engine

rustyjeep · 10-10-2001, 05:25 PM

1980 cj7 with 151 c.i. 4 cyl (gm motor). Rebuilt but I cannot find specs for valve adjustments. Hayes manual no help.

Nightclaw · 10-10-2001, 11:27 PM

Er... The GM 151cid/2.5L (Pontiac's "Iron Duke") used hydraulic lifters. There should be no valve adjustment. If you're getting excessive valvetrain noise, you probably have a collapsed lifter or blocked oil channel somewhere.

On the off (and somewhat improbable) chance that you have mechanical lifters/solid camshaft, Crane lists three lash adjustments for solid and roller camshafts in the Iron Duke:

Mechanical Lifters, 112° LSA Cam: .028" Intake / .030" Exhaust
Mechanical Lifters, 106° LSA Cam: .020" Intake / .020" Exhaust
Roller Camshaft/Lifters: .035" Intake / .030" Exhaust

Source: http://www.cranecams.com/master/apps/pontiac1.htm

rustyjeep · 10-11-2001, 05:42 PM

10-4, they are hydraulic. The nut screws on the stud and compresses the lifter. I am assuming that there is 0 clearance. But, there is no lock nut or keeper and I think that they should be torqued at 4-10 ft lbs at TDC for each cylinder but I can't find any thing on it. Also, what locks the nut?