The GM-90

[Procrustes]

I've just recently learned about the Satyajeet GM-90.

Here's a summary of what's different about it and other Listeroids:

	GM-90	Listeroids
Lubrication	Oil pump and splash	Splash
Cooling System	Water pump and thermosiphon	Thermosiphon
Injection	Direct	Indirect
Balanced crankshaft	Yes	No
Balanced flywheels	Yes	Not usually

For someone like me who is not too nostalgic, the GM-90 seems like a better choice on paper.  Lots of people choose other models though.  For what reasons did some of you folks reject the GM-90?

If you look at this picture from listeroids.com:



you can discern what appears to be a chain drive to power the oil and water pumps.
 
On a side note, does anyone know how easy it would be to add an automotive oil filter to the GM-90?  Of course I mean no disrespect to the hard-hitting new Hotater splash filter.

[rpg52]

No pretense that I am an expert, but, a few of the things I considered:  1) PS listeroids have an oil pump and are balanced at the flywheel (+ or -), something wrong with thermosiphon cooling?, I hear tell indirect injection is better for alternative fuels, aluminum pistons may have other drawbacks, esp. if the engine sits around for some period, all iron engine parts are more traditional?  Also, parts for most Listeroids are interchangeable, it seems like many parts for the GM90 would have to be obtained from the sole manufacturer.  Only my $0.02     I would hope your question isn't in the form of an advertisement for this particular brand of Listeroid?  No offense intended - from everything I have heard they run well, but there may be other considerations involved. 
Ray

[jimmer]

I have a GM-90. Great engine.

That's a multi-link leather belt, not a chain.

It drives the water pump. The oil pump is internal.

Jim

[kyradawg]

 Check out Mikes web site http://listeroids.com/ he is in north cakalaca and sells the gm-90's has over $10,000 in spares and has been importing listeroids longer than George from utterpower. Peace&Love, Darren

[GerryH]

Procrustes
IMHO,
if you have thermosyphon, why do you want a pump? so you have something to leak and repair? And you need a chain drive to oil and replace, fer shure.

Splash worked on my '53 Chevy, on the Lister for 50+years, and it still works on my Tecumsah 3600rpm rototiller. BTW, I have an oil pump on my PS 6/1 and don't need it, so I might rig up a toilet paper filter to give it something to do to justify the power it consumes.

Balance, yes. I preferr not to have crank weights as I got big paws and I get them tangled up in weights. The whole assembly, crank and flywheels can and should be balanced as a unit when made in India. If you have a weighted crank and balanced to racing specs, you gonna hava hopper if the wheels are out of wack. The wheels can be balanced to do the whole thing.
Case 850B engine, VW Rabbit diesel, are a few of the modern engines that do not weight the crank. VW used weight on the flywheel and Case went to counter-rotating weights on a separate shaft.

My personal choice is not to have a aluminum piston, as the GM 90. For slow burning fuel,  as WVO, a pre-combustion system is better and a cast iron piston expands at the rate of the block. Aluminum expands at 2.5 times the rate of iron, so you have to have a slop fit til it gets warm. The other important thing is cooling the aluminum piston. All diesel engines with alloy pistons have oil jets to cool the underside of the piston. Aluminum melts at 1200 degreesF and exhaust gas temp in a modern engine under load can easily exceed 1200 on the pyrometer. I has seen this many times.

Anywhay, thats my 2 cents worth.

Gerry

[BruceM]

I"m not sure I believe that one India manufacturer/assembler has been consistently putting out perfect units for years.  This seems inconsistent with every other importers experience.  Because of freight costs, many Listeroids are bought regionally.  I got a quote of $3500 freight from one NE source.

Go check one out in person.  Look at the rocker arm alignment, rocker wear surfaces, valve stem cap surfaces, and run a finger through the bottom of the crankcase.  Assume the valve tappet faces look worse than the rockers/caps.  While you're in there with a finger in the crankcase, pull off the con rod on the crank (just two bolts)  and take a look at the surfaces of the bearing bushing and crank.

Direct injection I don't like, for sound and problems with WVO/SVO, but Mike says this is not a problem on GM90s because of slow rpm. It is a big departure from the original, and maybe we'll learn more about it's longevity and performance here in time. An aluminum piston I don't like, and I would be slightly worried about getting non-standard Listeroid parts down the road.  Pump for cooling seems unneccessary but convenient. Unless you have over-temp-auto-shutdown, better plumb for convection fow anyway, so why bother with a pump?

