Head flow equals horsepower.

Randy V

Staff member
Lifetime Supporter
Great video!
This is Kerry Torres, Instructor from United Technical Institute - Phoenix AZ - on his own time.
He knows what he’s talking about. I hope he does one on induction systems, compression ratios, power adders.
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Ron Earp

A couple of years ago Hyundai made that worrying about camshaft duration a thing of the past, they invented a variable valve duration system they have in a production car. It is clever.


Howard Jones

Ron great to see you are lurking! Hi buddy! I am trying to educate myself a little as I am working with an engine builder to select some parts. The really had thing is heads and cam timing while trying to predict torque curve and limit hp to what the gearbox will be happy with. My preliminary target is 540-560Hp and 400-500ft/lbs from 4000-6000. He believes this is very doable and we may need to trim Hp somewhat. We'll see!!!!!!


Interesting videos.
How good at scavenging is the GT40 ‘bundle of snakes’ exhaust now that we are not running flat plane cranks etc?

Terry Oxandale

Skinny Man
I was so disappointed in the first video, that I quit watching after the dissertation on spring pressures. Yes, it takes energy to open a spring, but that same spring is pushing the cam around its rotation after the peak of the lobe has passed the follower, so in theory, that counters some of the next cylinder whose lobe is opening the spring...yet he doesn't even mention that. Also, peak valve lift discussion cannot be compared to peak port flow until one includes the ramp profile and how much longer that "useless" lift is a by-product of keeping the longer period area of that profile beyond port's flow. He may address this later, but right now, I've lost interest in it.