Model A cam ground to "B" profile

[Jim Brierley]

Originally Posted by ModelA29

MARC has the stock spec for the A & B cam on their site: https://model-a-ford.org/top-page-1/...pecifications/

Those specs show only the very latest of the B grinds, the most common B had .302" of lobe lift. The one shown makes a vey good touring cam.

[Jim Brierley]

Originally Posted by Dan McEachern

ok you guys! knock it off!

Just trying to be factual!

[Pete]

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.

[Dan McEachern]

Originally Posted by Jim Brierley

Pete, I don't know any good cam grinders, do you???

Jim- I was referring to this-

Dan

[nkaminar]

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?

[johnneilson]

Sponsored Links (Register now to hide all advertisements)

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

[Benson]

Originally Posted by nkaminar

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?

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.

[Phil Brown]

https://youtu.be/iM5Tl_oytMM?si=5rH7l7v5Dihf0Dfd
If you have never seen a cam get ground kinda interesting video
not model A but it shows the machine and how it grinds the lobes to shape and there placement relative to each other

[Pete]

Originally Posted by johnneilson

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

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

[johnneilson]

Uh, no,

bridge property for sale, cheap!!

J