Have been taking my T for ride these days but interestingly even after very short rides the Manifold becomes "Red Hot" which scares me a lot.
Wonder what the issue could be? The spark lever is on 5th level and the throttle is on between 6th and 7th levels.
Running carb too lean. Give it more fuel with mixture rod.
Just because the lever is at a certain point on the quadrant does not mean the timing is correct.
Generally a Red hot exhaust manifold is incorrect timing or a lean fuel mixture.
What Dallas and Michael said. Dave
Here's how it was explained to me:
By the time the piston begins its up-stroke after the Power stroke, the fuel should be more or less completely burned. If not, you get FIRE going out the exhaust valve. This will make the manifold turn red-hot, and eventually burn the valve.
The fix for this is simple -- just advance the timing. In other words, pull the spark lever down. This will make the spark plug begin the burn process sooner, so it will finish before the up-stroke begins.
I've always found that as you pull the lever down, you'll find a "sweet spot" where the engine seems to run better. That spot should change with your speed. So, proper operation of a T means working both those levers.
I don't know exactly why too lean a mixture will have the same effect, but Dallas is certainly not the first person who has said so.
Many thanks for all the information. What should be the Ideal Fuel mixture? I mean how many turns should I make on the Rod for optimum mix. How much advance should I move the spark lever to?
congratulations to you and your crew of helpers to have gotten this far, with the troubles you've encountered. Very gratifying to see that you're at the point of driving...
Thanks Scott. Just paranoid that nothing else goes wrong now. Dying to go for a long drive.
Fuel lean = oxygen rich. More oxygen = more heat. When I light an oxy-acetylene torch, the acetylene just sputters a!ong. When I turn on the oxygen, now I can cut steel. (Now if someone can explain why this is so....)
SID, When you pull down on the timing lever with the engine running, the engine will speed up some and not sound like its is pulling a hill. Having the carburetor too lean,adjustment turned clock wise, the engine will start to cough, and too rich, adjustment turned anti-clockwise, the engine will blubber. It sounds like most of your adjustment should be the timing. Don't be afraid to adjust it. Up for start and mid way for idle and low speeds to all the way down at high speed. If this don't work,you may need to check the rod that attaches to the timer, it may be bent.
SID, When you pull down on the timing lever with the engine running, the engine will speed up some and not sound like its is pulling a hill. Having the carburetor too lean,adjustment turned clock wise, the engine will start to cough, and too rich, adjustment turned anti-clockwise, the engine will blubber. It sounds like most of your adjustment should be the timing. Don't be afraid to adjust it. Up for start and mid way for idle and low speeds to all the way down at high speed. If this don't work,you may need to check the operation of the timing adjust. The rod that attaches to the timer may be bent.
to your question on mixture: If your carb is rebuilt/working correctly, you will find that after starting and fully warmed up, you should be able to enrich the mixture (turn mixture to left or counter-clockwise) and the engine will start to blubber and perhaps give off a little black smoke out the tailpipe...note the position of the adjustment at this point...then lean it out (mixture right, or clockwise)...engine will speed up a little, smooth out and as you continue to turn the mixture, it will start to blubber again and try to die...note this position, too. Now, place mixture exactly between these two settings...this is a general location for good running.
Note: while wrong mixture or spark setting will cause a red hot exhaust, an incorrect spark setting (too far retarded) will have the most effect good/bad on exhaust heat.
Ensure your timer rod is bent/adjusted such that when fully retarded, the spark occurs after top dead center, but not TOO far past. I believe the factory setting is about 15 degrees past TDC.
With that setting correct at full retard for starting, you should have correct range of spark when driving.
How to know where to put spark when driving: Until you're used to it, the easiest way is this...get under way, get into top gear on level ground...set throttle at about 1/3 throttle and let car settle to speed...pull spark rod down and car will pick up speed...note at what position the spark lever is at when car CEASES to accellerate...this is close to optimal setting. Correct spark setting is dependent on ENGINE speed not road speed...thus, there is also a correct setting for idle, low gear, high gear...all dependent on engine speed. For your purpose right now, after you start the car, pull lever down until engine speed picks up (you may even have to close the throttle a bit to keep engine speed down). This general spark location is OK for low speed starting out as you only spend a few moments in low before you shift to high. Now, if you're pulling a long hill in low, you definitely MUST pay attention to spark lever and optimize it or you will get very hot very quickly.
Go with what others have said. You should be adjusting your spark lever and fuel mixture with every change in engine condition, from pulling a hill to idling. You will find the sweet spots for all the conditions. This is all done automatically by the engine management computer in a modern car, but you have to be the computer in a T Model.
