Quote:
Originally Posted by IamBatman
and what good reason would that be? (other then engine complexity snobbery)
the only advantages of a DOHC over a modern pushrod engine is high RPM smoothness... and the LS-series V8s are so good at low RPMs that you hardly ever need to rev it up high.
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It's not just snobbery.
Don't get me wrong, - I admire the LS series V8s. They're light, compact, torquey and produce good power. They're also simple, easy to work on, and have any number of aftermarket components available for enhancing their performance still further.
All else being equal though, a pushrod engine has to have compromises in its head/port design (because of the pushrods) which will affect performance, and it will also have greater reciprocating mass which affects maximum revs and therefore power output.
Some of these deficiencies can be addressed with better engineered components, but these can be quite expensive, thereby negating the initial cost advantage of the pushrod engine.
Finally, because of the compromises in head design and valve-train actuation inherent in a pushrod engine, meeting increasingly stringent emissions targets is likely to be more difficult than with a DOHC motor.
I think it's horses-for-courses. If you wants lots of torque low in the rev-range for towing or motivating a heavy vehicle, - then the LS series is a great motor.
If you want better volumetric efficiency, smoother operation, higher rev-limits and more power, then a quad-cam V8 or V10 of similar capacity is probably a better solution.
For the new Esprit, I think the Lexus V10 is likely to be more in-keeping with the character of the vehicle.