My three phase power solution

Alternative energy sources
Forum rules
The usual. As I have two large solar PV systems here, and my lab assistant just put one in, and others are interested in things like this, here's where that stuff goes. This is mostly for things that work now, not "gee someday a fusor will do this" -- we know that, but it's not someday yet.
The hope is to save anyone embarking on this sort of thing a lot of wasted time and money, as at least I have been off the grid since 1980 and have had a lot of practice (and made mistakes you won't have to).

My three phase power solution

Postby Jerry » Sat Sep 12, 2015 1:21 am

Wednesday I drove up to Marysville, WA from Beaverton, OR to pick up an old PU-26A/U genset that was on craigslist. Apparently it has been serving as a standby generator at the Lake Goodwin Fire Dept up until about 8 years ago when they finally got something newer. It has been converted to propane with a Century valve, regulator, and carb. They guy I got it from got it from the guy who got it from the FD and he managed to get it running. I paid $550 for it.

It needed new hoses bad, it has the M38 Willys engine in it and the little bypass line was rotted though. I replaced all those lines and installed a new fan belt. I pulled the thermostat off and checked it, old bellows style, still works. But I just couldn't keep the thing running. Eventually found the propane hose was full of dirt, some bugs must have decided to try to make a nest in there.

Video of first run, generates just fine.



I noticed some noise in the exhaust, today I traced down a couple errant wires, picked up some Automate 2245 plugs from Napa (Less than $8 ea!), and popped the side cover off and adjusted the valves. There was little or no lash in every exhaust valve. Put it all back together and it seems to run smoother.

Next thing to do is to build an exhaust system, Does anybody know id the M80 engines used 1-1/2" or 1-3/4" exhaust? I looked it up and couldn't find anything.

Jerry
 
Posts: 556
Joined: Sun Jul 18, 2010 1:07 am
Location: Beaverton, OR

Re: My three phase power solution

Postby Doug Coulter » Mon Sep 21, 2015 9:39 pm

Dunno. For the lister, which was like having a full-auto machine pistol running in the backyard at 7.5 hz, I just bought some pipe and a walker muffler from summit and did a bit of welding...works great. Now it's a thud instead of a bang.
They only had SS pipe in the size/length I wanted - as it turned out, regular steel in the shortest size they have - would have cost me more due to shipping than the shorter pipe I wanted in SS...so...why not?

I got the walker muffler due to complaints in the reviews that it made people's hot rods too quiet...yup, just what I wanted, no complaints here. There has been some backing and forthing around making this all "shake" together with the engine - so things don't work-harden or pound out what were NPT threads in cast iron in the Lister, but those are mostly solved. Don't count on a stiff mount on a long lever arm, or a bellows for this - it will break rather quickly. I used some struts to brace things.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
User avatar
Doug Coulter
 
Posts: 2964
Joined: Wed Jul 14, 2010 8:05 pm
Location: Floyd county, VA, USA

Re: My three phase power solution

Postby Jerry » Tue Sep 22, 2015 12:30 am

I have since found that this generator and the much, much more common PE-95 generator use the same exhaust. They get parted out from time to time and I can probably pick up what I need eventually. I did find a NOS muffler for it on ebay for about $36 shipped.

Got the new valve and guide installed this morning and it runs fine. I do have a little of what I think is pinging and from what I hear it might be from either timing is too far advanced or the propane mixture is too rich. I am going to have to play a bit.
Jerry
 
Posts: 556
Joined: Sun Jul 18, 2010 1:07 am
Location: Beaverton, OR

Re: My three phase power solution

Postby Doug Coulter » Tue Sep 29, 2015 10:02 pm

Take this with a grain of salt, as I have no experience with propane IC engines, but lots with gasoline and some with diesel (the lister, now).
Gasoline has a curve of ideal timing vs mixture - on either side of peak burn speed mixture, it's slower and it has a very definite peak burn speed at some mixture. I've used this trick on street-strip cars.

Basically, you use a super lean mixture (and a killer ignition system like MSD) on the primaries of a spread-bore. Then a super rich mixture on the secondaries. They are about the same best timing on either side of "the fast burn peak", and in a spread-bore, the primaries are essentially a tiny vacuum leak when the huge secondaries are open - you get about 2 pings during the transition. Further, on a hot rod, once you get the rpm's up - it matters less as it simply doesn't have time to "ping" before the piston is heading back down anyway (some guys in NASCAR ran ridiculous compression ratios - I heard of 17::1 - bordering on diesel - and got away with it due to that, especially in the restrictor plate days - and with cam timing that made the *effective* compression ratio low at low rpm - a slick trick). Obviously in a fixed-plant engine, you're fixed rpm and must tune for just that, though.

You might be right on the peak. In that case, it's not just "too rich" - you could go either direction and slow down the burn rate, or of course, just change the timing, depending on which is easier...if propane works at all like gasoline (I think it might).
If you're like me, you'd go leaner, as you imply - why waste fuel?

I was running 16.5::1 (air/gasoline) on the lean side with gasoline, and <10::1 on the secondaries. The peak was somewhere around 13-14::1 for gasoline. It was so lean on the primaries that without an MSD ignition, it wouldn't even run at all, not even a pop. But it ran like stink...and got great mileage (high 20s) for the period on a big block engine if you kept your foot out of it unless you really needed/wanted ridiculous power. If you put your foot in it, it was more like single digit mileage...but fun.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
User avatar
Doug Coulter
 
Posts: 2964
Joined: Wed Jul 14, 2010 8:05 pm
Location: Floyd county, VA, USA

Re: My three phase power solution

Postby Jerry » Wed Sep 30, 2015 2:14 am

I played around with the mixture and it quieted up quite a bit. I actually had to do a bunch of adjustments after cleaning the heads and stuff, it would not come up to speed, the velocity governor was kicking in way to early. This was also what was causing it to surge on startup.

The new muffler showed up last week and I went to the local muffler shop where they sold me a mating flange for the manifold for $5. Picked up some 1-1/2" fittings and a rigid conduit sweep and replicated the old exhaust piping. I got lazy and just silver brazed the parts together.

It runs very well now. The noisiest thing about it is the radiator fan, it really blows. The leaves on the trees 20' away are dancing in the wind from it. Next thing is to make up the two missing covers and it will be pretty much done. I also need to replace the propane lines. They are getting a but hard.

Jerry
 
Posts: 556
Joined: Sun Jul 18, 2010 1:07 am
Location: Beaverton, OR


Return to Alt energy

Who is online

Users browsing this forum: No registered users and 1 guest