Northstar Engines and System Technical Discussion Discussion, roller lifters or flat tappet in Cadillac Engine Technical Discussion; That is the question, i need to find out.
To find out more about my engine, i am seeking answers ...
Automobile(s): 2002.5 F55 STS/65500mi, 2004 Ford F150 SuperCab4x4
MD Eastern Shore - Kent Island
Re: roller lifters or flat tappet
If you have a '98, you have a hardened sled cam follower, which rides on the valve tip at one end and a hydraulic lash adjuster at the other. The cam lobe bears on the sled. The only thing in the system that will move down is the valve stem.
'00 changed the hardened sled to a needle bearing roller.
I posted a pic of the new system a couple of weeks ago.
Look at it this way: Place a water tumbler on your kitchen counter (the lash adjuster). 6" to the right place a sponge (the valve tip). Place a ruler flat across the two (the cam follower). With one finger (the cam lobe) push down hard in the center of the ruler. What moves? The sponge end, right? Bingo, OHC/lash adjuster principle. (A mechanical setup has the cam lobe act directly on the valve tip which is topped by a removable cap which can be miked and changed to get proper valve lash.)
BTW, if you're one of the ZDDP checkers, Pennzoil LongLife 10W-30 truck oil has 1400 PPM ZDDP as opposed to non- gas/diesel oils which carry 600-800 PPM.