There is usually a knee in the spark advance, meaning that as you advance the spark the engine will run better to a point where further advance makes no difference. That is the knee or sweet spot. Same goes for the mixture control, but run it slightly rich because the engine will run cooler.
Gasoline will cool when it evaporates, just like sweat on you body. So running slightly rich will make the engine run cooler. The mixture also controls how fast the fuel/air burns, so a leaner mixture will have the burning still taking place when the exhaust valve opens leading to burning taking place in the exhaust manifold and a hotter manifold.
Sid, there's no set number of turns for adjusting all Model T carburetors. The one I'm currently using prefers to be open only ½ to ¾ turn. Others demand a full turn or more. Many also need different settings for idling or driving.
Here's how to adjust. With the engine running, turn the adjustment to where the engine runs best. Open the valve to where the engine starts to stumble (fail/sputter). Turn it the other direction until the same happens again. Halfway between the stumbles is the best spot. Do this with the car idling, then again while driving to see if this particular carburetor requires different settings.
Ignition timing also may need different settings on different cars. First, make sure the timer is set properly: http://dauntlessgeezer.com/DG97.html.
Best practice when driving is to pull the lever down to where the engine runs best. On my car this is usually far down on the quadrant, almost to the bottom. When I start to hear spark knock (detonation) I raise the lever until the noise stops. Some people call it pinging, but I don't because it sounds more like a knock. It usually occurs during acceleration or climbing up a hill.
Steve's advice is sound. Just remember that you are trying to adjust two systems (fuel and ignition) that, while separate systems, interact with each other. It may be necessary to fiddle with one then the other a couple of times before you get it to it's optimum.
Give the spark lever 80% advance and see how well it goes. I find I can give mine nearly full advance under most conditions.
I agree with what was posted above. The proper setting of the spark starts with the position of the timer when the spark lever is all the way up. You want the spark to come just after the piston starts down after top dead center on the compression stroke. You should also have tight linkage. If it is sloppy, you might move the lever down without moving the timer. So start with the linkage and the rod adjustment to get the spark at full retard in proper position, then pull it down a bit and the timer should start turning right when facing it from the front of the car.
As a side note, a red hot exhaust manifold is also the cause of warped manifold.
Then too, if a cylinder misfires and dumps the gas mixture in the exhaust manifold, it will be lit with the overlap from the cylinder that fires next.
Steve I would not think the spark lever would be in the almost fully down position normally.(level road driving). I saw you do this in a video a while back and was quite surprised because I don't think it's the correct/normal position for level road driving. Are you sure about the linkage and connecting parts?
After you try adjusting it as directed and the manifold still turns red, you may have a leak in one of the two gaskets ,or rings and glands, where the intake manifold is clamped onto the engine. This causes it to run lean and will cause the exhaust manifold to turn red quickly. It may be as simple as just tightening your manifold clamps, or replacing the gaskets.
An easy way to check for a leak at the two locations is to squirt a small amount of light oil or carburetor cleaner around them while the engine is running. If the engine speeds up or runs smoother, you found the leak.
Sounds like lean condition on carb or timing as stated above.
I have this accessory carb adjuster on the ‘23. Very handy.
Thanks all. Very useful. Quick question, to adjust the timer do I necessarily need to remove the Radiator or can the Timer be adjusted without the removing the Radiator?
Mine is a 1915 Runabout.
Noticed there is a bit of play in my spark lever rod as it does not go all the up. Is it ok or do I need to bent the rod a bit?
Merry Christmas Sid, Just try running it more advanced first. You don't need to take the radiator of to adjust the rod if needed.
It can be adjusted with radiator in place. Adjust for correct safe retard when starting, using lever at column all the way "up".
Once running you will have to pull the lever "down" more than normal, since the first movement of the lever will not result in movement of the timer...for example, at 30 Miles per hour on the flat, my spark lever (with NO slop) points to about "8 o'clock". A lever with slop may have to be pulled down to your lap.
I think you've just found why your manifold runs so hot...with slop, the engine has been running far too retarded when at speed.
Sid, the picture here http://dauntlessgeezer.com/DG97.html is on my 1915, looking under the radiator. You can easily see the pin.
Thanks Steve. Can the Timer be adjusted without removing the Radiator?
Asked and answered twice already
Sure. Just follow the steps in the link.
Or, if none of the above works to reduce the red hot, it may be that the valves are already warped or burned.
Like Scott, I'm glad to hear you're up and running again Sid.
I don't think Sid is running the Mumbai 500 quite yet. :-)
Sorry to bump, didn't realize I'm behind again.