Leaded Gasoline

My WC, as long as we have had it running, has a slight miss. I changed the spark plugs and the magneto is untouched, other than cleaning the points. You would know its not the timing because it has to be in time to crank start as easily as it does. Anyway while sitting around a thought crossed my mind. Should I get a lead additive for the fuel since all the gas in 1937 was leaded? I did put a bottle of carb cleaner in it that seemed to help some but the carb is new so I know its good and clean. Should I get this additive? Will it help stop this miss?

Gas wasn't necessarily leaded in 1938, that was a war time innovation. Lead additive will add to the problems by fouling spark plugs. Be sure to use something for plugs other than Champion plugs because the ceramic in Champion plugs doesn't clean after a smoky start.

Easy cranking says retarded spark which is normal for the magneto. Be sure its advance for running because retarded spark is not what it takes to make power.

Be sure to have metal, not carbon plug wires that make good connections at both ends. Carbon wires break and also reduce the spark intensity and are not good for the magneto ignition, or any tractor ignition.

Then have you tune that new carburetor? Only the latest versions of carburetors come factory tuned, all others need tuning to match the engine and the fuel. The settings in the book are just close enough to get it to run so you can finesse it later.

Gerald J.

If its been run several years with the oem exhaust seats on unleaded fuel . Its quiet possible that the seats are beat out and it should have a noticeable popping sound in the exhaust .

CJohnS MI wrote: mlpankey wrote: If its been run several years with the oem exhaust seats on unleaded fuel . Its quiet possible that the seats are beat out and it should have a noticeable popping sound in the exhaust .

  So you dont think lead was used in fuel to act as a buffer and the design of harden seats is a fleecing of the general  public ?

DaveKamp wrote: Hi Jeremy- "Should I get a lead additive for the fuel since all the gas in 1937 was leaded?" This is a misnomer at least, and much closer to an outright falsehood. From a farm and road fuel industry standpoint, practically NONE of the gasoline in 1937 had Tetraethyl Lead additives.  Considering using it to 'help protect' valve seats in ANY domestic engine manufactured prior to the end of WW2 is pointless- with exception of very few manufacturers, all industrial and agricultural engines were low compression, with hardened valve seats, intended to run well on a variety of different fuels (not only liquid, but also gaseous NG and LP with no long-term wear effects. Pull out a valve seat, break it, and apply a Rockwell hardness tester, and you'll find that the original seats are RC40 or harder, and the valve faces are right up there.  The '37 WC I just pulled apart (and I believe it to be the original head) tested RC51, so WAY harder than required for non-TEL use. After TEL was heavily advertised into the environment (like California/EPA did with MBTE in the early '80s'), manufacturers of non-industrial gasoline engines (car manufacturers) went to softer iron seat materials (cost savings) because they COULD. http://en.wikipedia.org/wiki/Tetraethyllead Now, this in mind, that doesn't discount that there could be SOME OTHER failure.  If it's missing on ONE cylinder, then you don't have a fuel-type problem, you have a ONE_CYLINDER type problem...  could be: That cylinder has a sparkplug problem (switch plugs around, see if it follows) That cylinder has a gasket or ring-type problem... That magneto has some sort of problem with THAT plug tower That cylinder may have a valve with insufficient lash (pop the lid and check it, when in doubt, give it a little more slack) That cylinder may have a lazy valve spring or cruddy valve guide That cylinder may have a CRACKED or loose valve seat That INTAKE or Exhaust port may be making a poor seal, and once running, thermal expansion exacerbates the situation, causing it to run lean and miss. I'd say, investigate these other possibilities instead, and you'll probably find the problem.

Can I get an Amen?

AMEN!

DaveKamp wrote: Hi Jeremy- "Should I get a lead additive for the fuel since all the gas in 1937 was leaded?" This is a misnomer at least, and much closer to an outright falsehood. From a farm and road fuel industry standpoint, practically NONE of the gasoline in 1937 had Tetraethyl Lead additives.  Considering using it to 'help protect' valve seats in ANY domestic engine manufactured prior to the end of WW2 is pointless- with exception of very few manufacturers, all industrial and agricultural engines were low compression, with hardened valve seats, intended to run well on a variety of different fuels (not only liquid, but also gaseous NG and LP with no long-term wear effects. Pull out a valve seat, break it, and apply a Rockwell hardness tester, and you'll find that the original seats are RC40 or harder, and the valve faces are right up there.  The '37 WC I just pulled apart (and I believe it to be the original head) tested RC51, so WAY harder than required for non-TEL use. After TEL was heavily advertised into the environment (like California/EPA did with MBTE in the early '80s'), manufacturers of non-industrial gasoline engines (car manufacturers) went to softer iron seat materials (cost savings) because they COULD. http://en.wikipedia.org/wiki/Tetraethyllead Now, this in mind, that doesn't discount that there could be SOME OTHER failure.  If it's missing on ONE cylinder, then you don't have a fuel-type problem, you have a ONE_CYLINDER type problem...  could be: That cylinder has a sparkplug problem (switch plugs around, see if it follows) That cylinder has a gasket or ring-type problem... That magneto has some sort of problem with THAT plug tower That cylinder may have a valve with insufficient lash (pop the lid and check it, when in doubt, give it a little more slack) That cylinder may have a lazy valve spring or cruddy valve guide That cylinder may have a CRACKED or loose valve seat That INTAKE or Exhaust port may be making a poor seal, and once running, thermal expansion exacerbates the situation, causing it to run lean and miss. I'd say, investigate these other possibilities instead, and you'll probably find the problem.

