m610 wrote:It's an Isky cam, OR-66 re-grind. It's like new and in good shape.
These motors come with hydraulic lifters and cams. Mine are solids paired with a cam ground for solid lifters.
Spring rates are greater than stock, but not a lot, best I can recall. "Blue", an identical motor has not had this problem with lifters.
All of the lifters are damaged, except for the one that was a filed repair replacement, used, best we could do at the time. (20 minutes later we lost a rod bolt, but that is another story.) That one looks fine.
We run VR-1 plus ZDDP. I understand too much phosphorous causes intergranular attack and spalling of the steel. But again, we've been running this oil and additive fore years.
I suspect the metallurgy is wrong. Either too hard or not hard deep enough. Still was thinking it could be things like too great a valve lash, maybe sustained high revs. Team orders are to shift at 5500, 6000 in the heat of battle.
Mike
Based on the looks it is fatigue that happens inter-granularly. Kind of like a spalled bearing or statically over loaded bearing etc. But cam to lifter interface can be a funny thing. One thing to absolutely look at is making sure that you have adequate clearance without spring coil bind and other interference. Spring bind is easy to check with the springs off the car. Figure .060" lift before bind is pretty good. But bind can come from other things as well like oil seals and event spring retainers hitting valve guides. So use a light checker spring in the head and go to full lift and press down to see how much more clearance you have at full lift. (dial indicator is best) Bind will damage valve train components quick.
If you don't have one run and go buy some aftermarket ignition doodad like the MSD 6AL that has a good "soft" rev limiter. Over revving and money shifting will cost you an engine so the fancy ignition will be a bargain in the end. Rev limiting is good also if your getting valve float which could also be hammering the lifter pretty hard if it happens. Soft rev limits are best they randomly kill a cylinder so that the engine stays "loaded" at high RPM. Most factory rev limits are a hard cut which wreaks havoc with piston skirts and wrist pins.
Also if you have a friend with a hardness tester compare the good and bad lifters. The numbers are not so important than the difference. And its good to keep good records of this stuff to refer to later.
Edit: That's a pretty low rev limit. If they are following your instructions valve float would be hard to get.
Greg
1987 Alfa Milano (Bellissima since 2008), Racing since 2008 Stafford Springs, 2nd overall 2011 NJMP, 4th at NHMS 2011, 2nd at Summit 2011, Into the wall hard at Stafford Springs 2011, 2nd at Monticello 2013, 3rd at NHMS 2013, 2nd at NHMS 2016. 2nd at NJMP 2018
25,000 racing miles in 32 races in 10 years. Yes its the same motor. Tell me again how Alfas suck? Update: Big moneyshift = new motor