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Hello all,
I have a question about my friend's car. I have it all apart, (heads and manifolds) due to bent valves because of the dowel pin backing out of the cam sprocket. Anyway It has a 600 cfm Holley single pumper, vac secondarys, and a Offenhauser Port-O-Sonic manifold. Just wondering about how much HP this is producing with stock pistons and cam? However I am thinking it has a high lift cam as the pistons tapped all the intake valves when the cam got out of time. It is on a 63 Galaxie 500XL, I am assuming original engine. Any Hot Rodders out there? Thanks, Kim
 

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Hello all,
I have a question about my friend's car. I have it all apart, (heads and manifolds) due to bent valves because of the dowel pin backing out of the cam sprocket. Anyway It has a 600 cfm Holley single pumper, vac secondarys, and a Offenhauser Port-O-Sonic manifold. Just wondering about how much HP this is producing with stock pistons and cam? However I am thinking it has a high lift cam as the pistons tapped all the intake valves when the cam got out of time. It is on a 63 Galaxie 500XL, I am assuming original engine. Any Hot Rodders out there? Thanks, Kim
I don't have Jay Brown's book in front of me, but I don't think that intake was a great performer. On top of that, the single plane design is more for top end flow and usually kills the torque down low. About the only thing that is gained by using that intake for his application is that the front of the car is about 40 lbs lighter.
 

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I also don't have Jays book in front of me, but I was thinking that he found the Port O Sonic to be a very poor performer. Agreed though, use it for the weight savings.
 

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I don't have Jay Brown's book in front of me, but I don't think that intake was a great performer. On top of that, the single plane design is more for top end flow and usually kills the torque down low. About the only thing that is gained by using that intake for his application is that the front of the car is about 40 lbs lighter.
I don't think the offy was a great performer either but I think the intake that impressed the most as an all around performer was a streetmaster.. It is actually a single plane intake..
 

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I don't think the offy was a great performer either but I think the intake that impressed the most as an all around performer was a streetmaster.. It is actually a single plane intake..

The Streetmaster is definitely the exception to the rule, and indeed a great intake.
 

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I don't have Jay Brown's book in front of me, but I don't think that intake was a great performer. On top of that, the single plane design is more for top end flow and usually kills the torque down low. About the only thing that is gained by using that intake for his application is that the front of the car is about 40 lbs lighter.
Went and checked the test results. The stock C4 cast iron intake actually made move average HP than the Offy, although it gave up a few at peak. On the torque side, the cast iron C4 was far greater than the Offy, with the Offy being pretty close to the bottom in both average and peak. All of these came from his 410 HP 428 CJ test engine.

In a heavy Galaxie I think the torque is much more important to look at than the HP numbers. Rarely is a car like that pushed anywhere near the peak rpm, but usually driven in the heart of the torque curve.
 
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