Wrist pin dimension query

Ross Wooldridge

Old Man with a Hat
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Helloe FCBO hive mind!

Standard first gen 440 (1966), stock pistons etc.

What is the length of a wrist pin?

What is the outer measurement between the two flat spots on the piston skirt where the pin presses in?

How much space between the cylinder wall and the pin bosses (flat skirt area)?

Thanks!
 
Recently just working with some piston pins. So, I have found some variance with the stock pins depending on year and cubic inches, 413-440. This one I believe did come from a '67 440 and it is about 3.560" long. There is about .425" on each side to the wall. Keep in mind stock pistons have offset pins, so the pin is not concentric to the bore.

Here's what I recently was working on. Modern replacement 440 six pack forged piston with shorter and lighter aftermarket pins. Cutting for Tru-Arc pin locks to allow floating pins.
SAM_2465.JPG
 
Thanks for that info - just to clarify - so with a 3.5" pin there's just under 1/2" clearance from the pin boss on the piston to the cylinder wall on each side?

I sent you a PM
 
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Thanks for that info - just to clarify - so with a 3.5" pin there's just under 1.2" clearance from the pin boss on the piston to the cylinder wall on each side?

I sent you a PM

Wow, 3.5 plus 1.2 on each side gives you a 5.9" bore. What kind of monster are you building?

OK, seriously... Turn to page 9-30 in your FSM.

3.555-3.575" is the length of a stock 440 piston pin.
 
Wow, 3.5 plus 1.2 on each side gives you a 5.9" bore. What kind of monster are you building?

OK, seriously... Turn to page 9-30 in your FSM.

3.555-3.575" is the length of a stock 440 piston pin.
He's putting a mountain motor in his Monaco. :lol:
 
Thanks for picking up on that John - my fat fingers! Corrected... and I didn't know that those dimensions were in the FSM - I wasn't in the shop when I was attempting to find that info. Thanks for that too!
 
Thanks for picking up on that John - my fat fingers! Corrected... and I didn't know that those dimensions were in the FSM - I wasn't in the shop when I was attempting to find that info. Thanks for that too!
You don't have three copies like I do? Hey, they were cheap.
 
Ya, closer if he divides by 2. I also gave him some useless info regarding pin buttons that I have for an old race engine, but he PM'd me with more details about what he was doing and I gave him some thoughts.
 
You don't have three copies like I do? Hey, they were cheap.
I have a paper copy (that I never use), one on my laptop and the electrical portion is also on my Kindle. I was going to do a complete FSM on the Kindle for traveling, but figured the electrical (schematic) would be the thing I really needed to reference to get myself home or at least onto a rollback.
 
I have one in the house, one in the garage, and a spare if I want to bring one with on the road. I brought the lone copy of the 68 with me to Carlisle and the C body show in Illinois, just in case.
 
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