SBC flat-plane crank (barn find)
Race Director
Joined: Sep 2001
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From: NEwhere Ohio
Le Mans Master
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From: New Jersey
Not a huge fan of the sound either, personally think the gt350r sounds like an angry weed wacker...
And yes, aside from the cool factor it really doesn't do a damn thing powerwise. You can use headers to achieve evened pulses which about the only benefit because they tend to rattle themselves to death in larger displacements otherwise...
This guy is working on an awesome project and I did follow it a while back. It was cool.
And yes, aside from the cool factor it really doesn't do a damn thing powerwise. You can use headers to achieve evened pulses which about the only benefit because they tend to rattle themselves to death in larger displacements otherwise...
This guy is working on an awesome project and I did follow it a while back. It was cool.
Team Owner
Joined: Jan 2008
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From: chicago
probably an old ''smokey yunick'' trick
https://www.carthrottle.com/post/7-h...rk-of-one-man/
this guy once built a 7/8's scale 66-67 chevelle to run nascar
https://www.carthrottle.com/post/7-h...rk-of-one-man/
this guy once built a 7/8's scale 66-67 chevelle to run nascar
Team Owner
Joined: Aug 2004
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From: Park City Utah
A SBC w/a flat plane sounds like a 4 cylinder. Not a Ferrari.
Far greater gains could be realized for less money with an flex plate "flywheel" and a multi disk clutch,
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Le Mans Master
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From: New Jersey
Melting Slicks
Joined: Nov 2013
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From: Greater Cincinnati Area.
So, if the flat architecture is so much better.. Why isn't everyone using it?
Surely there must be some serious drawbacks somewhere?
Surely there must be some serious drawbacks somewhere?
Last edited by confab; Apr 23, 2019 at 01:31 PM.
Le Mans Master
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From: New Jersey
Racer
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From: PA
Melting Slicks
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From: Greater Cincinnati Area.
So, I guess this is good is you have a peaky, freaky, little 12 cylinder with pistons the size of insulin syringes..
But not so good if you have a giant bore and great big rods?
But not so good if you have a giant bore and great big rods?
Le Mans Master
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From: New Jersey
No it does, you build an engine that can supposedly rev that high but can't. One knocked the bearing right out of it without anything going wrong otherwise. It's great for small displacement... not so much on bigger ones.
Racer
Joined: Sep 2017
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From: Marianna Fl
Personally If I was building a track car I would give a flat plane crank a shot for a SBC or LS mainly for an increase in rev speed and to do something different. For a street car the tried and true cross plane we use is just fine for me. I give this guy a lot of credit for trying something most would just scoff at. To my understanding the original v8's from the 30s and 40's where mainly flat plane but the idea was droped, anyone know why? I wonder if it was to mitigate vibration or if they found torque with the change in firing pattern.
Team Owner
Joined: Aug 2004
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From: Park City Utah
They didn't know better
It was cheaper
Virtually no cars had crank counterweights at that time anyway
All motors vibrated quite a bit.
They went to a crossplane crank b/c it balanced out w/counterweights smoothly, and the flat plane didn't.
The '32 Ford "flathead V8" had a cross plane crank -an example of a '30's, CHEAP V8 that used the cross plane, showing that it was common design feature, by then.
.
Last edited by Tom400CFI; Apr 23, 2019 at 05:18 PM.
Racer
Joined: Sep 2017
Posts: 452
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From: Marianna Fl
Most modern examples of a flat plane crank engine are internally balanced and require less mass providing a quicker rev (throttle response) but no higher rpm. Like I said I'd so it for the sake of doing it not to expect any marvelous gains.