Model A cam ground to "B" profile

Be sure you know what B grind you have. Is it an OEM original grind or an after market
re-grind? It makes a difference.
Original's were designed and made with a whole different math program.
Mixing grinds and lifter face diameters is NOT a good plan.

Another thing to remember, original OEM lifters were faced FLAT.
Most modern ones are tapered.
 
I think that Formula 1 racing cars are now using pneumatic operated valves that are controlled by a computer. That means the timing is variable and that the valves lift and seat quickly. The timing can be tweaked while the engine is on the dyno to get the most torque at each engine speed. And even tweaked for each race course. The race course in simulated in a computer.

I wonder what AI could do?
 
pneumatic springs have been around for some time now, still opened by cams.
variable cam timing has also been around for some time, is in many production cars today.

I read years ago about electromagnetic valve actuation experiments. Not sure it has made it to the track yet.

Personally I like the older desmodronic valve setup.

J
 
nkaminar said:
I think that Formula 1 racing cars are now using pneumatic operated valves that are controlled by a computer. That means the timing is variable and that the valves lift and seat quickly. The timing can be tweaked while the engine is on the dyno to get the most torque at each engine speed. And even tweaked for each race course. The race course in simulated in a computer.

I wonder what AI could do?
Click to expand...

My 2002 Toyota Highlander uses engine oil pressure controlled by the computer to vary the valve timing of the DOHC camshafts.

Gives you the "low end grunt" of one valve timing profile AND the higher RPM power of a different profile in same engine.

System is called VVT Variable Valve Timing. Introduced in 1995.
 
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johnneilson said:
pneumatic springs have been around for some time now, still opened by cams.
variable cam timing has also been around for some time, is in many production cars today.

I read years ago about electromagnetic valve actuation experiments. Not sure it has made it to the track yet.

Personally I like the older desmodronic valve setup.J
Click to expand...

Here is a video of a Renault F1 engine on the dyno. This engine used the EM valve system. This pull is programmed to simulate a lap on the track. The glow outside the fuel flow above the injectors is plasma caused by the high speed air flow.
The engine is peaking at 21000 rpm.

https://youtu.be/y2iBbwocYZw
 
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for the general modern day engine performance enthusiast, the cam selections in cam suppliers (grinders) catalogs are accurate and adequate based on style and need sought, desired. however, for serious engine builders even those cams need to be 'dialed in' due to production variances from manufacturing. 'the enthusiast' should know the adv duration vs 050, lift and how cam is ground. advanced, heads up or retartded. it is helpful to be able to read those specs and know what the cam is all about. for example, high performance cam in a solid lifter engine reaching for my power and r's... vs a cam ground to be effective in a computer controlled engine... ie dif's in durations, etc. 050.

dialing it in to ck the cam card specs is a smart move. not always required for more common grinds but for the perfectionist or reacher... usually a 'must'!


s-l1200.jpg
 
Pete said:
Renault F1 engine... EM valve system. The engine is peaking at 21000 rpm.
Click to expand...


The EM and pneumatic method is needed because springs can not keep up with the 18,000+ RPM. Here is a pneumatic setup. https://www.f1technical.net/forum/viewtopic.php?t=24821
If you take a look at the cap screw in the 8th picture you can see a prime example of why F1 racing is so competitive and expensive. They took the time to grind excess weight off the screws.
 
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