I've noticed that engines are rated at revolutions that are all over the map.

Example.. .the DOHC H22A is rated at 161 ft/pd torque at 5500 RPM.

The SOHC F22B1 is rated at 147 ft/pd at 4500 RPM.

How can one really compare engines when they are rated at diff revolutions?

Does the DOHC really make a big difference, or does it just give more head room (so you can shift at higher RPM)...?

 

Different engines are designed differently and therefore will generat power at different rpm. Typicaly, but not always, the dohc engines do make more power higher up in the rpm.

 

Now that I am thinking about it, I vaguely remember seeing some torque curve diagrams comparing two identical displacement engines by the same maker.. one with SOHC and one with DOHC.

IIRC, the DOHC torque curve continued to increase for about 2000 RPM beyond the drop off point of the SOHC engine.. I'll have to see if I can locate some diagrams.. unless anyone has similar?