Model A Pistons.jpg Pictured on the left is an old school Model A piston with an archaic design from the '20s, '30s, '40s.
On the right is a Model A piston of modern design, a design adapted by all car manufacturers many decades ago. The skirt is short and the rings narrow. Inspect the features of the two yourself; you need not be an engineer. You only need common sense to answer the following 3 questions:
1. Which piston would have the least friction, and thus the least parasitic drag, and heat?
2. Why would the car companies have made the switch?
3. Which piston would you prefer in YOUR car?
There is only one choice I use for the engines I build. I use the same clearances I and others have been advising right along, because of the very uneven and inconsistent cooling of the Model A block bores.
Whenever you see a clearance spec from a manufacturer which states .002-.0025, know that is a clearance for a modern car. Engine builders everywhere should recognize this immediately. Modern cars have vastly improved water jackets, cooling systems, and alloys that are quite different from those of yesteryear.
One of the two designs is gonna let you down on a long tour. In 1930, people did not tour mile after mile; they had to work! There were very few roads you could tour on anyway.
Information that is printed on a piece of paper needs to be reconciled by comparing to hands-on people's real world experience. The two do not always jive.
On the right is a Model A piston of modern design, a design adapted by all car manufacturers many decades ago. The skirt is short and the rings narrow. Inspect the features of the two yourself; you need not be an engineer. You only need common sense to answer the following 3 questions:
1. Which piston would have the least friction, and thus the least parasitic drag, and heat?
2. Why would the car companies have made the switch?
3. Which piston would you prefer in YOUR car?
There is only one choice I use for the engines I build. I use the same clearances I and others have been advising right along, because of the very uneven and inconsistent cooling of the Model A block bores.
Whenever you see a clearance spec from a manufacturer which states .002-.0025, know that is a clearance for a modern car. Engine builders everywhere should recognize this immediately. Modern cars have vastly improved water jackets, cooling systems, and alloys that are quite different from those of yesteryear.
One of the two designs is gonna let you down on a long tour. In 1930, people did not tour mile after mile; they had to work! There were very few roads you could tour on anyway.
Information that is printed on a piece of paper needs to be reconciled by comparing to hands-on people's real world experience. The two do not always jive.
Comment