Engine and Transmission Tech

Local shop wants $180, for a 50lb. rover crank ! Go directly to the heat treat co., and it's $1.55lb.,(100 lb. min). It pays to shop around. Would this not work on flat tappet cams ? Seems like cheap insurance. Cheer, roverman.

Not sure about heat treating a cam Art. Its more about the case hardening depth I think. I will ask Geoff my cam guy.
How ever, I have been using composite lifters for a while now and the cam wear issues have gone away.
The cool part is the lifters don't wear and you can switch cams around at will.

I speak of that "cast iron lump, with bumps", called a cam. I'm not sure if "cool casing" would be more effective than "Parkerizing'. "Composite Lifters", you have my attention, what is the compostite material ? " Mushroom" configuration, would be nice, say .842" body diameter ?? Bill Gates pricing ? Is your "cam guy" grinding again ? Thanks, roverman

Yes Fred,

You've got my interested piqued! Composite lifters? Who makes them? Are they a custom deal for the Rover?

NCtim

The company that handles them now is 4secondsflat
It used to be Shubeck racing but is now Smith machine.
I have used lifters from both and they do exactly as the sight says. They don't wear and neither does the cam.
They are a little pricey but way cheaper than a wrecked engine. And like I said you can buy a set and switch them from cam to cam or even engine to engine.
These guys also have mushroom lifters, but not in the composite material.
I have a set for a VW that are composite and in a mushroom configuration so it can be done. But these were from Shubecks
The 4secondsflat guys say that they will custom build so "maybe".
Give them a call. Pretty cool guys to talk to.
Cheers
Fred

So Fred, are these just standard lifters that have had the faces coated with ceramic, or is there more to it than that?

When you say there is no wear, can I assume that means they eliminate the need for a zinc additive in the oil as well?

Jim

If you buy (16) composite lifters, you get the "discounted" price of only $1259 ! Yes, that's right, decimal ALL THE WAY to the right. Untill I win the lottery, I'll just play around with the $5.00, tool steel "mushroom" thanks. Let's consider the cam lobe next. Flat tappet is a misnomer, usually it's a 30" radius on the bottom. The lobes for these types of lifters are reported to have .5 deg. side angle. This is to rotate the lifter and therefore make a cast iron cam and lifter "live", in theory. The problem with theory, is it sometime "breaks-down" in practice. I suspect if these lobes had a very "slight" radius and angle,(side veiw), there would be reduced wear. This is because instead of constantly wearing on one side of the lobe, your moving the contact pattern across the lobe face, as the cam rotates,(because of slight radius on lobe). This combined with the .020" pressure lube hole, squirting oil on the lobe, should enhance durability for more aggressive cams. Science, roverman.

For sliding contact surfaces, long established (and even ancient you might say) practice dictates that the two surfaces be of different materials or have different molecular structures. Good examples are brass and steel, babbit and cast iron, or even case hardened cast iron against heat treated tool steel. Annealed carbon steel against heat treated carbon steel also works because the heat treatment changes the molecular structure. Why then this practice of using case hardened cast iron lifters on a case hardened cast iron cam lobe? Perhaps because it worked on steam engines, which were slow and the practice was simply carried forward without any thought. And because it was cheap. But it is far from being an optimal solution as we have seen. Art's tool steel litters are much much better, though at about four times the cost, but as noted, way cheaper than the ceramic coated alternative, and in theory should perform just as well. Art, what claims are made for these $5 lifters?

Bear in mind, unless constructed with needle bearings around the axle, even roller lifters have sliding friction.

Jim

Jim and clan, Empi is not divulging what tool steel, kind of like when marketing folks say "aircraft aluminum", = generic sales tool. In theory, the flat tappet is not sliding on the lobe interface, and yet in spite of cost, oem's went to roller lifters. In bang for buck, this appears the best way. Typical rover/sbb could be converted for approx $800 + labor ? The only reason to bother with a mushroom, should be when the rules dictate, such as GT-2. I believe the ceramic "faced" lifters use an insert vs. a coating. Onward, roverman.

Yes Art, sliding friction is present, even though it is a twisting motion. The parts still slide against each other unless you have the narrowest possible point contact and even then it might be arguable. But nonetheless a roller does have advantages. Cost is not usually one of them but with that price for composite it would be. And if ceramic, why not carbide? It could be brazed to the lifter face, is considerably harder than tool steel, more impact and chip resistant than ceramic, is markedly cheaper, and could easily be made in a mushroom configuration.

Jim