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View Full Version : Learning alot about propane conversions


jonathanone
01-29-2011, 07:37 AM
Getting some good info on propane engines, here is what I have learned (forgot to ask if I could quote the source so I will only post the info)

Vapor withdrawal is the best system for smaller engines, fewer moving parts in the carb, larger engines-30hp and up-need the liquid withdrawal system, complicated but this is the only way to develop higher hp.

Any engine can be converted but for longevity the engine MUST have hardened exhaust valve seats, hardened exhaust valves and a cylinder liner. With these the converted engine will far outlast a gasoline version, without the propane engine will have a much shorter life than the gasoline version.

The engine will be derated by approx 8%.

When I asked if there was a brand that converted 'better' than others the answer was, "Honda", interesting since Honda stopped making propane engines some years ago....

ed2hess
09-27-2011, 09:10 PM
[QUOTE=jonathanone;3874034]
Any engine can be converted but for longevity the engine MUST have hardened exhaust valve seats, hardened exhaust valves and a cylinder liner. With these the converted engine will far outlast a gasoline version, without the propane engine will have a much shorter life than the gasoline version.
QUOTE]

And where did this info come from. I don't think any of the engines that are being converted have hardened valves or seat or cyclinder liners. And a bunch are being converted in our area.

sealcutter
09-27-2011, 09:19 PM
I remember going over this a few years back and know the valve guides & seat needed to be changed over to harden, but a cylinder liner. Do you mean change the sleeve out of the block?

Jungle J
09-28-2011, 04:52 PM
Kawasaki engines are made to run on propane as they have all of the stelite components. This is why they up hold their warranty on proper after market conversions. This covers about 70% of the commercial market mowers. Each year at the Kawasaki update schools they have a one hour segment on propane mowers.

ed2hess
09-29-2011, 09:22 PM
Kawasaki engines are made to run on propane as they have all of the stelite components. This is why they up hold their warranty on proper after market conversions. This covers about 70% of the commercial market mowers. Each year at the Kawasaki update schools they have a one hour segment on propane mowers.

They need to work on their oil leaking out of everywhere problems. We got a 17hp converted.

c2weech
09-29-2011, 09:45 PM
Kawasaki engines are made to run on propane as they have all of the stelite components. This is why they up hold their warranty on proper after market conversions. This covers about 70% of the commercial market mowers. Each year at the Kawasaki update schools they have a one hour segment on propane mowers.

I contacted Kawasaki in regards as what was necessary to not void the warranty for a propane conversion. This was the response.

As long as this is installed professionally it will not void warranty at all. More and more units are coming with Propane systems already installed these days. For more information please contact Enviroguard at 1800-858-3533 thanks.


I asked Thank you for the prompt reply. Two follow up questions though. 1. Does it have to be an Envirogaurd conversion system? 2. What qualifies as "professionally installed"?

Thanks again

The last response was It does not have to be Enviroguard, just advising they are an option, and they can answer any of your more specific propane questions, thanks.


Anyone have any ideas what "professionally installed" means? Seeing as they would not specify an answer to this question.

Jungle J
09-30-2011, 08:22 AM
That is correct. Onyx/ Enviroguard conversion kits are EPA CARB certified and must be installed by a certified mech. We offer certification training and fuel soulutions with our program. We convert mowers as well with these kits. You are going to see many of the major mfg jump on this progream with us by the end of the year.

c2weech
10-01-2011, 10:19 PM
I assume this would mean somebody certified to do the installation. Typically this is a four to six hour class including a "hands-on" conversion.

Could I get certified myself to do my own conversions? I am not a mechanic but am pretty handy?

Thanks

djagusch
10-02-2011, 05:46 PM
Could I get certified myself to do my own conversions? I am not a mechanic but am pretty handy?

Thanks

They cannot deny the warranty claim due to you installing it yourself. That is againist the law. If you pushed the issure they would fold. They need to prove it was the conversion that caused the engine failure or your installation.

DR J
10-10-2011, 04:45 PM
Could I get certified myself to do my own conversions? I am not a mechanic but am pretty handy?

Thanks
do not have to be certified to do you own installs by anymeans, only if you are going to sell kits to public.

ed2hess
10-11-2011, 07:42 PM
Well my unit is up and running now I can start collecting some information. I had to get some help since that governor shaft had to be modified to go around the gas inlet tube. Had to have expert to do that. Bottom line a lot more to this than just strapping on some parts. It sure does seem to have more power but maybe that is partly because they adjusted the top speed. Now I am ready for the leaves. No more stalling when the right side of the
machine is high or going over bumps. And should fix the cold warm ups necessary with gas. It ain't pretty but was cheap.....I always go for cheap over beauty. Now maybe we move on to get our trucks converted. Kinda hard decision now that gas is rocketing down.

c2weech
10-12-2011, 04:00 PM
ed2hess the conversion looks good. is that from a kit if so what company or is it through parts that you pieced together? Also what was the cost?

is this your first propane mower?

ed2hess
10-12-2011, 07:21 PM
ed2hess the conversion looks good. is that from a kit if so what company or is it through parts that you pieced together? Also what was the cost?

is this your first propane mower?

No it isn't a kit I begged some parts but had about $300 for the carb, regulator, and switch. Dealer provided probably another $100 worth of fittings, and hoses and some weld work. It is the third unit we have a sentar, a turf tiger on propane.

