Hmmm,
Not to be too picky, but OHC engines are OLDER tech than the pushrod engine, IIRC.
There are advantages and disadvantages to each. A pushrod engine is great packaging. The Duratec is a great engine, but takes up a lot of space for the displacement.
Maybe some of our Ford engineers can chime in on this one. What is the package size of a 2.5L or 3.0L Duratec compared to say a 4.6L SOHC Ford V8, or even compare the 3.0L Duratec package to the 3.0L Vulcan package.
The other thing is that with DOHC, you put more weight at the top of the engine. Having the weight at the bottom helps with handling.
Sure, GM and others could make their engines out of all aluminum and reduce the weight quite a bit.
Are there any aluminum pushrod engines in production? Maybe there are some issues with an 'all aluminum' pushrod engine. (We know that they really are not 'all aluminum' right, lest anyone start sniping here.)
Say what you will about the 3.8L GM V6, I had one in the 87 Buick and it was a pretty nice engine. That 3500+ pound car averaged about 24MPG in urban commuter driving at speeds typically 75+ MPH, and achieved over 31MPG in one highway trip, but typically got 27-28 on the highway at about 70MPH.
Heck, my 95 T-Bird (4.6L V8) is averaging about 22, with highway economy of over 26 on a recent trip to Ft. Worth, TX.
Americans buy torque, that is pure and simple. Look at how many buy SUV's. It's not just the size, they have big torquey engines.
You want handling and an aluminum engine, buy a Honda S2000, Mazda Miata, or Toyota MR2, maybe even a Nissan 350Z.
Oh, and to answer my own question, I guess there is an aluminum pushrod engine, I believe you can get one of those in a Corvette.
FWIW,
TB
