Hi-PO Stang
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FPC FTW !
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Aaaaaaaaaand :chill:
C'mon gents, I know the lack of info/spyshots is frustrating, but lets keep it civil
C'mon gents, I know the lack of info/spyshots is frustrating, but lets keep it civil
machsmith
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No thanks, I got that and I hope the thing gets to 40,000 miles.
nastang87xx
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The 488 is a 180 crank too isn't it?
It's all about the compression ratio, the cylinders, and the rods, not the crank.
DrumReaper
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The crank has as much to do with the stroke, does it not?... which is why a FPC makes less torque than a CPC... right?
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Grimace427
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I've yet to see any compelling evidence that the crank arrangement has anything to do with torque production. The primary reason the FPC's put into production today have a more peaky power production is because that is the way they were tuned. Things like their intake manifold and camshaft design put their power production up high in the powerband, same as it would with a CPC crank. Ask anyone with a Boss or similar intake manifold or aggressive cams on their Coyote where the low-end torque went.
Likewise if you wanted to make a torquey FPC engine I bet you very well could, but you'd be giving up the main advantages of the lighter crank and be adding unnecessary vibrations.
Darkane
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Right. Reduction in stroke will reduce secondary vibrations in FPC configurations.
This is part of the reason of "smaller" displacement engines but big bores and physical dimensions.
nastang87xx
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I think there's entirely way too many variables to be so sure footed to say "yes, ALL FPC engines are terrible with low end torque" or whatever it may be.
DrumReaper
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I don't think anyone here said that... it's a known fact that the shorter stroke with FPCs allow for higher RPMs and lower torque values than CPCs as CPCs usually have a longer stroke.
Look it up...
Look it up...
Hi-PO Stang
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The Ford engineers know what they are doing. If they want to supercharge a big inch FPC V8, they will make it durable and fast.
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Darkane
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No. FPC have the highest specific tq/L of the NA setups. It's just made higher in engine speed.
CPC may have a broader curve down low, but average torque across the band of engine speed will be higher in the higher volumetric efficient engine: FPC.
DrumReaper
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"Most flat plane crankshafts have a shorter stroke than crossplane designs. That means less crankcase space is required; however, shorter strokes often lead to lower torque output.
The Bottom Line
Crossplane Crankshaft Advantages: Smooth, vibration-free performance; distinctive American muscle car burble.
Crossplane Crankshaft Disadvantages: Heavier (harder to rev), requires larger crankcase.
Flat Plane Crankshaft Advantages: Lighter, more compact, more responsive (high-revving), better exhaust scavenging.
Flat Plane Crankshaft Disadvantages: Prone to vibration, lower torque levels."
http://www.onallcylinders.com/2015/01/15/cross-plane-vs-flat-plane-crankshafts/
Hmmm... I guess these guys are wrong just like me, and the other articles and discussions on FPCs that all say the same thing.
The Bottom Line
Crossplane Crankshaft Advantages: Smooth, vibration-free performance; distinctive American muscle car burble.
Crossplane Crankshaft Disadvantages: Heavier (harder to rev), requires larger crankcase.
Flat Plane Crankshaft Advantages: Lighter, more compact, more responsive (high-revving), better exhaust scavenging.
Flat Plane Crankshaft Disadvantages: Prone to vibration, lower torque levels."
http://www.onallcylinders.com/2015/01/15/cross-plane-vs-flat-plane-crankshafts/
Hmmm... I guess these guys are wrong just like me, and the other articles and discussions on FPCs that all say the same thing.
Darkane
Well-Known Member
I read that. It appears you're fishing for evidence to support your opinion instead of taking my facts.
I won't further press the issue, just do some research on production NA engines (specifically V8) and come back and post what the highest specific tq/L engine is.
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DrumReaper
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"WHERE IS THE TORQUE?!
One of the first things people notice when comparing engine styles is that flat plane V8s typically don't make as much torque as an american V8. Now although this is somewhat controversial, there is a good reason that most don't make the same torque. Typically these engines are in exotic supercars that rev to the moon. The motors are tiny with a short stroke to aid in high rpm abilities. Now, if you ever paid attention in science class as a kid, or if you've used a breaker bar, you will understand that more leverage means more turning force(torque). The same logic applies to a motor. A longer stroke will aid in more torque, and the tiny cross planes typically have very short strokes. While this is not the only factor, it is too complicated to point at one cause, but a flat-plane can make just as much torque as a cross plane, it comes down to how the engineers design it, and how much torque they want to give up for higher rpm capabilities."
https://www.*******************/forums/threads/the-flat-plane-crank-explained.973784/
Dude, I can keep this up all day. Just admit your "facts" are really your opinions. I'm not fishing either. This info is everywhere.
One of the first things people notice when comparing engine styles is that flat plane V8s typically don't make as much torque as an american V8. Now although this is somewhat controversial, there is a good reason that most don't make the same torque. Typically these engines are in exotic supercars that rev to the moon. The motors are tiny with a short stroke to aid in high rpm abilities. Now, if you ever paid attention in science class as a kid, or if you've used a breaker bar, you will understand that more leverage means more turning force(torque). The same logic applies to a motor. A longer stroke will aid in more torque, and the tiny cross planes typically have very short strokes. While this is not the only factor, it is too complicated to point at one cause, but a flat-plane can make just as much torque as a cross plane, it comes down to how the engineers design it, and how much torque they want to give up for higher rpm capabilities."
https://www.*******************/forums/threads/the-flat-plane-crank-explained.973784/
Dude, I can keep this up all day. Just admit your "facts" are really your opinions. I'm not fishing either. This info is everywhere.
Darkane
Well-Known Member
Hahaha. Do you read what you post? That's riddled with spelling errors and mistakes. In fact he confuses the cross plane and flat plane here:
"Tiny cross planes typically have very short strokes"
He meant flat planes. I love this one:
"A flat plane can make just as much torque as a cross plane".
Anyway the 4.5L in the Italia is the specific torque/L champion. FPC.
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