How Can Dual Exhaust Ports Be Made Into A Genuine Performance Option For 2 Valve Heads?
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Re: How Can Dual Exhaust Ports Be Made Into A Genuine Performance Option For 2 Valve Heads?
I think it was Rudge that first used twin exh ports in the 1930s.
Re: How Can Dual Exhaust Ports Be Made Into A Genuine Performance Option For 2 Valve Heads?
For reference, here's my modified engine- the standard layout is the same.
Regards
Paul
Regards
Paul
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Re: How Can Dual Exhaust Ports Be Made Into A Genuine Performance Option For 2 Valve Heads?
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hmmmm. I only have one exhaust port.
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Re: How Can Dual Exhaust Ports Be Made Into A Genuine Performance Option For 2 Valve Heads?
I can hear my dad now: "great, now no matter what RPM the engine is at, at least on of the pipes will be the wrong length."
Mike Jones
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Jones Cam Designs
Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com
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(704)489-2449
Re: How Can Dual Exhaust Ports Be Made Into A Genuine Performance Option For 2 Valve Heads?
Doesn't the HD Milwaukee Eight have coolant flowing around the exhaust ports? The Polo engine that I've seen first hand was based on a Porsche 911 engine and two valve. If you have pics of a working 4 valve Polo, I'd love to see how he does it.nicholastanguma wrote: ↑Fri Apr 16, 2021 11:00 pm That seems to make sense. However, what doesn't seem to make sense is that other air cooled four valve designs don't suffer any overheating problems. For instance, the Suzuki DR650 and 800, the Suzuki LS650, the Yamaha XT600 - 660, the new Harley-Davidson Milwaukee-Eight Vtwin, and the Polopolous Porsche flat 4 are all in continuous use without blowing up or melting down. I could go on with many other examples. What's going one here?
The others are big singles, and even with lots of fins hanging out in midair they still have their fair share of cracked heads, usually around or between the exhaust ports. Or the heat causes the exhaust valve guides to wear out.
Re: How Can Dual Exhaust Ports Be Made Into A Genuine Performance Option For 2 Valve Heads?
Classic example of "is the glass half-full or half-empty" and "you can't win for losing".