Bentley Mulsanne - 6.75L Twin Turbo Pushrod V8
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From: Jupiter, FL
Bentley Mulsanne - 6.75L Twin Turbo Pushrod V8
505hp 752lbft.
Even Bentley recognizes that you cant beat the good ole pushrod for low end torque.
http://www.autoblog.com/2009/09/15/f...f-torque-at-1/
Even Bentley recognizes that you cant beat the good ole pushrod for low end torque.
http://www.autoblog.com/2009/09/15/f...f-torque-at-1/
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Oops, didn't realize that. I heard it from somewhere else. This mentions it though:
http://www.motortrend.com/roadtests/...ook/index.html
http://www.motortrend.com/roadtests/...ook/index.html
Last edited by ImportedRoomate; Sep 17, 2009 at 03:16 PM.
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From: Memphis
The roots of that engine have been around since the late 60s so I'm not surprised at all that it's a pushrod... back then pushrods were pretty common luxury vehicles. I guess it's still impressive that the basic design has been found to be sustainable for this long, though. According to wiki the only longer-standing engine series is the SBC.
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So, the world's most prestigious automobile uses a pushrod engine, and here we are on this board lamenting that GM needs to put "high-feature" engines in its luxury/performance brands to be taken seriously... 
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From: Okemos, MI
Low-end torque comes from displacement (and appropriate use of said displacement, of course). I refer you to the Bugatti Veyron as an example of a high-displacement, high-torque OHC motor.
The reason you don't find many torquey OHC motors is twofold. One, OHC takes up more space in an engine bay, so they tend to make the motor smaller to compensate.
Two, OHC is more conducive to high RPMs. High RPM is a great way to make power, especially in an engine that is short on torque in the low and mid RPM range. This generally results in camshaft designs that are biased towards higher RPMs, which in turn hurts low-end torque. Modern OHC engines usually have variable valve timing, which helps this to some extent, but the point still stands.
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From: SeVa
Pushrod vs. DOHC has nothing (directly) to do with low-end torque.
Low-end torque comes from displacement (and appropriate use of said displacement, of course). I refer you to the Bugatti Veyron as an example of a high-displacement, high-torque OHC motor.
The reason you don't find many torquey OHC motors is twofold. One, OHC takes up more space in an engine bay, so they tend to make the motor smaller to compensate.
Two, OHC is more conducive to high RPMs. High RPM is a great way to make power, especially in an engine that is short on torque in the low and mid RPM range. This generally results in camshaft designs that are biased towards higher RPMs, which in turn hurts low-end torque. Modern OHC engines usually have variable valve timing, which helps this to some extent, but the point still stands.
Low-end torque comes from displacement (and appropriate use of said displacement, of course). I refer you to the Bugatti Veyron as an example of a high-displacement, high-torque OHC motor.
The reason you don't find many torquey OHC motors is twofold. One, OHC takes up more space in an engine bay, so they tend to make the motor smaller to compensate.
Two, OHC is more conducive to high RPMs. High RPM is a great way to make power, especially in an engine that is short on torque in the low and mid RPM range. This generally results in camshaft designs that are biased towards higher RPMs, which in turn hurts low-end torque. Modern OHC engines usually have variable valve timing, which helps this to some extent, but the point still stands.
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