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Author Topic:   piston pins?
tim gaeber
posted October 15, 2003 02:34 PM
What is the advantage in using pistons with floating pins as opposed to press fit pins?

Thank for any input

posted October 15, 2003 02:40 PM
Pins are floated to reduce friction between the pin and the piston pin bore . It allows the pin to rotate in both the piston pin bore and the rod bore , reducing the chance for a galling situation . This is important for higher RPM applications , like race engines .
With a pressed pin application , the pin and pin bore will only ever contact in one location , increasing the chance of galling and creating friction .


Hendren Racing Engines
Rutherfordton , NC

posted October 15, 2003 05:35 PM
I was waiting for the scientific answer.

if you dont think it makes a diff, then you must have never built a motor with floating pins.. it must be a lot of friction. I built 2 shortblocks identical pistons rods cams everything one floated one press. no comparison whatsoever.


tim gaeber
posted October 16, 2003 10:16 AM
So what does it take to float the pins? I have heard that you can just hone the small end but this would leave steal to steal and I know that's not good. Can you put bushings in a factory rod? We must run factory rods.

posted October 16, 2003 11:13 AM
you can put bushings but its expensive.

i started using floated when the rules were factory rods only.

i bought powder metal rods from competition products that are allready floated with good bolts. they are more money then aftermarket now though.


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