Quote:
Originally Posted by fielderLS3
Not necessarily. Example: Ford's 5.4L (OHC, 3-valve) engine makes less power than GM's 5.3L (OHV, 2-valve).
The 5.4L makes more low-torque, which shows that OHC and multi-valve doesn't necessarily have to be biased for high RPM power. A lot has to do with the intake, design of the heads, etc....The OHC design of the new Ford engines hasn't forced them to have peaky engines, they chose that because the lofty high RPM numbers sound good in an ad.
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The 5.4 3v was designed back in like 98. It also uses an abnormally long, over square rod length, specifically for towing and low-end torque output. Notice it makes more torque than the 5.3 (390 ft lbs vs what 340?)... If I'm not mistaken, they both make 320hp... If it had a more square short block and a valvetrain that could rev, it would make some great power from all that torque, but truck engines aren't made for that. It's still more efficient...notice the 390 ft lb's it is capable of... If built for performance instead of truck use, it would be right around as powerful as the 5.0. All of the things i'm saying are just extensions in reasoning from the fact that the OHC design is more efficient than the OHV design. I think we have argued about this before. I'm not saying OHC is better, because there are benefits to having a lighter, higher displacement lower-tech engine and that's all it's about is power to weight, but OHC is more efficient, you can't argue it.