Thread: Wanting to give my 460 some pep!!

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FIRST OF ALL, MY APOLOGIES TO THE OP FOR HAVING TO SUFFER THIS BANTER BETWEEN TWO OLD GUYS.....

Originally Posted by moparfever

No, it's not something I heard at Sonic. I don't work that way. Really, I'm 52 years old and have been doing everyhting on my cars since I was 15. You don't have to insult me.

Sorry, I get a little emotional sometimes.

Originally Posted by moparfever

Okay, power under the curve. Did you read that in a book somewhere?

Now, you're trying to insult me. All knowledge is aquired one of three ways, either it is heard or it is read or it is figured out to a conclusion by the person himself. It is my conclusion from having hot rodded one thing or another and been around others of the same ilk for over 50 years, that if you can apply more power over a longer period of time with one manifold than you can with another type of manifold, you will be quicker and/or make more power. I appreciate your example, but that is only one example. I have seen, in dozens of cases over the years, that a car will be faster after changing from a single plane to a dual plane intake. It all depends on the application. On a circle track car, a dual plane will slow the car down because the rpm operating range is maybe 4000 to 8500. On a street car, you may make a little more power because the operating range is more like idle to 5500. [/QUOTE]

Originally Posted by moparfever

Nobody races from idle. Not with either automatics or standards. A single plane can give plenty of power starting at a reasonable rpm.

I'm not talking about a racing motor only. I'm talking all applications of internal combustion engines. Your statement "A single plane can give plenty of power starting at a reasonable rpm" is true, of course. But the question is....Could the car be faster or the engine make more power with a different manifold in the particular power range where the motor will be operated in this particular application?

Originally Posted by moparfever

Do you really think with 450 ft-lbs of torque at 2500rpm you'ld be down to unusable at 1500rpms, which is really where most cars begin using power?

Probably not, but this is just one example where you are using a particular set of circumstances to make your point. There are other examples from my past that indicate that in a particular application, a dual plane intake would make more power under curve in the range where it is used and be a better choice. This is my experience talking and I don't immediately have a graph or curve to display, but given a little time, I will come up with visual evidence.

Originally Posted by moparfever

Now on the cylinder cross-section. It's just another way of saying big-block. If you look at how much air gets sucked through the carb during the initial 30 degrees of crank rotation after tdc

Ummmm, yeah.....not much really. The intake valve is barely beginning to open. It will be about another 75 or so degrees of crank rotation before the intake is fully open and it will be open for another 105 degrees or so after that, depending on cam timing of course.

Originally Posted by moparfever

a big block sucks considerably more volume than a small block due to the larger cross-section of the cylinder, hence a faster signal to the carb. Of course it's more complicated than that, and takes into account runner volume as well

Yeah, you bet it takes runner volume into account. The relationship of cylinder volume to intake runner volume is very closely defined, no matter whether it is a tiny little small block or a behemoth 800 cubic inch motor. The smaller the runner is for a given cubic inch motor, the better the throttle response at low rpm's and the sooner the manifold will stall. The larger the runner, the worse the throttle response and the more soggy low end operation will be. That's just my point. For the manifold displacement that the piston sees, dual plane manifolds have roughly half the displacement of a single plane manifold, so they generally will operate better on a street motor where rpm's are limited. I am not so hard-headed as to deny you that there are some applications where a single plane will work better, so long as you will concede that there are some applications where a dual plane will work better.

Originally Posted by moparfever

but in my real-life experience, a single plane works great on big blocks on the street. You do what you want, everybody has an opinion and everyone goes their own way.

Yeah, well in my real-life experience, a dual plane works great on big blocks on the street.

Stalemate, end of game.