What is the difference between a Model T and Model A Crankshaft?

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Catbird
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What is the difference between a Model T and Model A Crankshaft?

Post by Catbird » Mon Nov 23, 2020 9:29 am

I have heard about people installing a Model A crankshaft in a Model T. What are the advantages? Also, how can I tell if my 1927 Model T speedster has a Model A crank from past owners?
Bill

You can dissect a Model T; but you can’t kill it!

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Henry K. Lee
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Re: What is the difference between a Model T and Model A Crankshaft?

Post by Henry K. Lee » Mon Nov 23, 2020 9:37 am

More torque from the stroke for sure. Larger journals, but some serious mods. Drop the inspection plate and you will know.

Hank


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Re: What is the difference between a Model T and Model A Crankshaft?

Post by tman1913 » Mon Nov 23, 2020 9:45 am

If the front of the crankshaft at the pulley is threaded and the pan has four bumps on each side where it is bolted to the block, there’s a good chance you have a Model A crank
Remove the inspection cover and have a look

A Model crank has larger mains and rod pins along with a 1/4” longer stroke.

Take a lot more work to put one in but very doable

What Henry said. He types faster. Lol


Kevin Pharis
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Re: What is the difference between a Model T and Model A Crankshaft?

Post by Kevin Pharis » Mon Nov 23, 2020 10:55 am

Here is a pic of the pan bumps... and there will usually be a 3/8”-1/2” thick spacer between the pan and inspection cover as well
416882DE-D1C8-42D6-9B8E-BFFEADCF90C6.jpeg
If you have the inspection pan off, and are not familiar with either crank... the A crank has circular webs near the main journals, and the T crank will look like it was bent up out out of a coat hanger👍

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TonyB
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Re: What is the difference between a Model T and Model A Crankshaft?

Post by TonyB » Tue Nov 24, 2020 12:27 am

I can usually tell if it’s an A crank by the “bumps” on the side of the pan.
Tony Bowker
La Mesa, California
1914 Touring, 1915 Speedster, 1924 Coupe.


Topic author
Catbird
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Re: What is the difference between a Model T and Model A Crankshaft?

Post by Catbird » Tue Nov 24, 2020 9:46 am

Good info! Will check into my engine.
Bill

You can dissect a Model T; but you can’t kill it!


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Re: What is the difference between a Model T and Model A Crankshaft?

Post by otrcman » Tue Nov 24, 2020 6:41 pm

Somebody correct me if I'm wrong, but I think one of the most significant differences is that the Model A cranks are virtually never found cracked.

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Tim Rogers
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Re: What is the difference between a Model T and Model A Crankshaft?

Post by Tim Rogers » Tue Nov 24, 2020 7:49 pm

Model T...
t 3.jpg


Model A...
a crank.jpg
<o><o><o><o> Tim Rogers - South of the Adirondacks - Forum member since 2013 <o><o><o><o>


Topic author
Catbird
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Re: What is the difference between a Model T and Model A Crankshaft?

Post by Catbird » Wed Nov 25, 2020 7:09 am

Thank you, Tim Rogers. Opened your post while my wife brought my coffee this morning! She also likes cars. I asked her could she see the difference between Model T and Model A crankshaft. She immediately saw the difference! She said, "The Model A looks 'newer.' " :roll:
Bill

You can dissect a Model T; but you can’t kill it!


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Re: What is the difference between a Model T and Model A Crankshaft?

Post by J1MGOLDEN » Wed Nov 25, 2020 10:04 am

The back Main Bearing is also shorter by about 3/8th inch.

I don't recall the exact difference.

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