Find a spot that gets nice and dark at night, start the engine and watch the sparkplugs and wires for arcing. If there is no arcing, speed the engine up to 1/2 throttle and check again.

wkpoor, I was just about to suggest just that but the Pastor and his wife pulled into the drive for a quick visit and 2 1/2 hours later they just left. We had a real good visit and he even spotted my WD45 and called it by it's model and could distinguish between that and a WD. I think I'm gonna join that church!

I've found darned few that needed much more than a light grinding of both the seat and the valve... most times, 20-seconds with a lapping cup takes care of it... but keep in mind that an engine with 20 years of service doesn't necessarily identify it to a particular decade.  Most Industrial and agricultural engines built between the mid '20's and late '50's had some pretty well made seats and valves.

Knocking out seats, guides, installing new seats, guides, and valves, and lapping 'em to proper fitment is ALWAYS a reasonable thing to do, but I've not yet found an AC engine where the seats were eroded or hammered into the head, and the valves have all been exceptional... matter of fact, my valve grinder has NEVER had the opportunity to recut an Allis valve.

These engines, in stock form, run a very low BMEP, very conservative timing, and low CR, so burning up valves and seats really gets left to having improper lash.

I think Jeremy's problem will probably turn out to either be electrical or plug related, a vacuum leak at the intake or exhaust, a valve that needs a smidgen more clearance, or a head gasket weeping coolant into the chamber... but clearly the suggestion of using lead additives to resolve a one-cylinder warm-engine miss is logically not addressing the real problem.

where at on the manifold, is your manifold leaking/cracked/warped?  Or do you mean the muffler.  Either way it do to fuel burning outside of the combustion chamber which could be an ignition/timing problem or even a carb problem.  Lots of what ifs without seeing it. 

I have farmed a lot of hours with unleaded gas. Plowing, fitting ground, planting and harvesting and have not had a gas related problem.  Blaming your problems on unleaded gas is a myth based on other people unfounded opinions. When they started to dump unleaded gas in my under ground tank at the farm the gas man told me to add a quart of diesel to each tank to keep from having valve problems.  I did for a while and then didn't bother. No valve problems ever came up.

You MAY have a slight crack or hole in the manifold that is allowing a little 'pass-through' when the manifold gets at just-the-right temperature.  A close visual MAY indicate an internal crack... if you see one, or see a situation where the gasket surfaces aren't making good contact, change the manifold.

Pank, re-read his first post:  "since all the fuel in 1937 was leaded"

This is NOT true.  Very little, in fact, was.  Yes, GM/Kettering Labs ("ETHYL") wanted everyone to think otherwise.  Matter of fact, they tried REALLY HARD to downplay the "LEAD" concept by using the ETHYL trade-name... (tetraethyl lead).  Conspiracy?  Of course, but that is pronounced in a business-environment as "MARKETING".

Next, re-read what he's ASKING, and look at the SYMPTOM:  Miss on one cylinder.

Do you REALLY think that including additives in fuel is going to solve a problem?

No.  

He may have a cracked valve seat, or may have one needing lapping, but that wasn't his question-  it was "should I add lead".  Answer is NO.  It appears, however, that it stops missing under load... so this isn't a fuel-quality symptom.  Furthermore, if he was having a recessed  or damaged valve seat issue, it certainly wouldn't clear up under a change of load... it would burn up, and get worse.

Before condemning the valves and seats, do proper troubleshooting via empirical testing.  Here's some simple hints:

--If one suspects a compression problem, 10 minutes with a leakdown tester will prove it out.

--If one suspects a leaky manifold, wave an unlit propane torch around the manifold gaskets and castings.  If the engine speed changes, you have a vacuum leak.  If the torch lights, you have an exhaust leak.  Fix it.

--Prove that your ignition system is operating properly.  If you don't have a viscious blue spark at the plug when the impulser clacks, take the mag to someone who's really good at mags, to be cleaned out, lubricated, and tested.  It's certainly worth the effort.

--Prove that the head gasket isn't leaking... look for bubbles in the radiator, look for bubbles and weeping around the head, look for signs of coolant in the oil.

--Prove that the engine isn't suffering from a very worn bore... smoke out the stack, or raining oil is substantial indicator.

--Prove that the plugs aren't fouling... once it misses, kill the engine, pull the plugs, and take a look.  Look up spark-plug color examples, and see if you have appropriate color on the electrodes and insulator.  Make sure you have proper heat-range for the application.  IF ONE plug appears to be having problems, swap plugs to different cylinders.  If problem follows plug, replace the plug... if problem doesn't, problem isn't the plug... could be wires, caps, magneto, or fuel/air mixture.

--If the miss clears up when you pull the choke out a smidgen, pull, dismantle, soak, and clean out the carb, reassemble with new gaskets.  While you're at it, yank the fuel tank and fuel line, clean 'me both out good, and refill it with fresh gasoline.

Did you TUNE that new carburetor? Carburetors of that vintage were NOT factory tuned, they have to be adjusted on the tractor and with the fuel you plan to use. There is no compensation for different fuel either. E10 tunes differently than straight unleaded.

Gerald J.