850 - Convert from LP to Gas?

Many of you have responded on my other post regarding the vaporizer on my 850. I really appreciate it. From that it appears I have at least a '55 trans with a factory LP system from '57.

Would it makes more sense to convert this guy to gas since the parts for the original vaporizer aren't available? What would that include - tank, lines, carb... maybe manifold?

It would certainly make refueling easier.

Or if I were to go the Impco vaporizer route, where would I start? Parts, manual etc.

Thanks,
Tom

I don't think either would be difficult. Impco vaporizer or similar, the carb and and associated plumbing would likely do it. You could easily use a 30lb or even a 40lb tank, 30lb is common, just install an LP tank cradle like on a forklift to secure it. I would like a 40lb, but full its going to be heavy to lift over the loader arms, so I have one spare 30lb, could use one more actually. The tin will support it and if yours is modified already, why not. Mine just has the hood removed, but this tractor has seen a zillion hours and the tin is not very good on it anyway. The 30lb tanks are not that hard to deal with, get a few, you'll get 4-5 hours run time depending on throttle, and they change quick. Winter time can be trouble if there is a problem with the vaporizer, I cover the engine compartment with a furniture blanket, use that heat to keep the tank warm and I keep the tank I need to use in the heated garage. The oil stays very clean, with the hours I put on it annually, I can extend the oil change interval much more than gasoline, and it seems engine wear correlates to this, they don't wear out nearly as fast. LP I think is less HP, compared to gas, but mine does everything I have needed for in the last 12 years, only using the rotary mower do I notice it bogging down a little in tall/thick grasses, but tolerable, just working harder than other tasks.

On the other side, thats a nice clean model, you could go the other route, source a fuel tank, heat shield, carb, plumbing etc, and tinwork as needed, no tank up top, though mine does not obstruct the view.

Mine as is with LP, just a workhorse anyway, if you were a collector, I suppose making it a factory correct LP may be a consideration, but for work and chores, etc. either way you can't go wrong. LP is nice inside a building, the tanks change out with ease, I've gotten used to mine, and the fuel was cheaper way back when 12 years ago, not anymore, went the other direction, that is for sure.

Thanks Billy - If I go with the Impco vaporizer I should be able to use the factory tank right? Just connect the impco in place of the original?

Billy, your post got me to thinking... I have a Bobcat that ran on propane. The engine is shot and that's the reason I got this tractor when it pulled in next door.

When I looked up the impco model J on the Impco site it looks very similar to the one on the bobcat. I'm going to take a look and see if that might do the trick.

A few of my rowcrops are lp machines converted to gas.... Ditto on how clean I found them when dropping pan and VC and side covers... No varnish even.... Odd. But good!

That's one thing the farmer I got this from mentioned... oil was always really clean. I'd prefer to run it on gas purely for refueling ease but if I can get her going quickly with propane I'll run with that for now.

One thing that concerns me is that I didn't have any trouble at all running this tractor this past winter with it's factory vaporizer. Fired right up on vapor and then I would switch it over to liquid. The bobcat on the other hand I had to keep in a heated garage every winter to get it started. Billy, your problems with the Impco sound a lot like that.

I would think you could plumb it in, but I'm no expert on LP fuel systems. Do a search on the net, there's a lot of information on the LP conversion.

In simple terms, it should be reasonable to assume you could use that tank, get the lines needed to connect everything, and the carburetor. Rego makes the connection hose for the 30Lb tank, there has to be something available to make the connection to the existing tank to the Impco model J.

They do run clean don't they? One bonus for sure, I hate to admit it but I did not change the oil in this 850 from the end of '04 to Sept of '12, it was clear, but started to darken just a little, given the hours per year as well, did not seem to be way overdue either, I run 15w-40 Rotella though.

I have been told with LP engines, you can still see the cross hatch etching on the cylinder walls/ liners, they don't wear nearly as fast.

Aside from aesthetics, I don't mind it being LP powered at all.

Yes, but I think the issue with mine was that it frosts up, even in summer, don't think its getting warm coolant to the vaporizer. If the tank is low, and it starts outside in very cold temps, but won't keep running, except when the tank is low on fuel, its all vapor. Maybe just less than 1/2 a tank. It will sputter for awhile, mine is kept in a heated garage, so I just put a blanket over the engine, run it till it sputters, shut it off for a little while, then it runs without any problems, has to be the coolant issue, might be plugged up from the leak stop I used in the cooling system to deal with that porous block.

Hmmm - Isn't the impco vaporizor external? I know the original that sits in the water jacket/thermostat housing and has warm coolant running past it. The one in my bobcat is mounted to the engine deck.

I converted my 4000 4 cyl over to synthetic oil and for the heck of it checked it at 2years oil anylisis. it was still brand new oil!

I have the oil on the shelf for a change and will do so this year. It's either walmart or kendal full syn oil.. so a cheaper syn oil.. but better than 50's technology.

Any one I go thru that has suffered from stuck valves.. when I put it back together i go to syn oil...

Good to know, helps when you can extend service intervals, of course hours, conditions use, but for the moderate user, it has to be worth it, using oils like you have.

It is, I saw the link in your post, definitely informative about these fuel systems, beyond the layman's perception at least LOL !

If I am correct, there is a supply and return line to the vaporizer, and its the heat from the coolant that provides vapor? I think at least. Mine as is won't sputter in the warm weather, but the vaporizer is frosted up white. I'll either rebuilt it or just get a new one, this one is an older model, like I said, had to be the stop leak or something is not right, when I rebuilt it, 8 years or so back, no trouble at all.

You are correct Billy. I hadn't noticed them before on the Bobcat. It has an Impco Cobra vaporizer and regulator. Going to pull it out and see if I can find the components to hook it into the 850.

I am having a heck of a time finding info for LP on this tractor. Is there a manual I can order? Do you know of a kit I can get minus the vaporizer and regulator?

Thanks - Tom

LP!
I envy you.

It hasn't been mentioned here and to some the cleanliness and extended wear seems like a bit of a mystery. Several years ago when I was selling synthetic to my friend who owned a service station (same man who drove me to pick up my tires the other day) and I was telling him about the beauty of propane. Well . . . several years passed and I bumped into him going into the auto parts store. He says, "Well, I believe you now." I asked what he meant cause I didn't have a clue what he was referring to.

He said, "I took the heads off a 350 chev with 150,000 miles on it that had been running on propane and there was virtually no ring ridge, no perceptible cylinder wall wear -- I thought I was seeing things!"

What I had told him years earlier was that with propane you no longer have less than optimal mixes of air and gas, running rich or the even wetter gas of choke use, [b:8fe6830612]continually washing the oil off the upper cylinder walls.[/b:8fe6830612]

Also there is obviously the no carbon, no varnish factor.

Cheers,
Terry

P.S.
All you farmers running propane are doing your crops a HUGE service as the products of combustion are water vapor and PLANT FOOD . . .CO2!!

In light of this an underbelly exhaust is best with propane.