351 Horse Power & Tourqe Confusion

[bowturkey]

Looking at horse power & tourqe over all the years it gets pretty confusing at least to me. Differnt years they rate them at differnt rpms so how do you compare from apples to apples when you are tring to build an engine?
(1984-92 sae net) 200@3800 rpm
(1982-83 sae net) 180@3600rpm
(1981-sae net )140@3400rpm
how do you sort it all out?

 

[Psychopete]

The RPMs are going to variate because the max horsepower that it was rated at. The first one for example (no torque?), is indicating that the 84-92 made a max of 200hp and it was spinning ~3,800 RPM at that horsepower rating. How true those figures are or not, I am not entirely sure.

How it's built can completely change how much power is output and where. That's just a "summary" based on bone stock engines. Seeing the actual curves between the 3 would give a much broader picture for comparison.

Pete

 

[Twizzler09]

The motors are rated differently through the years because of changes in "stock" engine design. Essentially they are the same motor, just with minor top-end changes that changed power output.

If your looking to put a completely stock 351 from a certain period into your truck, then compare power curves. Find the one that would most suit your needs.

If your looking to "build" the motor for a specific purpose, it probably wont matter which one you choose, because in the end they'd end up putting out very similar power, if not precisely the same.