Well, not really but I don't doubt it could happen.
I have a 25 coupe that is giving me fits with no power or speed.
Engine was rebuilt by a reputable builder who has done two engines for me before. Engine and transmission are quiet and smooth. Compression on all cylinders is between 55 and 60. I have a 7.5 degree advanced cam. The high head was shaved .100". I use a distributor, NH carb, Autolite plugs, new radiator, rebuilt NH Potter carb, and new gas tank. Car uses 6 volts. All ignition parts are designated 6 volts.
The problem is a severe lack of speed and power as compared to the 24 touring car with the exact same set up. The car starts easy, runs well with no missing or hesitation. Car can be pushed by hand in neutral. It will start with starter or by hand with no big problems. The car does not smoke and when the plugs are removed, they are clean. The new plug wires have been soldered for good connection and each plug has the same effect when shorted out to the head. Fuel line is clean and the carb has been removed and inspected with no obvious problems. Exhaust pipe is clean and the muffler seems to be open and not clogged. I have replaced the copper gaskets at the manifold.
I am kind of running out of things to check, repair or replace. I've got to be missing something. And suggestions would be welcomed.
How about ignition timing? If you are running a non stock cam or if there is something going on with the coil or condenser, it would have the same effect as you describe. I had a problem with my dad's 23 TT, it would try to start but wouldn't quite catch and run. It has a Texas T distributor. I happened to be looking at the engine when he adjusted the spark and I noticed the rod and lever move but the distributor didn't. The bolt that clamps the arm on the distributor housing had loosened up and allowed the distributor to rotate to who knows where. The thing was way out of time. He said it had been hard to start and had been lacking it's usual power for a while. Just because we run distributors doesn't mean they are bullet proof and don't require occasional attention.
Does your distributor auto advance? If not, when you move the spark lever , do you get a noticeable difference in how the engine runs. Can you physically see the distributor turn when the spark lever is moved. Acts like it is stuck totally retarded.
The commutator rod is connected and doing its job.
Running down the road, the car just stops accelerating runs out of power with throttle all the way down. Approaching a hill or running on the flat it slows for what seems to be the lack of power. Still no misses or anything that would seem out of whack.
Tom, did you check your carb linkage to make sure it is opening all of the way? Just a thought. Dave
Dave, I did and it was not. Got it adjusted as it should be and went for a ride. Not much help.
Whatever this is, it's effect is big. It's gonna be something dumb when I (we) get it figured out.
The next move is to look at valves to see how they are opening and operating.
What is different is that when sitting still, when the engine is revved up, it just does not get with it like the other T's I drive do.
Did you check the timing to see if the spark is happening at the right place? It sounds like the timing is way retarded from stock.
Silly question....what gears (ratio) is in the rear end?
Don't think it would make a difference because if a low speed you should power up the hills and high would give you speed on the level.
Please let us know when you figure it out.
When you say it has now power, are you saying that it consistently has no power all around, or does it start loosing power when you try to get up to speed?
If it just doesn't seem to have any power at all (which is what it sounds like you're saying), I'd still suspect ignition. It could be that you're not getting enough advance at the distributor, even though the linkage does appear to be working. If you're not running a Texas T distributor, then it will probably have a reversing linkage. I've seen several of them where the linkage is so sloppy that you get maybe half the advance that you should.
In addition, I'd say perform a leakdown test. If you can't do that, then just check the valve clearances and make sure that they are set to about 0.010". If the valves aren't seating all the way, it can still give you good compression readings, but will leak combustion gasses when running.
I think that leaking valves are a likely candidate because when I got my T, it had the same symptoms you are having now. It would start easily and just purr. No signs of trouble from just listening to it. But if you tried to drive it, it just had no power and could hardly get out of its own way. A new set of valves, a good lapping, and correct clearances made all the difference!
Tom do you have a 10 tooth pinion in your coupe. I have a stock 25 coupe that runs great with the 10 tooth. The heavier coupes and sedans came with the 4 to 1 ratio.
Standard rear end. But the lack of power all the time is the issue. And it has kind of been this way since the rebuild. I have had multiple coils and rotors and points but Never changed the condenser. When I installed the new advanced cam gear several years ago, I checked to make certain of the timing and it was correct. The one item I have not done was to remove the head and valve cover and check all that out. I even replaced the intake manifold thinking there might be an issue there. I am beginning to wonder if the valve guides are tight causing valve lag.
This car does not get driven much and with cold weather coming and a tour in November to go to, an enclosed car would be fun. But not if it does not run to suit me.
Keep any ideas you may have coming.
I think Royce is on the right track, sounds like you may be a tooth off on the dizzy, easy to do with those things. KGB
Tom- a remote possibility- while on a tour in Corydon a few years back, my hack demonstrated the same symptoms. On level roads she ran fine (sometimes), but come to a slight grade I had to shift to Ruckstell, and sometimes even go to Ford low. It never missed, spit, or sputtered. Just no power. Unusual for this particular Model T.
When I got home I found the problem. The cam nut had loosened. In turn, the 2 pins on the cam had wallowed the holes in the cam & the timing gear. This allowed the timing gear to "sometimes run advanced, sometimes run retarded".
I replaced the cam & timing gear and she went back to normal.
