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Discussion Starter #1
Why hasn’t Maserati done this yet? Is it cost....and a myriad of other things? The MC12 has the flat plane V12 but we all know that’s the V12 from the Enzo....

I was just curious...that’s all.

Kindly,
Stephen
 
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Pretty simple explanation...Flat plane engines vibrate a lot...In a Maserati it would be probably be unacceptable...Sit it a Ferrari California(flat plane)compared to a Granturismo(cross plane)...The Ferrari shakes the crap out of you..Big reason is the exhaust...In a flat plane you are treating each half of the engine as basically two four cylinder engines based on the firing order compared to say a Chevy 350..In a rear engine car you can design the exhaust so much better and not be hurt by cramped engine compartment of a Maserati...Google images of Ferrari 430 engines and look at the headers...The flat plane crank it what gives a Ferrari its distinctive sound BTW...A must GT350 Mustang also has a flat plane crank...Pull up a Youtube video and listen to one of those...A California is front engine and flatplane, but it is really a compromise....Hope that helps...Jason
 

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Discussion Starter #3
Hi Jason,

That makes sense. Flat plane engines also rev faster and higher as well right or just faster????

Kindly,
Stephen
 
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They just generally have better designed intakes and exhaust systems on them and are more high performance orientated ...Therefore they are also setup to operate up higher in the higher rev ranges to take advantage of the free breathing nature....A GT 350 Mustang turns like 8300 RPMs..A Mustang!..I know folks on here think a Granturisomo engine is like a 430 Ferrari..It has some similar components, but if you heard both run you would hear the difference...The 430 engine is like a race engine in a street car.. Look how straight the intake runners are and the exhaust manifold doesn't have the tight bends...Plus 2 throttle bodies, dual VVT, etc...There are some excellent videos about it on Youtube and I intentionally left out a bunch of stuff about cylinder scavenging etc..to keep it simple..Jason
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Jason would you say the vibration contributes to the common problem of the Ferrari F430 manifolds cracking?
 

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+1 on Jason's reply. 90deg V8's have some really nasty 2nd and 3rd order harmonics, that are damped somewhat by a 2 plane crank. A flat or 180deg crank has to be very carefully designed to keep it from trashing bearings, cams, even valve springs. Ferrari had a recall on 430 cranks years ago possibly due to flat design. On the old 308 series gilmer belt engines, the rubber belt actually worked as a harmonic damper. Having built racing flat plane V8's I don't really see an advantage other than sound, for a flat plane engine. Modern metallurgy and CAD make 90deg. cranks almost as light as a 180deg ones. I've got a BBC crank in my Corvette that weighs less than 42lbs.
 
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The advantage is better breathing or technically volumetric efficiency through scavenging...Your basically running two 4 cylinders and the exhaust pulses on each bank are sequential for those 4 cylinders rather than go from bank to bank...You can design your engine with exactly with the same length intake to exhaust collector length...The downside is the vibration and the larger you make the engine the worse it gets...Don't notice it much on a 3 liter 308, but it is fairly noticeable on a 430....Jason
 

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Hey Jason, it's nice to converse with someone who gets engine theory. You are correct that engine size makes a difference, when I built that BBC, Crower flatly refused to build me a 180deg crank (pun). But I think for the 430 it is a matter of chain driven cams. Cosworth had problems with the early DFVs because the cam drive gears would transmit the resonance from the crank to the valve train and it literally could shatter the springs. The high idle speed kept the engine out of some of the destructive resonance. I know that our back and forth discussion on this is a bit much for some people, but I have seen past posts on the notion of putting a 430 crank (and cams) in a F136r engine, and I thought an explanation of why that is not a practical idea, nor really an advantage for the tightly packaged front engine of a 4200, was in order. You have worked on a lot of engines, as have I, and you may agree with me that, for it's purpose, in terms of useful torque, good horsepower, and longevity, the F136r is hard to beat. Ed.
 
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Yeah, I'm engine guy and that is my favorite part of an automobile.. Not a fan at all of these electric cars..
I have seen the kits for SBC to convert them to a flat crank and they sound cool..I can only imagine the vibrations in a BBC..Jason
 

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Don't forget the counterbalance architecture differences. I understood that this was a major contributor to flat plane vibrations as the cross plane can be completely isolated with the flexibility of the added weights.

Also with less collective counterbalance weight, there is far less centrifugal force at the crank allowing for more responsive revs and higher limits on the same engine design (F136R/S vs E). The same issues with conversion of rotated energy can be seen when revving a DS against an Automatica. The automatica has to convert the weight of the transmission's neutral gear vs the DS, which is completely separated from the flywheel when in neutral. The Automatica falls slowly down to idle while the DS drops like a rock (how I like it).
 
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Yes, the flat plane crank is lighter, but the added weight of the cross plane has another benefit other than vibration...Here is the problem in a street car...That heavy weight spinning around at 800-1000 RPMs at idle is kinetic energy...It is what helps clutch engagement at low RPMs and dampens the A/C compressor coming on...That is why you pretty much don't see many street cars coming with an aluminum flywheel from the factory...Fine on track car
 

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Discussion Starter #14
Hi guys, so I listened to the Mustang GT350 and honestly...I think it sounds awful..doesn’t fit the character of the car. I’ve never been a fan of the car...but to each his own.

Kindly,
Stephen
 
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See, I like the way that car sounds..It is just a big motor with a flat plane so the sound is different than a Ferrari...Love the Coyote engine family...BTW...That car vibrates a lot at idle...They didn't show you that....lol....Jason
 

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Discussion Starter #16
Good point...I guess I am not used to a pony car sounding like that....I hear the Coyote is pretty bullet proof!
 

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You would love my Corvette then Jason, 4.5" bore, 3.66" stroke 10k redline and 180deg headers (couldn't have the crank, crossed 4 tubes under drysump pan), Crower- MacKay Lucas stack injection. Makes your hair stand on end. But after huge$ and huge hp I found that you actually could have too much power. It's an old SCCA A/SR race car made street legal. Gotta love North Carolina.
 

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Ok, I have stepped in it now, I'll look like a one delta ten tango if I can't get pix to load. It worked.
#1 engine. DSC01611.JPG DSC01604.JPG DSC01597.JPG DSC01600.JPG DSC01619.JPG #2 is rear suspension, #3 piston weight #4 Titanium connecting rod is lighter than piston #5 is front suspension.
 
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