Re: Forged Piston Noise when cold, Piston material or pin placement?

[adh@xxxxxxxxxxxxxxxxx (Sandwich Maker)]

" From: biljoh@xxxxxxxxxxxx
" 
"   Forged pistons will make more noise on a cold motor than cast
" pistons until the engine warms up.
" []
" The pin placement may or
" may not make the situation worse I have never researched that but
" someone here will be able to adress that. 

it does.  stock slugs have the pin offset to the thrust side which
you'd think is backwards for power - and it is - but it prevents the
slug from slapping over when the power stroke starts.  an early speed
secret was reversing the slugs so the pin was offset the other way.
the power difference is probably slight, but it's real.

back to sbcs again - the zz4 crate engine originally had zero-offset
pins, but they got so many 'noise defect' complaints from ignorant
customers they had to go back to stock-offset style pins.

there's probably a nice formula somewhere that sets the optimal
offset/stroke ratio...
________________________________________________________________________
Andrew Hay                                  the genius nature
internet rambler                            is to see what all have seen

adh@xxxxxxxxxxxxxxxxx                       and think what none thought