Most Listeroids have counterbalanced flywheels, a few seem to have problems there and are "hoppers". My wheels and others have balance drilling marks.  It's good to see a manufacturer addressing this issue seriously though at crank or flywheel is irrelevant, I think.

Ask me in a few years re: splash vs pump.  Pump with a good filter would be nice.

Best Wishes,
Bruce McCreary

[Listeroidsusa]

A major plus over the standard Lister engines with oil pumps is that on the GM-90 the pump is located UNDER the oil level, no priming or run dry problems like you sometimes run into on standard single and twin lister engines, which have their oil pumps located several inches above the oil level. The twins are bad to get an air pocket and stop pumping, and you'll never know it unless you've installed a gage or telltale indicator. I'm not new to the lister engines and have sold many brands over the past 10 years or so, in all sizes from 6-22 hp. so I've got a lot of experience with them. (over 400 sold so far) It just seems like a bad idea to put the oil pump that high above the oil level. True, the GM-90 engines are different than the standard Lister engines, but their updates will, in time I think, produce a more durable engine. The GM-90 engine's oil pump is always primed and has a fine mesh strainer on the pump itself that could easily be adapted to an oil filter.

Mike Montieth

[Procrustes]

No pretense that I am an expert, but, a few of the things I considered:  1) PS listeroids have an oil pump and are balanced at the flywheel (+ or -),

I didn't know that the PS has an oil pump, thanks for mentioning that.

something wrong with thermosiphon cooling?

No.  I'm contemplating radiant heating for the Listeroid waste heat, so I'll need some kind of water pump anyway.

Also, parts for most Listeroids are interchangeable, it seems like many parts for the GM90 would have to be obtained from the sole manufacturer.

That's another concern.

I would hope your question isn't in the form of an advertisement for this particular brand of Listeroid?  No offense intended

If you think I'm a liar then it doesn't matter what I say now, eh?  No offense taken  .

[Procrustes]

I"m not sure I believe that one India manufacturer/assembler has been consistently putting out perfect units for years.  This seems inconsistent with every other importers experience.  Because of freight costs, many Listeroids are bought regionally.  I got a quote of $3500 freight from one NE source.

Go check one out in person.  Look at the rocker arm alignment, rocker wear surfaces, valve stem cap surfaces, and run a finger through the bottom of the crankcase.  Assume the valve tappet faces look worse than the rockers/caps.  While you're in there with a finger in the crankcase, pull off the con rod on the crank (just two bolts)  and take a look at the surfaces of the bearing bushing and crank.

Direct injection I don't like, for sound and problems with WVO/SVO, but Mike says this is not a problem on GM90s because of slow rpm. It is a big departure from the original, and maybe we'll learn more about it's longevity and performance here in time. An aluminum piston I don't like, and I would be slightly worried about getting non-standard Listeroid parts down the road.  Pump for cooling seems unneccessary but convenient. Unless you have over-temp-auto-shutdown, better plumb for convection fow anyway, so why bother with a pump?

Most Listeroids have counterbalanced flywheels, a few seem to have problems there and are "hoppers". My wheels and others have balance drilling marks.  It's good to see a manufacturer addressing this issue seriously though at crank or flywheel is irrelevant, I think.

Ask me in a few years re: splash vs pump.  Pump with a good filter would be nice.

Best Wishes,
Bruce McCreary

About buying regionally -- I hadn't thought of that.  I'm only a few miles away from George, though if memory serves he charges freight from a Portland warehouse (I could well be wrong about this, I talked to him over a year ago).  If Mike is the only guy selling GM-90's then I probably can't get one here on the West coast for a reasonable price anyway.

Are you sure most Listeroids have balanced flywheels?  I've read lots of warnings about hoppers.

Nobody seems enamored of aluminum pistons.  I wonder how much hp they add, or save rather.

I hear you about the standard oil filter.  I want autostart and shutdown for low oil pressure and high temp too.  I've got the variety of laziness where I'll do any amount of work to save myself from tedium.

