tourqe differences.

[tranceokido]

I was just wondering if anyone knew why pushrod (OHV) engines create most of there tourqe downlow vs over head cam (OHC) do. Is it because they rely mostly on backpressure and big displacment. I was looking around on the internet and it really didn't say why or how it does..just that it does make most tourqe downlow.

[873.1]

i've heard a couple reasons. dont know if they're true though.
1. takes more effort to spin up the cams.
2. lacking vaccum required for low end torque??


PUSHRODS FOREVER BABY!!!! lol

[GPXSS]

Cam timing plays a big role, as well as if it has 2 valves or 4. 1 intake valve kinda restricts airflow, so they build the cam timing where it makes power down low. 2 intake valves are capable of sucking in huge amounts of air, so they set the cam timing to utilize this fact.

As the engine speeds up, the air is sucked in faster and faster, to a point where the air charge starts stacking, or ramming itself in. This is usually the kick crossover point youd feel on a DOHC engine (one without variable valve timing). This is where the engine is working in its effeciency spot and making the most power for its design.

Alternately, a pushrod 2 valve motor is more effecient down low due to the restrictions.