Converting from LP to gas(liquid)oline

D

docmirror

Well-known Member

• Aug 2, 2017

• #1

First time through this process. I bought a gas carb, did a rebuild on it, Removed the lower drain port on pressure tank and fitted a gascolator and valve. Doing the fill pipe and cap now.

Is there anything I'm missing? I wasn't planning on a fuel pump as the LP tank is well above the level of the carb.

 

S

ss55

Well-known Member

• Aug 2, 2017

• #1

Many gasoline intake manifolds add heat to help evaporate gasoline in cold weather. Some LPG manifolds don't have that feature. If you need to run in cold weather you may want to check if you'll need a gasoline intake manifold. Make sure your new fill cap is vented.

 

C

cushman

Member

• Aug 2, 2017

• #1

I do not know what engine you are converting,but some LP engines came with too high a compression ratio for gasoline.

 

S

Steve@Advance

Well-known Member

• Aug 2, 2017

• #1

How are you cutting/welding the old tank?

Be very careful!

 

M

mmfan55

Member

• Aug 2, 2017

• #1

You will gain hp using gas vs lp. Depending
on compression, high octane fuel may be
required.

 

OP

OP

D

docmirror

Well-known Member

• Aug 2, 2017

• #1

(quoted from post at 19:03:26 08/02/17) You will gain hp using gas vs lp. Depending
on compression, high octane fuel may be
required.

Click to expand...

Wow, I'm glad I asked here before trying to start it. The LP engine has MUCH higher compression than the gas engine. There's no way the gas will run right with the LP pistons.

Oh well, back to LP.

 

D

David G

Well-known Member

• Aug 2, 2017

• #1

What is the compression ratio?

You should be able to run up to 10:1 with the right fuel, my MH44 is 9.5:1

 

OP

OP

D

docmirror

Well-known Member

• Aug 2, 2017

• #1

Book says 19:1. Way too high for gas. Even if I run avgas, it still might detonate. Either way, the engine won't last. I'll just go back to LP, it was running ok, but my manifold was falling apart.

 

J

jr1983

Member

• Aug 3, 2017

• #1

No way an lp engine is 19 to 1. Probably 9:1

 

S

Steve@Advance

Well-known Member

• Aug 3, 2017

• #1

That can't be right.

You're this close, might as well try. Might need to back the ignition timing off just a little.

 

T

Traditional Farmer

Well-known Member

Location

Virginia

• Aug 3, 2017

• #1

Yea no way its close to that,19:1 is probably the diesel engine compression.

 

BarnyardEngineering

Well-known Member

Location

Rochester, NY

• Aug 3, 2017

• #1

What engine are we talking about? If we knew that someone could tell you what the compression ratio is.

 

R

rustyfarmall

Well-known Member

• Aug 3, 2017

• #1

E85 will handle the higher compression.

 

R

Richard G.

Well-known Member

• Aug 3, 2017

• #1

I converted a 49 LA Case propane to gas about 1996. I talked to a fuels professor at Clemson Ag Engineering before I did. He said it would be fine on regular gas. It ran great and had plenty of power. Pulled a big dirt pan and enlarged a pond with it. Also pulled a disk helping my son farm. That thing would pull Hades of it's hinges.
Richard in NW SC

 

M

mmfan55

Member

• Aug 3, 2017

• #1

19 to 1 has to be a typo. Most diesels are
commonly in the 14 to 17 range. 19 would be
getting in the 500# range.

 

OP

OP

D

docmirror

Well-known Member

• Aug 3, 2017

• #1

JD 2010RU.

It's interesting that all the literature says the diesel is 19:1, and the LP is also 19:1 which has me thinking it may be a typo. I'm going to run a comp test and see what pressure I get, but now I'm thinking that it must be a typo.

If anyone KNOWS what the C/R for the LP engine in the JD 2010 is, I would like to get accurate info.

 

OP

OP

D

docmirror

Well-known Member

• Aug 3, 2017

• #1

OK, never trust the Internet.

I found my I&T shop manual and the specs are in there.

Gas - 7.6:1
LP - 8.9:1
Diesel - 19:1

It looks like I can run gas, and may have to fiddle with the mixture a bit, and timing but I should be able to use good pump gas on the LP engine.

 

S

ss55

Well-known Member

• Aug 3, 2017

• #1

I think sometimes Deere used different pistons for LPG and gasoline versions of the same engine and they used the same cylinder head for both. The (free?) online parts lists would tell you for sure about your tractor. After sixty years of use, overhauls, big piston kits, cylinder head resurfacing, now worn piston rings and valve re-grinds, the compression you have now could be far from stock. At this point a compression test would be a good check.

 

OP

OP

D

docmirror

Well-known Member

• Aug 3, 2017

• #1

Well, that would be a good idea, but this site, and Steiner site don't offer pistons to check the difference, nor do they off full engine kits.

However, I agree with you that the C/R now is likely lower than when it left the factory. I'll just run good 89 gas and set the timing right and watch and listen.