Unleaded gas in old engines

jason, NW Ontario · Jul 16, 2011

A fellow I know is scrapping his '64 MF combine because he has had to rewire it 3X in the last two years from melted wiring from the manifold. He figures he's been driving a bomb for too long.
How do all the older tractor engines deal with unleaded gas when they were designed to run on leaded gas?
Just curious

Jay

Dean · Jul 16, 2011

Most will tolerate unleaded gasoline so long as they have induction hardened valve seats and/or they are not worked at high output for extended periods (as they were originally designed).

The wireing issue is most likely a design flaw or a timing issue causing the exhaust manifold to overheat. This is usually the result of retarded ignitioin timing due to incorrect static timing or, more likely, a sticking or otherwise faulty centrifugal spark advance.

Ethanol is another matter entirely.

Dean

S.Crum · Jul 16, 2011

I've found that many of the older engines will run hotter on ethanol fuels. I've attributed this to they might be running leaner. I've adjusted my carbs to the richer side and don't seem to have as many heating up issues. The "book settings" have pretty much gone out the window with this new crap they call gas.

onefarmer · Jul 16, 2011

""How do all the older tractor engines deal with unleaded gas when they were designed to run on leaded gas?""

Worst case: They run just fine until the soft seats erode and it needs a valve job. The engine is torn down and hardened seats put in.

At least that's my take on it.

skip33652 · Jul 16, 2011

lead was not added to fuel until after 1923 and was not common until after ww2. Most of the fuel used in tractors or engines would have been cheap or white gas not ethyl which cost more.Paul

IaGary · Jul 16, 2011

I here a lot of talk about losing the lead and ethanol fuel on this board.

Here in the midwest we have been without lead and adding 10% ethanol since the early 70's.

No major issues have resulted and there are more tractors in the midwest than anywhere else in the world. In the 70's the cars were not even designed to burn ethanol and we did it.

Any tractor or engine that has gone bad was about to go bad on regular gas as well.

I know this ethanol thing is new to some you guys around the USA and the rest of the world but it isn't going to hurt you.

It didn't hurt us.

Gary

buickanddeere · Jul 16, 2011

Problem isn't the fuel. The dude is using the wrong kind of wire/wire insulation in a hot/oily environment.
I don't know how somebody can blame unleaded gasoline for melting a wiring harness?

gene bender · Jul 16, 2011

Whats you experience and what valves have you ruined using the gas. I was told the same but i havent had any problems with a 60yr pluss old tractors needing valve job.

Billy NY · Jul 16, 2011

Further west and south, northern New Mexico, well straight north out of Albuquerque 1995 the Indians seemed to have their own oil wells, and appeared to be refining their own. I thought I was seeing things, went to put the nozzle into the rental car, regular..... nope.. Leaded Regular ! Nozzle was much bigger, would not fit, except cars '73 and back. Placard on the pump stated it contained lead. I had always wondered, did they produce this fuel, I did see the wells. Here in NY, no leaded gas since '87 or '88. You remember the last time you saw leaded gas by any chance, things sure are different further west !

John Harmon · Jul 16, 2011

Unleaded Gas will not be much of a problem it's the Ethanol Blend that will be the big troublemaker.Newer vehicles and machines can mostly use the ethanol blends but older machines its a question mark.Here in Arizona Ethanol blended Gas is a fact of life and I never hear of any problems with it. We have strict emmissions requirements here so maybe that weeds out the unfit vehicles. Most Trucks and tractors etc.are diesel any more so the truck factor rules out a big percentage of the vehicles on the hiways.

bob15 · Jul 16, 2011

Leaded and unleaded gas run at the same engine and exhaust temp. The problem is someone is wiring it incorrectly.

Anonymous-0 · Jul 16, 2011

On my TEA20 I use an additive from Shell to protect the valves, 10 ml per litre.
Some of the old engines will work fine without it.During the changeover here [Oz]there was a list published which listed the engines which were ok without.Don't have it though.

Will Herring · Jul 17, 2011

I have a quart container of "FS Valve Save" that some salesman gave us as a promotion long ago when they quit carrying leaded gas (late 90s, maybe?)... You use such a small amount, and we only run our tractors so rarely, that there's still 1/3 of the thing left. Don't know if it does anything, really, but it looks like adding a teaspoon of motor oil to the gas. No engine problems to speak of, at any rate (in my old AC WD).

Spook · Jul 17, 2011

Never hurt my 48 H, 300U, or my neighbor's 74 3/4 ton truck. Or any other engine I know of. Some folks fear anything different or new. And even more believe everything they read on the net. That is, if they agree with it..... :wink:

Anonymous-0 · Jul 17, 2011

I would not be worried about the gas. As far as the wires, they are to close to the manifold

Unleaded gas in old engines

jason, NW Ontario

Member

Dean

Well-known Member

S.Crum

Well-known Member

onefarmer

Well-known Member

skip33652

Member

IaGary

Well-known Member

buickanddeere

Well-known Member

gene bender

Well-known Member

Billy NY

Well-known Member

John Harmon

Member

bob15

Member

Anonymous-0

Well-known Member

Will Herring

Well-known Member

Spook

Well-known Member

Anonymous-0

Well-known Member

Similar threads