Are Pontiac 400 rocker arms adjustable?
Your rocker arm nuts must be matching Pontiac nuts as they have a matching shoulder that fits the bottle neck taper. If not, and they are aftermarket or Chevy replacements, they can back off. With what you have, they simply get torqued down to 20-25 ft pounds, no adjustment.
Do you need to adjust rocker arms on a Pontiac?
Whether you have decided to stay with the stock type stamped rocker arms or Competition Cams Magnum Rollers Rockers as pictured here, or something far more exotic, you will need to adjust valve lash. Torquing the adjusting nut per the old Chilton’s to 20-25 ft pounds won’t work on any heads that have been milled.
What was the rocker arm ratio for the Pontiac V-8?
Developed by Pontiac Engineer Clayton Leach, the V-8 used a simple ball-stud rocker arm that was very efficient and cost effective. A rocker arm ratio of 1.5:1 was used on most production engines. Early Super Duty and Ram Air IV engines used an identical rocker arm but with a 1.65:1 ratio to increase valve lift.
What was the rocker arm ratio on a Super Duty engine?
A rocker arm ratio of 1.5:1 was used on most production engines. Early Super Duty and Ram Air IV engines used an identical rocker arm but with a 1.65:1 ratio to increase valve lift. Flat-tappet camshafts remain very popular.
Where is the TDC on a Pontiac rocker arm?
Locate TDC on #1 by locating the ‘0’ on the timing tab with the harmonic balancer line. You can determine whether it’s really the #1 cylinder a couple of ways. One way is too look at the hydraulic lifters. If the hydraulic lifters are down and level you’re on # 1 TDC.
Whether you have decided to stay with the stock type stamped rocker arms or Competition Cams Magnum Rollers Rockers as pictured here, or something far more exotic, you will need to adjust valve lash. Torquing the adjusting nut per the old Chilton’s to 20-25 ft pounds won’t work on any heads that have been milled.
Developed by Pontiac Engineer Clayton Leach, the V-8 used a simple ball-stud rocker arm that was very efficient and cost effective. A rocker arm ratio of 1.5:1 was used on most production engines. Early Super Duty and Ram Air IV engines used an identical rocker arm but with a 1.65:1 ratio to increase valve lift.
Locate TDC on #1 by locating the ‘0’ on the timing tab with the harmonic balancer line. You can determine whether it’s really the #1 cylinder a couple of ways. One way is too look at the hydraulic lifters. If the hydraulic lifters are down and level you’re on # 1 TDC.
What kind of nut do I need for rocker arm adjustment?
Torquing the adjusting nut per the old Chilton’s to 20-25 ft pounds won’t work on any heads that have been milled. This is especially true with the high lift cams of today. The valve train needs to be adjustable. Some form of lock nut must be used. I prefer Mr. Gasket’s poly lock nuts.