Flat crank engine
Melting Slicks
Joined: Nov 2012
Posts: 3,161
Likes: 686
From: SUFFIELD CONNECTICUT
Ford's marketing department. Ford turned “flat-plane crank” into a sexy catch phrase that sounds really impressive to people who know absolutely nothing about engines. Everyone’s talking about the GT350’s flat-plane crank, and you got to hand it to Ford for pulling off one heck of a PR coups that transformed the entire automotive press corps into a flat-plane crank propaganda machine.
Ford designed some badass CNC-ported cylinder heads for the new 5.2L, but no one’s talking about that. Ford designed the F1-inspired roller finger follower DOHC valvetrain that makes OE pushrod motors look stupid, but no one’s talking about that. The camshaft profiles and a variable valve-timing strategy that—when combined with the phenomenal low-lift airflow of the 5.2L’s four-valve cylinder heads enables it to produce 24% more torque per cubic inch than GM’s 7.0L LS7 (1.36 vs. 1.10), but no one’s talking about that. All of these factors play a far more substantial role in both the 5.2L’s specific output and high-rpm capability than its flat-plane crank, but no one’s talking about that.
Ford designed some badass CNC-ported cylinder heads for the new 5.2L, but no one’s talking about that. Ford designed the F1-inspired roller finger follower DOHC valvetrain that makes OE pushrod motors look stupid, but no one’s talking about that. The camshaft profiles and a variable valve-timing strategy that—when combined with the phenomenal low-lift airflow of the 5.2L’s four-valve cylinder heads enables it to produce 24% more torque per cubic inch than GM’s 7.0L LS7 (1.36 vs. 1.10), but no one’s talking about that. All of these factors play a far more substantial role in both the 5.2L’s specific output and high-rpm capability than its flat-plane crank, but no one’s talking about that.
Safety Car
Joined: Nov 2002
Posts: 4,168
Likes: 1,336
From: FLL Florida
And none of the Ford engines discussed above have the sweet delicious torgue of the old fashioned 2 valve pushrod GM engines that makes the driving pleasure for 90 % of what the cars are used for ....on the street. But they do rev to the moon and are efficient making horsepower per cubic inch. Let me drive a LS or LT NA V8 anyday.
Safety Car
Joined: Nov 2002
Posts: 4,168
Likes: 1,336
From: FLL Florida
And didn't Ford stray away from the standard "flat crank" design in terms of firing order? I haven't found hard evidence (such as firing order combined with Ford's cylinder numbering versus say Ferrari's), but I've read that several times. Makes me wonder if that is the reason for the issues.
Melting Slicks
Joined: Apr 2018
Posts: 2,666
Likes: 1,778
From: North Texas
I guess it depends. Trying to find the link right now, but it said something about Ford going with a different firing order in order to change the sound. The way the article made it sound, it was a very un-natural (for a flat plane v8) to have that particular firing order and seemed to suggest that could be part of the reason for the issues.
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Joined: Jan 2020
Posts: 59
Likes: 26
And none of the Ford engines discussed above have the sweet delicious torgue of the old fashioned 2 valve pushrod GM engines that makes the driving pleasure for 90 % of what the cars are used for ....on the street. But they do rev to the moon and are efficient making horsepower per cubic inch. Let me drive a LS or LT NA V8 anyday.
