Pistons
Drifting
Joined: Feb 2005
Posts: 1,738
Likes: 2
From: San diego ca
Originally Posted by flood
Why do they have 4 valve reliefs?
4v head time!
4v head time!
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Originally Posted by fauxrs2
IIRC they have 4 valve reliefs so they can be installed in any location in the motor with no concern which way its inserted...all 2 vr pistons have a dot or other indicator of which side of the piston faces forward...by having 4 vr you can install it any way you like in the motor.
Most 4vr pistons also have offset wrist pins ... offset ABOUT 0.060". Logic for offset ranges from helping minimize piston slap to effectively advancing/retarding cam timing ... I've never found universal concensus.
Most pistons with both 4vr & offset pins also have a dot, notch etc to indicate "to front".