Bill, I will look at that. I have had this engine in two cars, both with different carbs, manifolds and distributors. Same symptoms. I put it in this car and had others rebuilt for other cars. Now they all run good and this one still has the same symptoms. Sure seems to be specific to the short block but damned if I can find it. This is a nice bodied car and needs to be played with.
Tom- you are too old for that stuff!
Have you tried a vacuum check on the intake manifold. Could be a block problem.---Len
Bite the bullet. It has wrong timing somewhere...
It is either valve timing or ignition timing.
It seems you would have found ignition timing by now so it is valve timing. Pull the radiator, pull the front timing cover and check the "Ford" is opposite the dot. I have seen other marks on the cam gear on both Model T and VW bugs. With the bug, it resulted in a major effort.
Just my two cents.
How could you tell the horse was Amish?
Probably by the haircut.
I'm with Tony, valve timing is one tooth off. I did this myself some years ago. It ran fine, sounded good in the shop but just didn't have any power on the road.
I will begin taking it apart today. Sure seems like when I put the advanced gear in that I would have not done it wrong but who knows. In this instance the advanced gear did not help.
Thanks to all for the help. When I figure it out I will let you know.
As far as the Amish part goes, if I had said a horse and buggy, the visual just would not have been the same. And I was just in Amish country last week and it seemed appropriate.
Tom, I know I'm not as experienced as others on the forum but I would think a simple check of the gas line and tank would also be in order. When you run at idle and lower less demanding speed you may have enough gas to run smoothly. However, when you demand more power, the gas flow may be restricted enough to not generate the power. Just thinking.
Good idea. I have already gone through the fuel system from tank to carb to intake. Have found several minor things and when set up properly had no effect. Seems like if it ran out of fuel that it would sputter, etc. it just gets to a speed and no more. And during all of this time, it runs smooth.
If I had any hair, I would pull it out.
I have a 40 hp Chalmers that could not get out of it's own way for some reason. I just assumed that was the way they were as the car started easily and ran smoothly and, after all, I am used to Model T's. I had a friend of mine drive it and he was shocked at how little power it had compared to the other 40hp cars he has driven. Turns out someone at some point in the cars past installed the cam gear one tooth off. That corrected, the car now runs like the wind! It's amazing what a difference one little tooth can make!
Got everything opened up. Pistons are clean, head gasket great, Timing gears are in time. Valve lash on all valves is .012". Valves show no sign of hangings up and all valve springs are intact and doing their job. No end play in the cam and the nylon gear looks great with no wear. The combustion chambers in all 4 cylinders of the head are clean with only marginal carbon, really not enough to require being scraped.
I guess it is possible that the cam is ground wrong but not likely. According to the book, everything that could cause lack of power is checking out to be OK.
Any other thoughts or suggestions will be appreciated. I hate to put it back together finding nothing out of kilter and wind up with the same poor performance.
When you put it back together will it be with a standard gear or the advanced gear?
I had planned on using the advanced. I have that in two other cars and it works well with those.
I don't know when I am going to put it back together. I sure would like to find out what is wrong first.
Have you checked valve spring pressure for weak springs? Les Sumner
Are you absolutely sure the large timing gear is machined correctly ? I had bought a new timing gear several years ago and I found the timing mark was on the wrong tooth. Les Sumner
Get the tool for setting valves according to piston position, we had an engine doing the same thing. Valve timing was off even though everything lined up on the timing gears. We got the tool and things were running late, a whole tooth late. Reset the timing and the engine came alive.
I had the same problem with the aluminum gear that came with the rebuild. I still believe it is in the short block, maybe a bad cam? All the springs are new, along with valves.
Keep ideas coming. I am ordering a new cam this morning in hopes that the one in there now is not correct.
I appreciate everyone's input on my problem. After looking at all of the conditions, I have ordered a reground cam from Chaffin's and it should be here hopefully the end of the week. If all goes well, I will get it in over the weekend and let everyone know the end result. This is kind of the final step and hopefully the step that will get this car in good shape.
Again, thanks for everyone who weighed in.
Before you change anything on the short block you can compare the valve timing to Fordīs specifications - if everything is about 15 degrees wrong, all you have to do is move the timing gear one tooth.
(From the Tulsa Model T club's cam project web site: http://mtfctulsa.com/Cams/design_stock.htm )
Because of being out of town, I finally got the new cam in the car and it runs pretty well. I did not get to drive it as it had a flat tire and I am out of town again.
When taking everything apart, I found nothing out of sorts. I put a Chaffin reground cam in, with the .270 lift. Set the valves at the recommended .015". The car starts easy and seems to rev up better than before. There is a big lift difference in the new cam verses the old one.
Once I get back home, I will get it on the road and see how it performs. The new tube and flap will fix the flat. The tube had a cut in it because whoever put the new tubes and tires on did not use a flap on the slit rim. I can only imagine that the other 3 (4) are the same way.
Thanks to all who commented on my problem. I only hope this fixes the problem. The tour we will go on in November is not that far away. It sure would be nice to drive a closed car.
Tom, my 23 Centerdoor was running good. About 10 miles from home it started getting lazy. I found out that the battery was very low and when I hooked up the charger to it the old car came back to life. I'm just throwing that out as I didn't see or missed any mention of battery above.