After spending the winter rebuilding the entire drive line of my 1926 Model T Ford coupe and re-torquing the head bolts I made the final test run and Seabiscuit ran great! How great you may ask, will as I told the officer "I didn't realize how fast I was going, I only had the throttle a third of the way down"!
Looks like it runs really well. John
Thanks John, the T is really running GREAT! Yesterday I installed a dip stick so I can check my oil every day before starting without crawling under the T. After I went for a short 10 mile run, that I call the acid test. It involves coming home via Groham Pond Road which has an 8% grade, that Seabiscuit came up in high gear!
Great job Warren, but curious to why you have the spark lever so far advanced ??
Thanks George, I always drive with the spark at full advance. Sometimes in the past I have retarded the spark a little going up hill, but since the rebuild I have not felt the need to do this when going up steep (8%) grades.
This is a 2 mile up hill grade here in Dunbarton, some of it is an 8% incline
When you set the spark lever try running a fast idle about the engine speed you would be going 35 mph. Move the spark lever down and you will find a spot where the engine runs fastest and smoothest. When you advance beyond that point it begins to lope. The spot where it runs smoothest is called the "sweet spot" That's where you should run it for most driving. If the engine is running more slowly such as in a driveway, dirt road, or pulling a hill, the sweet spot will be more retarded. It is not good for the engine to run it more advanced or more retarded than necessary. In fact it could actually cause damage. To far advanced could even try to run the engine backward but because of the momentum it will pass top dead center and continue to turn forward. That point where it is just before top dead center will cause most knocks sound worse. It could even cause a knock to develop because of the strain on the parts. I once had a car which had a distributor and I over advanced it, thinking it would run better. The car developed pre-ignition and then started misfiring on one cylinder. Upon pulling the spark plugs, I found the center electrode missing. It had completely burnt off. The reason for advancing the spark is because as the engine speed increases, the time it takes to ignite the fuel does not increase and so by the time it is ignited, it is already just past top dead center. Advancing more than that will cause the problems. Also running to far retarded will cause the combusting fuel to pass the exhaust valves causing them to burn or warp. It will also overheat the exhaust system and even cause backfiring in the exhaust. It causes the engine to overheat. So learn to find the "sweet spot" and run in that area.
Hmm, anyone have thoughts on running over-advanced causing crankshaft breakage???
Norm, here is the original video without the music. I believe the clicking sound that the camera is picking up are the coils working.
Just because his spark lever is all the way down it doesn't necessarily mean he's too far advanced. It all depends how his linkage is bent and adjusted. However, I will say that if the proper advance is at that setting, then he's got to be way too retarded with the lever all the way up.
If you start out in low with the spark lever half way down and leave it that way until you pick up enough speed in high you will have less tendency to over rev in low.
A lot of T drivers pull the advance lever all the way down as soon as the engine is started.
I start it on battery with it fully retarded and then slowly advance it until the engine is running at what sounds like the best rpms with the fuel nearly closed.