[DirtbikePilot]

I have a PS 14/1 (JKSON) and the flywheels are ABSOLUTELY NOT balanced. I am going to get them balanced though and I'll let you know how far out they are. I had it bolted to a base that weighs over 1000 pounds and it hopped around like the jackhammer on steriods, base and all!! That's over 2000 pounds jumping around like it weighs nothing and I never got it past about 400 rpm. That's how bad this one is. It is now bolted down with 6 half-inch concrete anchors in the garage and the vibrations go through the entire house. I put a basin of water on the complete opposite side of the house and watched the ripples go through the water and just had to laugh. It has a counterweighted crank and I have no idea why they even bothered. lol...

[BruceM]

Procrustes, if you're only a few miles from George B, it's no contest.  He's been very good to me and I wasn't even his engine customer (he was out at the time). His emphasis is education, and I like that.  He has put a lot of time into his CD which is a valuable tool I was very glad to have in my toolbox as I went through my Listeroid.  (I'm not new to diesels but had never seen a Lister type before.)

I don't know what the general incidence of "hoppers" is. RR ties set in sand under a steel frame or other wood beam mounts seem advised for a big single cylinder engines like these. I'm going with the Jeff Maier approach- 6 rubber pads (5.5x5"x3/4 made from shore A 40 Nitrile rubber sheet stock from McMaster.com, under wood beam frame in my case, over a concrete slab floor in the gen shed (but about 10" thick under the Lister).

I'll be updating my auto shutdown thread soon, keep an eye out. I also feel that's a must for my remote genshed located over a hill from the house site. 

Best Wishes,
Brice

[Procrustes]

I have a PS 14/1 (JKSON) and the flywheels are ABSOLUTELY NOT balanced. I am going to get them balanced though and I'll let you know how far out they are. I had it bolted to a base that weighs over 1000 pounds and it hopped around like the jackhammer on steriods, base and all!! That's over 2000 pounds jumping around like it weighs nothing and I never got it past about 400 rpm. That's how bad this one is. It is now bolted down with 6 half-inch concrete anchors in the garage and the vibrations go through the entire house. I put a basin of water on the complete opposite side of the house and watched the ripples go through the water and just had to laugh. It has a counterweighted crank and I have no idea why they even bothered. lol...

Glad you can laugh about it.  But you know, if you go through George's site he talks about that several times like it's normal.  Then on the page where he uncrates an Ashwamegh 12/2 (IIRC), he notices that the flywheels appear balanced and just fires it up on the crate bottom with no problem.  So I think it's a common problem.  I think you're doing the right thing getting it balanced.  Bolting the machine down may save your sanity, but it's going to waste energy and stress the machine.  Like GerryH indicated above, they really ought to be balanced in India.

[SHIPCHIEF]

That was an ASHWAMEGH 25/2 that George and I cranked up on the pallet base. I was so hooked! I bought one. Well, mine was a hopper. When I started it up on the pallet, the governor was probably set too high, and the engine hopped and rocked to the point that I was almost too afraid to reach for the shutdown lever.
George got a good one, I got a hopper that was full of sand. Oh, by the way, they come with two starter cranks. We thought that was nice of them. Then after a few attemps to start we remembered that they don't give stuff away for no reason. With that 5" bore, you pretty well need two people cranking. So I made an electric start so I would'nt kill myself while adding weights to the flywheels and restarting, then stopping and moving weights and restarting....

[Procrustes]

That was an ASHWAMEGH 25/2 that George and I cranked up on the pallet base. I was so hooked! I bought one. Well, mine was a hopper. When I started it up on the pallet, the governor was probably set too high, and the engine hopped and rocked to the point that I was almost too afraid to reach for the shutdown lever.
George got a good one, I got a hopper that was full of sand. Oh, by the way, they come with two starter cranks. We thought that was nice of them. Then after a few attemps to start we remembered that they don't give stuff away for no reason. With that 5" bore, you pretty well need two people cranking. So I made an electric start so I would'nt kill myself while adding weights to the flywheels and restarting, then stopping and moving weights and restarting....

A 25/2 then, I stand corrected.  "I got a hopper that was full of sand" is a story with which I am all too familiar, even though I don't have a lister yet.

Anyway, how long did it take to balance your Ashwamegh?  How much would you say a flywhel on that thing weighs?  I think I heard that the 6/1 has 150# flywheels.

[Procrustes]

UPDATE: The metex is direct injection, and George says it has an alloy piston.  See http://www.utterpower.com/ps_6_1.htm for George's thoughts on the alloy pistons and direct injection.  The Metex slow diesel page is http://www.metroexporters.com/pages/metex/dieselslow.html.