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Head Flow & Power Calculator
Estimate horsepower potential from cylinder head airflow
Head flow potential estimates the horsepower a cylinder head can support from its measured intake airflow at 28 inches of water.
Formula: HP ≈ 0.257 × flow (cfm @ 28 in) × cylinders · Airflow demand = CID × RPM × VE ÷ 3456
What this number means
This estimates the horsepower an engine could support from cylinder head flow in CFM at a given lift, using the well-known flow-to-power relationship for naturally aspirated engines. It is a ceiling set by the heads, not a prediction for a mismatched combination.
What to change next
If the estimate is below your power goal, the heads — or the lift you are actually using — are the limit, and cam or intake changes alone will not fix it. If it is well above your current power, look to cam, intake and exhaust next.
Worked example
Heads flowing 280 CFM at 28 in of water suggest a potential of ≈ 575 hp in a well-matched naturally aspirated V8.