The issues with the flat tappet cam are lack of extreme pressure additives in current oil, including Mobil 1, removed because they are metallic (zinc) compounds that poison the catalytic converters; and cheap Chinese lifters.
For the oil, any diesel oil will have plenty of anti-wear additives. I use it in everything, as I'd rather replace a converter than an engine. It's part of why diesels last so long. Also, you can get synthetic diesel oil, which in my opinion is even better, but probably not necessary. Extended operation at high temperatures is when you really need synthetic. Otherwise, use the diesel oil and change it frequently. I'm sorry, but I know lots of racers that use synthetic racing oil, which generally also has the antiwear additives, with a flat tappet cam. I assure you the loads are sufficient to make the lifter rotate. Mobil 1 is better than non synthetic for wear, but not as good as a mineral oil with lots of additive (the diesel oil).
GM EOS (Engine Oil Supplement) is also a good thing, full of ZDDP and used as a cam/new engine break-in additive for years, and you can do worse than to keep on adding it, much better than STP which is a viscosity index improver.
Lifter rotation is supposed to be approximately one revolution of the lifter for two revolutions of the cam. It's common on Chevies to have to bore and sleeve the lifter bores to make this happen. I've seen a lifter rotate backwards. You can also bore the lifter bores over size and use Ford (bigger) or Chrysler (biggest) lifters.
Other helpful things are hard faced cams (check with Isky) and hard faced lifters. The Nascar guys go 9500 rpm with a steel flat tappet cam and lifters.
Also, break it in on only the outer springs, then add the inners.
You can also pull the intake and check the lifters until you're comfortable they're wearing correctly. A good idea in any case.
Quality cam and lifters, confirmed rotation, lots of ZDDP, break in carefully with reduced spring pressure, no problems. It's a good thing that Flat tappet cams do not have a catastrophic failure mode, it's why the McLarens used them in the day. They did throw them away every race, though. Roller lifters can and will fail catastrophically, does awful things to the engine. Trust me on this, not the magazine dweebs.
It looks like you have a lot of scrub radius, so it may try to jerk the steering wheel out or your hands.
David Merritt
For the oil, any diesel oil will have plenty of anti-wear additives. I use it in everything, as I'd rather replace a converter than an engine. It's part of why diesels last so long. Also, you can get synthetic diesel oil, which in my opinion is even better, but probably not necessary. Extended operation at high temperatures is when you really need synthetic. Otherwise, use the diesel oil and change it frequently. I'm sorry, but I know lots of racers that use synthetic racing oil, which generally also has the antiwear additives, with a flat tappet cam. I assure you the loads are sufficient to make the lifter rotate. Mobil 1 is better than non synthetic for wear, but not as good as a mineral oil with lots of additive (the diesel oil).
GM EOS (Engine Oil Supplement) is also a good thing, full of ZDDP and used as a cam/new engine break-in additive for years, and you can do worse than to keep on adding it, much better than STP which is a viscosity index improver.
Lifter rotation is supposed to be approximately one revolution of the lifter for two revolutions of the cam. It's common on Chevies to have to bore and sleeve the lifter bores to make this happen. I've seen a lifter rotate backwards. You can also bore the lifter bores over size and use Ford (bigger) or Chrysler (biggest) lifters.
Other helpful things are hard faced cams (check with Isky) and hard faced lifters. The Nascar guys go 9500 rpm with a steel flat tappet cam and lifters.
Also, break it in on only the outer springs, then add the inners.
You can also pull the intake and check the lifters until you're comfortable they're wearing correctly. A good idea in any case.
Quality cam and lifters, confirmed rotation, lots of ZDDP, break in carefully with reduced spring pressure, no problems. It's a good thing that Flat tappet cams do not have a catastrophic failure mode, it's why the McLarens used them in the day. They did throw them away every race, though. Roller lifters can and will fail catastrophically, does awful things to the engine. Trust me on this, not the magazine dweebs.
It looks like you have a lot of scrub radius, so it may try to jerk the steering wheel out or your hands.
David Merritt
