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L82 forged piston question

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Old May 8, 2020 | 07:00 AM
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Default L82 forged piston question

Did the L82 forged pistons use a floating or press fit wrist pin? I see two different rod part numbers, 3946841 for floating pin and 14096846 for press fit pin.
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Old May 8, 2020 | 07:55 AM
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Press fit for 75,
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Old May 8, 2020 | 08:57 AM
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All L-82's use a pressed fit pin.

There were very few engines with factory floating pins. Some racing applications used them but street engine applications did not justify the cost.
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Old May 8, 2020 | 09:05 AM
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Originally Posted by KenSny
Press fit for 75,
So should we assume press fit from 75 and later and floating for 74 and earlier ? Or was it just that the factory just used what they had on a particular day.
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Old May 8, 2020 | 09:09 AM
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No, see stingr69's post.
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Old May 8, 2020 | 11:27 AM
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The only difference in the pistons is the full floater piston will have grooves for the spiro-locs. You can use them for press fit......
Of course you cannot use press fit for full floater.
These days, they all have spiro-loc grooves as to have just one part number.

Jebby

Last edited by Jebbysan; May 8, 2020 at 11:27 AM.
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Old May 8, 2020 | 11:29 AM
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Unless your small block is a late '68 to '69 Z/28 302 cubic inch production GM motor, you would not have factory floating pins.
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Old May 8, 2020 | 12:29 PM
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Originally Posted by KenSny
No, see stingr69's post.
Got it , thanks for the clarification!
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Old May 8, 2020 | 12:31 PM
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Originally Posted by Jebbysan
The only difference in the pistons is the full floater piston will have grooves for the spiro-locs. You can use them for press fit......
Of course you cannot use press fit for full floater.
These days, they all have spiro-loc grooves as to have just one part number.

Jebby
Thanks, appreciate the update! Good info!
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Old May 8, 2020 | 04:22 PM
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FWIW, IMO, floaters offer No Performance advantage for street motors.

They, however, really assist motor disassembly/assembly ... and especially dry-fitting/mockup.

Need to swap out a wonky piston or rod ? ... easier.
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