Am I Going To Be Happy With This Camshaft?

[Bewy]

I would use the cam in post #47.

 

[Bodyperson]

I would use the cam in post #47.

I get it with the headers. I always understood the asymmetrical profiles were for factory manifold cars. I can real back my order but I think we are splitting hairs at this point.

 

[Garrett Ellison]

It’s more to do with the 108 LSA than the dual pattern grind. It would perform stronger across the entire rpm range.

 

[RustyRatRod]

I get it with the headers. I always understood the asymmetrical profiles were for factory manifold cars. I can real back my order but I think we are splitting hairs at this point.

You would be correct. There's nothing written in stone that says a split pattern is best for manifolds and single pattern best for headers. That's an unknown that cannot be known until you hit the street, drag strip or dyno. And yes, it's splittin hairs. I wouldn't sweat it a bit.

 

[Bodyperson]

I'm just trying to soften up up the hit on the low end. Pump gas for me. 93 these days.

 

[Dale Davies]

Cam And Lifter Kit [CL390171] - $603.00 : ISKY Racing Cams, Do It Right

• 
  Hyd.67
• Valve Lift Int/Ext. 0.465
• Valve Lash Hot Int/Ext. 0.000
• ADV Duration Int/Ext. 270
• 0.050 Duration Int/Ext. 221
• Lobe Center 108

I was going to use a (used) similar cam in a blueprinted 340 I am building but one lobe is a little shy of specification .005 to be exact. The corresponding lifter had not been spinning. It has a decent groove in it's face. The 340 is at 4.100 bore now. I Liked the old cam but things have changed on the engine.
Promaxx shocker 170 cfm heads and PRW stainless roller rockers. 1:6 as per B3RE suggested along with his correction kit. I read PBR's write up about these heads and I see that not much flow increases between .450 and .500 lift.
Is it a safe assumption that lift beyond these numbers is a waste if not undesirable? I realize there is more to it than just lift. I'm running 3.91 gears. Auto (904 or 727) with stock converter hopefully. Funds are running low. 67 Barracuda at basically stock weight. I have Doug headers and late model 340 manifolds. My intake options are basically stock manifolds. My best available option is the aluminum Mopar stock replacement square bore with a 600 cfm double pumper. I'm willing to step things up but its just going to be a grocery getter that blows a few doors off on the way.
I am not trying so set the world on fire. I just want to have some spirited driving.

The 0.465" lift spec is I take it with 1.5:1 rockers. With 1.6:1 rockers your lift will be about 0.495". Depending on compression and intake valve diameter are, it should work out fairly well for a street engine with some grunt.
270 - 180 = 90
90 ÷ 2 = 45° overlap
That is in the middle for hot street use. Should be a bit of lope but not bad.

 

[Dale Davies]

You would be correct. There's nothing written in stone that says a split pattern is best for manifolds and single pattern best for headers. That's an unknown that cannot be known until you hit the street, drag strip or dyno. And yes, it's splittin hairs. I wouldn't sweat it a bit.

Dual pattern usually have more duration on the exhaust to compensate for a restrictive exhaust, whether from port design or the manifolds. Frequently have less lift as that is not a big problem on the exhaust.
With good exhaust ports and headers a single pattern tends to provide a bit more low speed to mid range torque.
You are correct Rusty, kind of splitting hairs.

 

[RustyRatRod]

Dual pattern usually have more duration on the exhaust to compensate for a restrictive exhaust, whether from port design or the manifolds. Frequently have less lift as that is not a big problem on the exhaust.
With good exhaust ports and headers a single pattern tends to provide a bit more low speed to mid range torque.
You are correct Rusty, kind of splitting hairs.

These days though, a lot of them have more lift and duration on the intake side. I've never been convinced that works as well and Doug Dutra proved it did not with the slant 6.