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 Ram Air IV Valves
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drobe2
Cochise

USA
333 Posts

Posted - 30 May 2007 :  7:58:25 PM  Show Profile  Reply with Quote
Anyone using the these valves? What head modifications like spring seats, installed height, keepers and rocker and push rods wil have to be made? If I understand it, the valve is longer and the diameter is also. I under stand, if correct, the push rod is longer also. Can it be used in a 6X head? If so, what is the advantage? Any one know about the Ford Cleveland intake valve being used in the Pontiac head?

Mr. P-Body
Running Bear

USA
2244 Posts

Posted - 31 May 2007 :  08:37:44 AM  Show Profile  Visit Mr. P-Body's Homepage  Reply with Quote
Drobe,

RA IV valves are about .220" longer than the orignal valves in the 6X heads. The advantage of the extra length is you can use much taller "installed height" springs, making room for more camshaft and longer spring life. The "tulip" shape of the intake valve can also be a "plus", if the heads are properly ported, the valve will increase flow about 4 CFM over a traditional "flat back" valve.

One important issue regarding using the longer valves, the pushrods will need to be longer, as well. Be watchful of rocker arm-to-valve cover interference.

The valve diameter is the same as any of the other performance heads from Pontiac, 2.11" and 1.77", respectively. The 6X was never considered a "performance" head from the factory. Enlarging the exhaust to 1.77" is one of the "must do" modificatioins to get the 6X up to performance levels.

As for using "other" brand valves in Pontiac heads, one must understand. In today's market, there are no "Cleveland" or "Pontiac" SPECIFIC valves (well, okay, there are, but not for our purposes here). We use BBC sizes, Ford sizes, Pontiac sizes, etc. in various families. The length, diameter, stem diameter and tip "type" are what control what we use. Any good valve supplier (we use SI Valves, Simi Valley, Cal) can supply a valve that can "fit" in the oddest places. Manley and Ferrea are two other quality brands that come to mind.

Jim
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drobe2
Cochise

USA
333 Posts

Posted - 31 May 2007 :  8:06:54 PM  Show Profile  Reply with Quote
Thanks for the expert response. During 1969 I purchased the push rod and 1.65 rocker from a WDC area Pontiac dealer that raced a Judge at Aquasco Raceway in Md. They sold the rod and rocker as set. I used the set on a .30 over 400 running 067 heads and Mckeller #10, trips and 4:11s. I did not use the springs or valves because I was using Sig Erson springs. The rocker and rods made a notable difference in the feel of the motor. The thing about the dealer was, anytime you needed a Pontiac part, the parts man would always give you the Hi-performance part at the cost of the standard part. He was the driver of the Judge at the track. If my memory feeds me correctly, it was Sorensen Pontiac in Clinton,Md.

Having said all of that, I am thinking if it would be cost effective use the Ram Air set and if it would really make a difference?

What is the Wizzard.s major? what will he be doing?
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drobe2
Cochise

USA
333 Posts

Posted - 31 May 2007 :  10:56:36 PM  Show Profile  Reply with Quote
What do you think of this? dapa.org/members/tech_articles
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Mr. P-Body
Running Bear

USA
2244 Posts

Posted - 01 Jun 2007 :  08:38:55 AM  Show Profile  Visit Mr. P-Body's Homepage  Reply with Quote
Drobe,

Couldn't get to the link...

Son is a chemical engineering student. He's made it through the first half "with honors". We'll see how the rest goes...

The old McKellar grinds have very low lift. Definitely no need for the taller valves. That .408 lift, increased to .445 with the higher ratio rockers, would certainly show an improvement. Unless you're pressing the limit of the current springs, there's no need. Manley says springs should be as near "coil bind" as possible for the application, to reduce spring "surge". Having more length than you need is almost as "bad" as not having enough. Build to your application.

Jim
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