Port Plates..

My experiance with them is relative to a BOSS302 motor, small CID, relatively huge heads/ports/valves. On a B2 motor, reviews tend to be mixed. On something with +50 CID, I beleive their value would be even less. BTW, they are available for both the intake as wwell as exhaust side of the head. Good luck.

http://www.mpgheads.com/

a pic is worth a 1000 words

I'm still not quite sure what makes them work?

Their intent is to effectively reduce port/runner size thereby increasing velocity at street RPMs. In theory, the increase in velocity would lead to better fuel atomization, distribution, increase in response, low end torque/power/drivability.

They also offer individual 'Stingers' that fit into each intake port that are more 3 dimentional than the regular port plates. Some of the BOSS302 guys swear by port plates, some say they've realized no difference. I seem to recall that there was an issue on the B2 plates where the water passages in the plates were either the wrong size or were mismatched leading to a cooling issue, but I'm not sure. I've got a great memory, it's just short.. :^)

Thanks George...a picture is worth a 1000 words. All I can say guys is my Pantera pulls like crazy from 1,200 rpms' to 5500. I believe its stock internally. It does have a aluminum intake, holly carb. w/mech. secondaries, mallory unilite, and a nice header/gts exhaust system.

I always wondered if they vibrate and effect the engine sound? Anyone know?

I used port plates in a previous life when I ran a 69 Boss 302. As I remember the argument was you gave up a little flow for velocity, particularly on the exhaust side. I think the idea was you raise the floor of the exhaust port after it turns from the valves. Back them guys used to cut off the entire outside of the head and put on a plate so the exhaust would have a straighter path. This was before all the latest heads we have now. The original heads were comprominsed because of the shock towers in Ford cars of the time. I never dyno'd the engine back then. We didn't have the dyno's like we have now but I never detected the slightest bit of difference but I never had my butt calibrated like some here have. I'm sure some one like George, Doug or Dan will remember these things. We used them only in classes that mandated stock heads. Vince

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I'm sure some one like George, Doug or Dan will remember these things. We used them only in classes that mandated stock heads. Vince

I never used them but they are what got me involved with the Motorsport heads. The "factory race cars" were using epoxied down intake ports.

I've got some magazine article that shows the ports nicely. If you guys are interested I can try to scan them and post the pictures.

On the intake side, I would use "port stuffers" in the head, if I were runnng an intake manifold, like the Parker Funnel web, that was designed to be used with stuffers, because it is an engineered system.

I would NOT use intake port stuffers with a manifold that was designed for a full size port. You are second guessing the designer at that point.

Make sense?

The Parker Funnel Web, by the way, is possibly the best intake ever designed for the 351C 4V iron heads, in terms of sheer bhp capability.

On the exhaust side, I've seen guys braze in the bottom of the exhaust port, run MPG stingers in place of brazing AND I've seen guys run the ports as is, in all cases the ports were extensively ported inside. I've seen impressive bhp numbers with heads in all 3 configurations. In fact, guys are getting better bhp numbers today, running the exhaust ports as is, than they did 20 years ago, running the high rise exhaust port plates.

There are knowledgable Cleveland engine builders still running the exhausts both ways (stuffed or unstuffed), so no consensus there. My take is, if you can build the power without modification, don't modify.

Of course with all the alloy head choices there are today, I see no reason to stress out over how to modify the iron heads.

your friend on the DTBB

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I would NOT use intake port stuffers with a manifold that was designed for a full size port. You are second guessing the designer at that point.

In general many of the aftermarket intake designers are "trying stuff" like everone else.. I think "trying stuff" is how "car guys" and "hot rodders" learn stuff and is the basis for much great knowledge people have. Nothing like turning a wrench vs cyber theories.

I know some GM intake manifolds used on the vette that had intake ports that opened and closed based on throttle position. This is the best of both worlds! That was what I was talking about a while back what I thought of making my own aluminum manifold. Ports that open and close would be keen!

Gary

I would have to second that, that is exactly what everyone is doing, is second guessing the designer.
Actually it is more that you are re-establishing the design criteria that the designer used.
Induction wise a person is attempting to gain maximum port velocity and maximum flow not so much at every lift as every rpm without variable venturi's.
That is what raises the controversy.

The more I hear about airflow inside intakes and everyone trying to understand it from designers to some of the great engine builders, they have more of an "idea" of what happends but can't really pin it down.

To think they understand is an overstatement and I think much of what they do is more trial and error.

Yes, it's as much of an art form as it is a science.