MTFCA Forum

Hello I have access to some model T engine parts. What is a low head ? how do you ID them There is a pile of crank shafts indoors. How do identify what year they are?

Thanks Mike

Michael, although there were some small changes in the combustion chamber volume over the years, the term low head and high head usually refer to the exterior height. High heads having more water jacket volume for better cooling. You should be able to eyeball it if you have a high head and a low head side by side.

Regarding cranks, generally speaking, all cranks are interchangeable. Many have a preference for the later EE crankshafts, they are marked EE somewhere on the forging.

for visual difference: http://www.mtfca.com/discus/messages/50 ... 1441864460

Low heads are approx. 2" in height - highs are approx. 2 & 3/4" in height. Crankshaft profiles distinguish early from late - early have a "diamond" crank throw & late have "parallel" throws - late style can have AA or EE and I have EE cranks stamped into the pulley end.

Thanks The pictures shows the real difference. Low head water jacket much taller. I will look at the cranks and take some pictures.


Thanks again Mike

If I remember, the combustion chambers on the heads aren’t exactly alike in appearance along with the different height in the heads. Those are the 2 main differences.

The low heads with which I am familiar have a distinctive ridge around the spark plug holes. On the high heads there is no ridge. The spark plug hole looks just as though the hole was drilled and tapped.

Allan from down under.

Items such as these heads were cast in numbers at one time, depending up[ the size of the object. Most such casting patterns had a letter or number for each item on the match plate. In that way if a casting showed defects, they knew which one on the match plate was defective. I assume Model T Head were cast in grey iron and then heat treated.

Darel

Correct on the heads made from cast iron.

Weren’t heat treated as my SawsAll wouldn’t have been able to quickly section, like cutting through butter, this freeze cracked
and busted high head to replicate a cutaway engine