My '21 Model T has been overheating. I pulled the head and flushed the block and replaced the head gasket. Replaced the water pump and flushed the radiator. Alas the car still overheats when idling or pulling a hill, it has a VW distributor and Coil i'm looking for advice on adjusting the timing as that seems to be the only remaining culprit. The car does run a little rough.
Reading the list of what you've done so far, I'd say timing is not the only remaining culprit.
See the seventh paragraph here: http://dauntlessgeezer.com/DG96.html.
Make sure the tubes are still attached to the fins.
Not sure about VW distributors. I assume they have an automatic advance? I'd adjust it to where with it fully retarded, it fires JUST after top dead center. Assuming it has an automatic advance, you might want to ensure the advance mechanism is working properly.
However, my money is on a bad radiator. the fact it has a water pump is a good indicator someone was having overheating problems in the past. Otherwise, few people put one on, as a T with a good radiator cools just fine without a pump.
Re-reading my post, I began to think about how far advanced your advance mechanism will advance your spark. My original suggestion was meant to give you maximum advance without becoming unsafe to crank. It MAY give you TOO much advance resulting in some detonation, but you could always back off that initial adjustment if it does.
Bert...got your email and sent you a response. You may have already gotten it.
It could be a lot of different things besides the timing and radiator. It may be a combination of things. Sticking valves, fan blades too flat (you only need a fan when idling or running very slow as in a parade), leaking manifold gaskets, carburetor, spark plugs, new engine that is still tight...all things that make a Model T not run at its peak. One other thing on the radiator; has the core been painted with some type of heavy paint?
Is the radiator an original Ford radiator that still looks decent, and older recore, honeycomb or etc?
You mentioned you replaced the water pump. Did you replace it with a better or new one?
If it had a water pump when you got the car or if you added one later it sounds like it had an overheating issue and adding the water pump was a supposed fix.
Radiators do wear out. The fins eventually get loose from the tubes and there goes your cooling efficiency. Just because a radiator 'looks' good doesn't make it so.
If its an original radiator that's a definite suspect of your problem.
Maybe you are leaning the carb to much
A rad flush doesn't accomplish much. A vinegar treatment does a lot more!!!
Is this a new problem. Some history can help us help you
Robert - Even while your "T" is overheated, if the lower radiator outlet and hose that attaches to water pump is too hot to touch, that would be a good indication that your radiator is not cooling sufficiently. I' replace the water pump with the factory stock cast iron water pipe outlet and proper hose from there to lower radiator outlet and see what happens then. You might find that the radiator cools the engine BETTER WITHOUT the water pump. And if it the overheating IS caused by inefficient radiator, you'll end up replacing (or re-coring) that radiator anyway, at which time I'd certainly replace it WITHOUT the water pump, in which case, you'll need that new cast iron water pipe outlet and lower hose anyway. FWIW,......harold
The radiator was taken to a look shop and flushed using an air/water tool. How can I tell where is the best spot to look to make sure my fins are connected ? The radiator is stamped 1926 and as best I can tell it's the round tube type. The head was removed and the water passages soaked with an acid used in tractor engines and then flushed. A new silicone style hey gasket was installed and the head replaced. When I got the car it had a water pump on it and I replaced it with a new water pump. The spark Rod rolls the distributor when adjusted. The car also has a fan and has good airflow through the radiator. The car runs well but seems to be lacking power.
Lacking power in combination with overheating points towards a too retarded timing. Check where #1 piston is when the spark plug is firing and you have the spark lever fully up. The crank pin in the front end of the crank shaft is horisontal when the piston is at top dead center.
After the car has run for a while and is hot, take a temperature measurement at the top of the radiator tank and at the bottom return pipe. If you don't see a drop of at least 20 degrees, I'd say you've got a bad radiator. It doesn't matter what your timing issue may or may not be, the radiator should still show a temperature drop from inlet to outlet if it's in good condition.
Robert - I know what you mean! I think it's almost impossible to tell by looking at the radiator. I just know that just 80 or 90 years, and all those years of vibration cause a radiator to be inefficient, and I'm not sure that even a radiator shop can tell by visual inspection. You just can't hardly "SEE" that all of the thousands of little "contact points" that are no longer tight, and therefore, do not transfer heat like they should, and so many of those loose "contact points" add up! And that's when many "T" folks decided to add a water pump, which actually "DID" help some,.....for awhile. It's a difficult situation, and the main reason why sometimes, the best choice is to quit fighting it and just buy a new radiator. It's just too bad that they are so darn expensive,......harold
Robert - I just re-read your last post, and I missed something the first time I read it.
You won't like to hear this, but you mentioned that your radiator is the "round tube" type. I have learned via this forum, that "purists" prefer the "round tube" radiators, as they are more original. However, I guess it is a known fact that the flat tube type radiators are a much better choice for a "driver" grade of Model "T", simply because the flat tube design cools much better because of the additional surface area with the flat tubes. I'm sure that is no doubt at least part of your overheating problem. Again,.....FWIW,......harold
This is a long shot but no one has mentioned the possibility of the baffle in the top tank may have fallen and blocking the tubes. This happened to a radiator that I had that was removed, taken to radiator shop to be cleaned out. It would overheat in 15 minutes. I took it off and heard a rattle and found the problem.
Robert, I have a texas t parts veedub dizzy on my T.
My timing lever hardly reaches "mid point" of the quadrant. How's yours?
Assuming starting timing is right at (or just after) TDC?