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Author Topic: DES 8/1 Propane Conversion project  (Read 66489 times)

Tom

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Re: DES 8/1 Propane Conversion project
« Reply #225 on: November 30, 2016, 06:02:26 PM »
Before you reduce the lash, consider that as it's operating now, there is an explosive mixture in the intake.

I had bought a LP Onan RV generator for backup power at our previous home. It was the good old days when LP was $.61 per gal. In firing it up the second time, I guess the LARGE muffler was filled with the perfect LP/O2 mixture and it went off with a thunderous boom. My 8 year old son about soiled is shorts.

I'd hate to see this happen to an air cleaner full of LP because it will probably be blown to bits.
Tom
2004 Ashwamegh 6/1 #217 - ST5 just over 3k hours.

BruceM

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Re: DES 8/1 Propane Conversion project
« Reply #226 on: November 30, 2016, 10:08:00 PM »
Yes, I'll make sure we don't have any propane in the air cleaner.  It shouldn't be an issue for the small leaks since the intake's big gulps of fresh air will purge it continuously.


gusbratz

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Re: DES 8/1 Propane Conversion project
« Reply #227 on: December 01, 2016, 04:01:13 AM »
The stationary gas engines I worked on for the gas company were air start meaning there was an air starter on each cyl and an air distributor to time the air introduction. we would start the engine spinning then once it was up to speed  introduce gas to the mixing valve. once it fired we would shut off the air.  it was like 2 handles attached to 3 way valves and it had the same feel as switching over an old gas start IH dozer from gas to diesel. sort of that satisfying feeling as it came alive.

BruceM

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Re: DES 8/1 Propane Conversion project
« Reply #228 on: May 09, 2017, 02:59:22 PM »
Just a status update. 
The 8/1 spark/propane converted engine has been running well and strong for the last 500 hours of run time, mostly pumping air for my air table saw and hand circular saw and such borrowed by my neighbor for his home construction, plus domestic duty running the submersible well pump and washing machine. The large diaphram KN (Garret) regulator has been reliable and combined with the large diaphram CA110 carburetor (thanks Gary) is the solution to the "big intake gulp" of the Lister CS clone.  No more leaking gas smells since we added an old MB air filter and housing and connected the regulator vent back into the air cleaner.

I'd convert over my own engine to propane except I'd need new flywheels to do it.




veggie

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Re: DES 8/1 Propane Conversion project
« Reply #229 on: July 12, 2018, 06:43:28 PM »
BruceM

3 questions regarding the conversion...

1] How were you able to get a negative inlet pressure in the intake manifold in order to activate the propane regulator?
Does the stock diesel valve timing produce enough vacuum or did you have to alter the valve timing?

2] Are you still using the compression release to start the engine? or do you crank it under compression like a regular gasoline engine?

3] Did you lower the compression ratio ?

Sorry if this was discussed earlier, I must have missed it in the previous 15 pages  ;)

cheers,
Veggie



- 6/1 GM90 Listeroid - Delco 33si Alternator
- Changfa R175 - Lease/Neville Alternator
- Kubota Z482 - 4kw
- JiangDong R165 Air cooled - 2 kw

BruceM

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Re: DES 8/1 Propane Conversion project
« Reply #230 on: July 12, 2018, 07:07:06 PM »
Hi Veggie,
1. I used a CA110 propane carburetor.
2. Still use the decompressor for starting since we're using a relatively wimpy Gast 4am w/rubber roller starter.
3. Yes, the compression was lowered repeatedly to where we had no knocking at full load. A total of 0.6 inches of aluminum spacer and gaskets. I believe we could have a bit less since changing to the Garret KN type regulator. That regulator also make the carb rich/lean adjustment work properly.  To accomodate the 0.6 inches of head raising, I added to the length of the shorter pushrod, and moved the longer pushrod to the shorter position.

Yes, all this is covered in the prior pages.

The engine has logged around 700 hrs so far, and has been problem free.  The oil stays in pristine condition, looks like it just came out of the can.  Mostly it's running the air compressor for construction projects, plus generator (ST-3) for well pumping while running the washing machine.  Someday I'll get my air skill saw back. :) 

I'm happy with the result.  My health and enthusiasm for non-essential projects is waning or I'd do mine.  My neighbor is happy to not be hauling and handling diesel fuel.  It's pumped into his main propane tank which serves 15psi gas to the pex-like plastic distribution lines, down regulated at the engine room, shop and house to 10 inches of WP.