Performance and the Art of Pushrod Installation
Feuling Parts says it has taken the tried and trusted Twin Cam Quick Install Pushrod "and added knurling and an indicator dot to make install a breeze. This is the strongest 'Quick' install pushrod on the market."
TC Quick Install Adjustable pushrods have a 3/8" OD tube and 0.134" wall thickness and come in sets of four. They are individual length exhaust and Intake pushrods and install without the removal of rocker covers – they require quick install tubes - see Feuling #4095 for tubes only or Feuling #4097 for pushrod and tube kit
"The jam nut slides up the pushrod; the base then loosens up into the pushrod to shorten length and allow quick install access."
Feuling notes that correct pushrod/lifter adjustment requires starting with fully pumped-up lifters. "When trouble shooting noisy valve-train, lifter adjustment should start with a fully pumped-up lifter, from zero lash put 0.90" - 0.100" of pre-load on Feuling hydraulic lifters." It could also be that lifter to lifter bore clearance is out of spec and Feuling recommends a clearance of 0.001" - 0.0015" for proper oil psi at lifter.
Other factors could include pushrods flexing and hitting pushrod tubes ("look for a shiny ring witness mark around the pushrod normally seen up towards the cylinder head"), low oil pressure, pushrod center oil hole plugged, excessive crankshaft runout, rocker arms/bushings out of tolerance and leaky/broken piston cooling jets.
Additional suggested checks could include the clearance for roller rocker arms on the underside of the rocker box covers; steep ramped camshafts causing excessive gear drive backlash or excessive crankshaft runout; tolerance on the rocker arms/bushings, valve spring clearance to lower rocker box housing and valve spring coil bind and/or valve spring harmonics – the valve spring open height should match up with camshaft peak lift.
FEULING PARTS
