There is more to making horsepower than cylinder head flow. That can’t be emphasized enough.

 

"...in order to GO, you must FLOW"...where did that come from? I think head flow is the foundation that which all power is built upon.

 

Depends on the rest of the build.

The issue is, it doesn't matter how you build the bottom, if the heads won't flow, you're not going to make the power without an adder. If the heads flow but them bottom end isn't built to make power, well, you make more than stock but not full potential.

The engine needs to move fluids/gasses in and out. That's where the flow comes into play.

 

The flip side is how effective you are in;

1; Making the most power out of what you have.
2; How effective you are in utilizing that power to go fast.

 

Shape is more important than flow. All day long. A quiet port that doesn’t flow well in reverse is better than a noisy port that flows 85% in reverse.

 

• flow at low lift is important
• matching the rest of the car to the engine is important
• having the car "work" in itself is huge.

My point is, a well sorted out 385 hp powered Duster can beat a 485 hp powered Duster if the 385 mule is in a car that is well sorted out.

 

Bingo dead on.
Exactly what I was saying above.

 

Point one is not what my experience says. For more than one reason. I look at the numbers below about .200 lift, but unless something is way wrong I don’t care about that.

If you can test low lift at say...100 inches of water you’d see why the low lift numbers don’t mean much at 28 inches. Plus, the piston is in the way. Plus, you have to deal with cross flow at overlap. To fix that you have to reduce overlap and that’s a power killer.

 

I should have said what I meant at low lift. .400

 

With a 150 shot 500 hp should not be difficult to hit with magnum heads.

 

Listen, comparing flow numbers you found on the internet is like writing food reviews by reading the menu.

#1 no two flow benches are the same.
#2 no two operators are the same.
#3 no two weather conditions are the same, and this matters because flow machines do not suck, they cause atmospheric pressure to blow.

Notice I didn't even get into heads, valves, cam dynamics, etc. If you're reading flow numbers on the internet trying to decide what heads are best, you're not driving at a level that it will matter.

 

Horsepower on a nitrous boosted motor at the kind of power level you're talking about is primarily affected by nitrous jetting. The Magnum head has a decent exhaust side which will help accommodate the nitrous. Head flow becomes a little less critical factor when injecting torque from a bottle. I personally wouldn't spend a lot of time on a set of Magnum heads unless you just love them. if you're going to upgrade then step up. But that being said 500 horse range is definitely achievable with Magnum heads on the juice.

 

Just for comparison my 470 stroker Dynoe’d at 655 hp. Heads flow 320 cfm. I believe the formula is 2.06 hp per cfm. Mine is actually pretty dam close. Volumetric efficiency was 108%. I will add that some motors put out beyond expectations while others fall short. I can’t stress cylinder prep enough. Having straight round bores is an absolute must. Kim