Explain to me again, please

[SBillinson]

Originally Posted by L.Fite

Are there that many failures using a standard solid lifter in a stocker motor? The NASCAR guys used standard solid lifters for decades. I know the ramps are more aggressive in Stock these days, but a tool steel lifter for a .312" lobe? Are people turning stocker engines to 10K?

Well... one point is NASCAR was running a solid MUSHROOM tappit, as far as I know, those aren't allowed in stock...

Also NASCAR engines use larger diameter cams and last I heard was running an enclosed pressurized cam tunnel to make their stuff live...

That was years ago, are they still even using solids?

Any way... comparing apples to grapes.
Not much NASCAR does even compares to stock eliminator really.

JMHO

No, they haven't run mushroom tappets in the Cup series for at least 30 years.

Larger diameter cam cores are used to reduce flex and produce better valvetrain stability, especially in engines with splayed or canted valve heads. They are widely used, even in Super Stock.

Cam tunnels are used primarily to reduce windage on the rotating assembly.

You're right about one thing, though. NASCAR is very different from NHRA Stock Eliminator.

The point, however, is that if a 750-850 HP, 358 CID, canted valve, flat tappet engine in a Cup car can run 500 miles at over 9000 rpm with a stock diameter solid lifter, then it's hard to imagine why it can't be done in a stocker that doesn't anywhere near that RPM and is raced a quarter-mile at a time.