Why is DOHC better than Pushrod?

I’ve asked this before, and none of you gave me a good answer. Chevy’s smallblock V8's are ALWAYS the exception, without fail. There literally isn’t a single objective benefit to DOHC over a chevy smallblock. I’m not trying to be an asshole, I’m genuinely confused, and haven’t received a compelling answer in the past.


Anyway, let’s compare my Corvette’s 6.2L V8 to the E92 M3’s 4.0L V8:

Size: The “massive” 6.2L LS3 is physically smaller and lighter and has a lower center of gravity than the “tiny” 4.0L S65, hence why an LS-swap is so cliche; it’s the only thing that will fit in a cramped engine bay.

Power: While both engines make similar horsepower, the LS3 makes 43% more torque (Corvette: 430hp/424lb-ft, versus BMW: 414hp/295lb-ft).

Efficiency: My Corvette gets WAY better fuel economy, especially on the highway (16/25mpg Corvette, 14/20mpg M3). In the real world, I routinely get 27 highway.


Reliability: The LS3 is one of the most legendarily reliable V8’s on the market, and the go-to crate engine. The S65 is a notorious maintenance nightmare.

Redline: Ok, you got me here, pushrods don’t rev too well.

Am I missing something here? What’s the point of having a higher redline if you have to compromise size, weight, COG, torque, efficiency and reliability? Are Chevy’s smallblock pushrod engines some sort of statistical anomaly? 


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