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DISCUSSION => Engine + Driveline => Topic started by: Febi Guibo on March 27, 2006, 04:16:49 PM

Title: Reduced reciprocating mass...
Post by: Febi Guibo on March 27, 2006, 04:16:49 PM

hi...

(please insert my usual 'I have little technical experience' with engine stuff here)

but like, for the high compression and related M42 buildups... are there performance benefits for reducing the reciprocating mass for the various moving parts? rods, pins, pistons, even valves?

Title: Reduced reciprocating mass...
Post by: kowalski on March 27, 2006, 04:35:48 PM

yeah, lighter rods pistons and pins will increase revability by reducing stress on the crank rods and pin, also increase throttle response as it wont have to spin up that mass. as for valves, i'm not really sure...

Title: Reduced reciprocating mass...
Post by: nickmpower on March 28, 2006, 12:16:35 AM

yeah when they moved to the 6mm valves on the e36 cars they just had an outer spring which was the same as the 7mm spring only that had an inner spring too. so i guess it does make a difference

Title: Reduced reciprocating mass...
Post by: 2002maniac on March 28, 2006, 10:59:27 AM

It does make a difference.  I had considered knife-edging the crank for my project motor but it looks like too much work and I'm not willing to pay to have it done.  :cool: