Relationship of RPM on power to operate valvetrain

[hoffman900]

Interesting, Jay. I would think the full system would be ideal due to the fact with a single system you’re not seeing the full effect of the cam itself flexing.

I feel pretty confident in assuming the test Harold was involved in was the full system.

[Warp Speed]

Interesting, Jay. I would think the full system would be ideal due to the fact with a single system you’re not seeing the full effect of the cam itself flexing.

I feel pretty confident in assuming the test Harold was involved in was the full system.

Typically, the noise from the other valves can cause havoc with the laser sensors. Is this noise real during full system operation, or is it just noise?
Then throw in firing loads and vibrations from a running engine! Lol
Testing procedures and data recorded are ever evolving!
"The ONLY thing we do know, is that we don't know"! LOL

[hoffman900]

Interesting, Jay. I would think the full system would be ideal due to the fact with a single system you’re not seeing the full effect of the cam itself flexing.

I feel pretty confident in assuming the test Harold was involved in was the full system.

Typically, the noise from the other valves can cause havoc with the laser sensors. Is this noise real during full system operation, or is it just noise?
Then throw in firing loads and vibrations from a running engine! Lol
Testing procedures and data recorded are ever evolving!
"The ONLY thing we do know, is that we don't know"! LOL

That’s interesting as I know the lasers are isolated from the engine on their own stand.

Getting the data isn’t the easy part. Interpretation is the trouble, but you know that.

[HDBD]

What is in the design of a NASCAR motor that allows the use of springs that are small light and only have 130# or so spring pressure and allow over 10K rpm with pushrods?

[hoffman900]

What is in the design of a NASCAR motor that allows the use of springs that are small light and only have 130# or so spring pressure and allow over 10K rpm with pushrods?

Lots of engineering and the money to work it out. Others have shared the ability to do similar after Spintron work over on Yellowbullet. Seems a no brainer for the drag week guys. Seeing how few guys actually put their engines on the dyno, it is probably asking a lot for someone to put it on a Spintron, but if you have a common application, you bypass the cost and effort to get a block cut and dummy crank made.

Billy Godbold described the NASCAR approach as the ballet dancer approach to valvetrain design. Mike Jones said he has changed how he designs the ramps after he started getting some time on Spintrons.

Billy also said Pro Stock engines are unlike anything else and despite all their NASCAR knowledge, it was hard to design a Pro Stock grind where they didn't need 1500lbs open. That said, this is when they were over 12,000rpm and are well over an inch lift.

[HDBD]

I know there isn't a lot of public information about the NASCAR engines but is part of the strategy to use smaller lobes and get the lift by rocker multiplication?

[hoffman900]

I know there isn't a lot of public information about the NASCAR engines but is part of the strategy to use smaller lobes and get the lift by rocker multiplication?

With the flat tappet stuff, yes. I believe they've dialed the rocker arm ratios back a little with the roller cams, but it's still the same idea.

I think that philosophy always is better. It allows you to keep the seat duration where it needs to be while getting the valve lift / area you need. It also keeps the base circle larger and keeps strength in the cam. IMO the cam can’t be stiff enough, especially in factory type blocks where the core can only be so big.