Flat Plane Crank

[tpxomaha24]

So I went to the Historic Races here in California at Laguna Seca. This year they celebrated the GT350 they had a huge tent with a couple new GT350's and a R model, plus various stations on the diffrent components that are new to the vehicle. They also did some laps on the track and man do they sound amazing in person ! I'm wondering what would it take to make a kit to put a flat plane crank in one of our Cobra's ? Like a stroker kit but with all components needed like cams and the obviously needed custom tune . Just thought Id throw it out here im sure there are a few of u out there that gave thought to the benefits to it! It sure sounds good !

 

[Nightmare302]

I don't think you understand what a flatplane crank and cross-plane crank are. There is no way you can fit a flat plane crank into a 4.6 motor.

*Edit: I suppose in theory if you had enough money you could make anything work.

 

[tpxomaha24]

Well I Thats why asked just wondering I saw the crank on the bench they had no block set up so I just was wondering how it would and if it would work. Thanks for the feed back.

 

[Svtmustang01]

Even if you could Im not for sure you would want one. As of right now im not convinced on a flat plane crank. There is a reason why all american v8s have the cross plane with counterweights. These v8s have all proven to be reliable. Now go into exotics, they use flat plane cranks. All of their v8s are in the 4.x litre range and dont have the reliability like the american v8s. These motors sacrifice reliability for performance gains. Flat plane cranks do not have these counterweights which allows more vibration (not good). More rpms, inertia(higher displacement in the 350r than the exotics that have been using flat plane crank for years), and vibration dont really go together.
Lets just say the ls1 has been known for reliability and good power. Ferrari doesnt have the same public opinion of reliability but they do make great power.

 

[Willmkent]

That's a very good point. I'd like to see how this new cobra holds up

 

[blk02edge]

i think ferraris being unreliable is quite a myth. They just have extensive service costs and needs which are quite played up on the good old internet. My dads buddy has had several ferraris (testarossa,360s, 430's, a 550 maranello and now a 599) and has not ever had an issue in 20 years.

ive seen people compain about other little nuisance problems but never a mechanical engine issue.

 

[SVT_Troy]

Or just stuff the new GT350 motor in a SN95 chassis.... Your welcome

 

[ctgreddy]

It might actually be very possible to do. Depending on if the block for the 5.2 is much or any different than that of a 5.0 coyote. They look very similar from the outside. And mmr has been using the 5.0 cranks in 4.6 blocks for a while which is their 4.75 engine. if the new 5.2 blocks are still the same coyote block just different rotators, then it should be quite "easy" to put a flat plane in our blocks.

 

[Svtmustang01]

This article seems to address a lot of the similarities and differences.
http://www.edmunds.com/ford/mustang...-gt-coyote-voodoo-cross-plane-flat-plane.html
It does look like it is based off of a 5.0l motor, but it also seems a lot has changed where trying to adapt a 5.0l motor would be more expensive than just getting your hands on a motor.

Edit: Also looking through the article it appears that Ford just labeled a flat plane crank with getting rid of its advantage. They added counterweights because they created another problem by adjusting the usual way the crank pins assembled in a flat plane crank car.

 

[Mustang289]

My understanding of the new flat plane - in order to achieve high RPMs, internals must be light. Our Terminator motors have forged internals allowing easy bolt on mods. Not sure what you can do on the new GT350R to increase HP.

 

[Venomous 03]

I don't think you understand what a flatplane crank and cross-plane crank are. There is no way you can fit a flat plane crank into a 4.6 motor.

*Edit: I suppose in theory if you had enough money you could make anything work.

You can order a flat plane crank from Bryant,Scat,Kellogg ETC for the 4.6.You can make any engine FPC.I know because i was so close to going that route.
You would need different cams with a different firing order and a custom special damper to accomodate for the 2nd order harmonics that come when you put a FPC in a v8(balance shafts are used in some apps.)
I couldnt find anyone to make me the damper so i decided to not go that route.plus all that money (around 4k) with minimal performance gains.
If you want the sound just get 180 degree headers.
The thing is,the bigger the stroke,theres more harmonics that come.thats why smaller displacement 4 cylinders dont use balance shafts and bigger ones do.
Why do you think everyone is questioning fords new 5.2 liter? No balance shafts.just a special damper.
Ferrari has been in the FPC game far longer than Ford,and theyve never brought out a big stroke v8.
Maybe Ford found a solution for the hamonics.

 

[SlowSVT]

Flat plane cranks are nothing new. They have their advantages and disadvantages

I'll stick with a cross plane crank thank you

 

[elcobrita]

Or just stuff the new GT350 motor in a SN95 chassis.... Your welcome

There you go. Simple lol