and saab engines.. very easy to remove the chain and make them inoperable
and saab engines.. very easy to remove the chain and make them inoperable
From what I understand, the shaking common to flat crank engines does reduce engine life somewhat dramatically. When was the last time you saw a Ferrari with 100,000 miles? The main benefit, again, as I understand it, is to gain ease of making an exhaust system with the same efficiency as the bundle of snakes deal. I suppose that a well made bundle of snakes cross plane V8 would be nearly identical to a flat plane with regular headers.
This isn't meant to sound confrontational, but that's how it comes across. Really, I'm just interested.
Do you have any data to back up your reliability claims? Do V12 Ferrari engines last longer than their V8s? Do 4 cylinder engines without balance shafts fail sooner than those with balance shafts? I agree that excess vibration can cause failures, but does it cause failures in a Ferrari, and does it reduce engine life dramatically? It is commonplace to take the vibration into account and design parts to withstand it. Granted, Ferrari's engines aren't known for their reliability, but neither are their transmissions, or electronics.
I don't think it's vibration related engine failures that keep Ferrari owners from putting a lot of miles on their cars. I'm guessing a typical Ferrari owner probably has more than one car and the Ferrari just isn't practical enough for daily driving duties or family trips and that is why there are not a lot of Ferraris with 100,000 miles. If you're taking the kids to grandma's house, you can't take the 360.
Bob
Schmidlap wrote: This isn't meant to sound confrontational, but that's how it comes across. Really, I'm just interested. Do you have any data to back up your reliability claims? Do V12 Ferrari engines last longer than their V8s? Do 4 cylinder engines without balance shafts fail sooner than those with balance shafts? I agree that excess vibration can cause failures, but does it cause failures in a Ferrari, and does it reduce engine life dramatically? It is commonplace to take the vibration into account and design parts to withstand it. Granted, Ferrari's engines aren't known for their reliability, but neither are their transmissions, or electronics. I don't think it's vibration related engine failures that keep Ferrari owners from putting a lot of miles on their cars. I'm guessing a typical Ferrari owner probably has more than one car and the Ferrari just isn't practical enough for daily driving duties or family trips and that is why there are not a lot of Ferraris with 100,000 miles. If you're taking the kids to grandma's house, you can't take the 360. Bob
Bob, No real tech, but empirically, there is a reason that GM/Ford/Dodge everyone else doesn't make them like that. I would imagine that a flat plane crank would be a good deal cheaper and easier to design than a cross plane, which makes it even more likely that there is another reason for not using them. I've read a few articles on the subject of cylinder count and configuration, and durability is typically listed as a reason against flat plane stuff like that, but again, no real tech or firsthand experience.
-Brian
The reason for 90-degree crank V8s is NVH, plain and simple. The twit buying a Ferrari won't care that his car buzzes and vibrates because that is what "race" cars do. The guy buying a Ford to get back and forth to the store won't put up with that crap.
In reply to Knurled:
Thanks, that was a good explanation.
Knurled wrote: The reason for 90-degree crank V8s is NVH, plain and simple. The twit buying a Ferrari won't care that his car buzzes and vibrates because that is what "race" cars do. The guy buying a Ford to get back and forth to the store won't put up with that crap.
I don't know about that.
I suspect most new Ferrari owners would be far more irritated that the car didn't have Bluetooth then if it didn't have a flat plane crank.
https://www.youtube.com/embed/i-L9S_TDO9Y
Turbo flat plane 358 ci LS at 9k sounds funny
ACVWs have a flat plane crank.
They sound awful.
ACVW's are flat 4's, they always sound a bit off, the flat 6 is where the cool sounds are.
Trans_Maro said:ACVWs have a flat plane crank.
They sound awful.
As do Scoobies.
Chadeux said:Turbo flat plane 358 ci LS at 9k sounds funny
Is there some exotic metal that glows purple when it gets hot, or is it a side-effect of the type of camera used?
Trans_Maro said:ACVWs have a flat plane crank.
They sound awful.
they also have an odd every 4 revolutions shake that comes from their design.
In reply to GameboyRMH :
I think that is a camera related issue/feature.
Even the inconel exhaust I have worked with has a nice orange glow at temp.
My triple has a flat plane crank and I think they sound wonderful with a nice exhaust. Not so much with the stock muffler but the induction noises are great.
RichardSIA said:Made me realize that every other american V8 has a bad burble, like a dead cylinder.
Once you hear it, you can't un-hear it. Especially with a dual exhaust with no crossover.
Trans_Maro said:ACVWs have a flat plane crank.
They sound awful.
with a proper exhaust they do not sound bad. Same with Subarus. It's just hard to find a good exhaust
Ferraris rarely have 100k miles on them because people don't drive them enough. If I lived down south I'd DD a 360 and put 25k miles on it each year - which would improve the reliability by enough that it's probably cheaper than driving it 3k miles per year.
Most flat-plane-crank V8s do not have balance shafts. They are used in applications where power/weight or power/displacement matters more than NVH. It does improve NVH relative to a four-cylinder, because more firing impulses per revolution smooths out the drive and the second piston and rod on each crank throw can be used to cancel most out-of-plane forces.
I tried to get FCA Powertrain to develop a big (480-565 CID) flat-plane-crank V8 as a Viper V10/Hellcat V8S replacement when I was there but was unsuccessful.
chaparral said: I tried to get FCA Powertrain to develop a big (480-565 CID) flat-plane-crank V8 as a Viper V10/Hellcat V8S replacement when I was there but was unsuccessful.
I love you, man. 
So, my understanding is somewhat limited, but here goes:
Ducati builds 90 degree v-twins that have a common crank pin, and inherently perfect primary balance. Same thing with SV 650s, and maybe more. Is there a reason the same could not be true for each pair of cylinders in a V-8?
Interesting side note, Ducati solved the vibration issues on the SuperMono by making a dummy con rod connected to a linkage to cancel out vibration
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