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Originally Posted by ULTRAZLS1
So you are saying top fuel could be even faster if they went to OHC? Explain.
Id like to know how all those complex internal moving parts would work and hold up under 5000+ horsepower
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Are you serious? The valvetrain in an OHV design, by it's very nature, is vastly more covoluted than an OHC setup needs to be. In an OHC setup all I have to have is a couple of sprockets, a chain., the camshafts themselves, and a direct acting cam bucket to actuate the valve and the spring underneath.
On an OHV design I still have the sprockets, chain, and a cam, although I do have fewer of them, but then for every valve in the engine I have to have a relatively long and thin pushrod reaching up to a rocker arms that reaches across the head to actuate the valve. Those parts do their job, but they are relatively fragile and absolutely create a weak link.
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Originally Posted by ULTRAZLS1
What is the fastest time any ohc design has ever went in the 1/4? No car under any class has ever gone faster than pushrod (except for the rocket propelled cars of the 70's) Surely someone has pushed OHC to the limit.
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Why would somebody build the OHC counterpart to a Top Fuel motor when they would know they can't use it? Several folks have petitioned to able to use the same in the past, but the projects never got very far because the NHRA and IHRA like their Hemi's as they are. As for the good old days, SOHC Ford big blocks did absolutely rule Top Fuel for a time several decades ago, before they were banned from competition.
Here is some food for thought for you. If OHC engines aren't a threat then why aren't they allowed?
