is not stuck, but some parts have been removed which usually isn’t a good sign.

I don’t scrap any of it. If something is beyond reasonable repair, I figure I can borrow parts from it. For instance I don’t have enough magnetos to go around. The really rough ones might one day be used for experimentation. I’d like to make one higher compression and different valve timing for the same power but greater efficiency. Being overhead valve they’re a good starting point. Probably never happen but who knows. Would be fun.

Keith
 
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Zephyr7

Registered
That is sad. Kinda like the engine version of Alzheimer’s.

How did the valve heads rust off the stems? I’ve never seen that before. Did this engine sit full of water for years, something like that?

Bill
 

Railroads

Registered
If I lived in Texas I'd be interested in saving that DC machine as well.

Machines like that would be good for resistive loads like lighting.

Just don't get me started on the whole incandescent bulb ban. :rant:

None of us ever scrap anything old. What we have now is all there ever will be.

Robert
 

Vanman

Subscriber
Last Subscription Date
07/10/2019
That is sad. Kinda like the engine version of Alzheimer’s.

How did the valve heads rust off the stems? I’ve never seen that before. Did this engine sit full of water for years, something like that?

Bill
All I can tell is that water evidently sat in it for a really long time. In the cylinders, and in the ports. I don’t believe it had an exhaust system on it when I got it, so I don’t know if it got in that way or not. I have thought that the cooling water possibly leaked in to it. They used to just run straight water in them back then, so long as there was no risk of freezing.

Keith
 

Zephyr7

Registered
Just don't get me started on the whole incandescent bulb ban. :rant:

Robert
I wouldn’t be surprised if you could run an LED bulb on DC. I haven’t tried it though.

It wouldn’t actually be that difficult to build a simply inverter to chop the DC output of one of the old DC gensets and run PWM and a lowpass filter to get a sinewave out. If you have a 115v DC set you’re close (ideally you’d want a 170v DC output to feed an inverter). You could use a transformer to step up the low-ish AC voltage you’d get out of an inverter fed with a 115vDC input voltage.

I’ve thought about designing a simple kit of a “brain” for an inverted like this. Cost for parts and a board would be under $100 I think (An educated guess here without a BoM). Do you guys think there would be much interest? The same thing could be used with some extra diodes to get full-power single phase out of one of the non-reconnectable or non-extended stack three phase sets too.

Bill
 

Railroads

Registered
Z,

I've gotten LED and CFL bulbs to run on DC. But they run hotter than on AC. It's just not the same as running Tungsten filament type bulbs. The loading of the genset and the sound just isn't there with the LED or CFL type bulbs. They don't pull enough amps to make the governor crack open either.

Robert
 

YellowLister

Subscriber
Last Subscription Date
o9/30/2019
The gasket set, yes, just the one. I have resurrected a head gasket for one once. They’re copper with a composite, probably asbestos, sandwiched between, so quite forgiving.

I have two 1A21s, a 1E21, two Model Ds, and an unknown either a Model D or the 2 kW equivalent, a Model K?

Have had one running long enough to play with a little, another running briefly, a spark of life from another. One the engine is internally destroyed by rust, the other two unknown condition, but at least one with what looks like severe rust damage. None of the damage happened while I had them. They all came to me that way, begging for help.

They’re my favorite.

Keith
Which one is the one you got from me?? That I bought from a guy at a storage locker in Ventura someplace.. rattle can restore job it was..
 
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