I just put a short block in this unit it has 2000 hours and I am going
thru it and changing out bearings etc etc. Got a little extra time
these days since no mowing.

ed2hess
10-16-2011, 08:21 PM
Don't judge the merits of propane by the experience of some backyard mechanic choosing the cheapest of methods. I assume many here purchased commercial equipment. ...
I don't work out of a backyard.....and if we decide to put propane on our diesel trucks I will let a professional do it. But not on a six year old machine...And by the way I had a guy looking over my shoulder all the way that is probably one of the best propane install guys around. So what is your point?

djagusch
10-16-2011, 08:22 PM
AND if you still want your unit's warranty to be effective.Is this hard to do? No. Is it hard to do correctly? No. Folks, if you don't know gas, know your gasman.

Don't judge the merits of propane by the experience of some backyard mechanic choosing the cheapest of methods. I assume many here purchased commercial equipment. I also assume you take excellent care of your investment.

Why scrimp now? If you want to try it then for goodness sake do it RIGHT!

FWIW we have distributors re-adjust factory units before they are delivered. Why? Because we want our customers to judge their investment under the best circumstances we can provide. THAT is the reason we are so successful in this endeavor. Compare apples to apples...

For the bold it would need to be a fuel related failure to deny warranty (to lean or rich). If a lower end bearing goes out it would still be covered unless the mfg can prove the conversion caused it. That is the law.

For the red what distributors for factory units? Pace for Scags? Or your propane mowers on your site.

The only thing Ed is missing is an exhaust analyzer to make sure it is running properly. Plug readings, and checking exhaust temps could also make sure it is running right. He got the carb from Kohler directly so it should be pretty close from the get go.

ed2hess
10-17-2011, 09:11 PM
The only thing Ed is missing is an exhaust analyzer to make sure it is running properly. Plug readings, and checking exhaust temps could also make sure it is running right. He got the carb from Kohler directly so it should be pretty close from the get go.
You got me curious.......since I didn't do any of the above except
rpm what do I need to do? The machine wouldn't start after a couple days so I opened the adjusting screw that has a lock nut about 1 and 1/2 turn. It now starts and runs fine at idle and under heavy load. There is an idle screw and a run screw that is caped so I didn't touch neither. Should I expect this propane to run hotter than gas?

This machine isn't being used much so ......I got time to take it back
in to the shop. And to Terry I understand. I need to get more information.

djagusch
10-17-2011, 09:20 PM
We recommend ALL factory units be readjusted before delivery. As far as warranty is concerned that would be between you and the dealer and, honestly, I'm not a lawyer so I can't argue the lawful point. Again, that is between you and the dealer.

An exhaust gas analyzer is fine but how would one set WOT without a Dyno? Our techs use a specialized pressure gauge to set initial and load pressures.

Really, I'm not here to argue with anybody. If I asked a question about lawnmowers or lawnmowing I wouldn't question your authority on the subject. You have too many years of practical application and experience.

I can only share my experience here. How it is used is up to the reader.

By the way, what WOULD the EGT at stoic? I'm curious...

EGT will let you know if the engine is running too hot. Running the engine rich won't wreck it. Running it too lean will melt stuff/expand pistons enough to wreck the cylinders, etc. It should show a lean misfire but if it is right before that point it could seem to work fine but causing damage. Knowing where it was before and after the conversion would be good to compare.

djagusch
10-17-2011, 09:31 PM
You got me curious.......since I didn't do any of the above except
rpm what do I need to do? The machine wouldn't start after a couple days so I opened the adjusting screw that has a lock nut about 1 and 1/2 turn. It now starts and runs fine at idle and under heavy load. There is an idle screw and a run screw that is caped so I didn't touch neither. Should I expect this propane to run hotter than gas?

This machine isn't being used much so ......I got time to take it back
in to the shop. And to Terry I understand. I need to get more information.

The exhaust analzyer is what you want to do if you can. Any motorcycle shop with a dyno should have one. A university in your area may have one also. If you have a ATV shop with a dyno that would be best as the mower can go on it directly.

I'm fortunate enough to have a Polaris project manager as a friend (with a ME degree) and another friend doing emissions research (also ME degree) with the tools (even a atv dyno) needed to check it on a weekend or evening.

ed2hess
10-18-2011, 05:49 PM
Hi Ed,

What regulator did you install? Typically the idle screw is backed all the way off. Run mixture is dependent on the engine.

Some starting problems can be caused by the lockoff not closing and the mixture being too rich.

Yes, since propane is already a vapor it will run slightly hotter than gasoline since there is no "wash down" of the cylinder. It really shouldn't affect operation though.

This may sound like a stupid question but is the tank mounted so that the "pin" is in it's mounting?

Reg is a Beam Model T60...I know about the pin and it is correct.

ed2hess
10-21-2011, 09:38 PM
Also Ed, I talked with my counterpart in TX, Troy, and he tells me McCoy's Equipment is well versed in Propane Carburetion. Perhaps a trip by there could help?

Bottom line is: we want folks happy with using our fuel. If you don't have the right parts we can get them.

Actually Jimmy worked with me finishing the connections a few weeks ago. I train at that shop every other week so I can do the repair on our equipment in the field. I will take it bye when I get a chance I was trying to get some feedback to get it started the next morning. I figured out which one to get a little more gas and it started but will drop if bye for him to check it. Thanks
I don't plan to get certified.

Propane Guru
11-02-2011, 11:28 AM
Not all engines are derated, some actually increase in HP. It depends on the kit used. Propane has 104 - 108 octane rating which is the power but has less BTU's which is the energy.