Shelby GT350 5.2-liter Engine

[EditorTurner]

Voodoo Doll
Taking a closer look at Ford’s Flat-Plane-Crank 5.2-liter engine cutaway display
By Steve Turner and Tob
Photos by Steve Turner

Though we have seen plenty of GT350 photos at this point, Ford has avoided releasing too many pictures of the Flat-Plane-Crankshaft 5.2-liter engine. Designed to run up to 8,200 rpm and produce over 500 horsepower, there is still much to learn about this naturally aspirated powerhouse.
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[Tob]

I find it interesting how similar this engine is to the current Coyote engine as much as Ford kept reiterating that it was mostly new. Considering all the talk about the challenges in taming a "large displacement" FPC engine (in terms of NVH, etc) I was a bit surprised when I saw the complete rotating assembly. The clutch looks interesting but the balancer certainly doesn't. And I really thought we'd see some connecting rod exotica too. For all the talk about the crank I thought we might see something special (beyond the inherent CW indexing) there too, such as fully radiused fillets on the journals. Nope. However unique this powerplant may be it is clearly based on the current 5.0 powerplant.

 

[EditorTurner]

Thanks for the help, Tob. Your eye for detail is second to none.

 

[Voltwings]

What i'm most interested in is the comment about that manifold offering "cobrajet like performance."

We've already seen a few examples of just bolt on S550 GTs making numbers similar to Boss and CJ powered S197 5.0s, and this Voodoo intake manifold is going to make things that much better? Incredible. It doesnt have your typical Na, high runner design, like the Boss and CJ though ... is there a chance this manifold will actually hold onto some torque? If this manifold makes as big of a difference as claimed, AND doesn't impact torque as drastically as the boss and CJ, that could be wicked an all motor 5.0 ...

 

[STL5OHSLOW]

I wonder how long it will be before they produce the intake so we can see comparison tests done with the stock 5.0 intake as this new intake. Also thought it was interesting to see that the heads look as if they could change over as well

 

[Tob]

Thanks for the help, Tob. Your eye for detail is second to none.

You and Wilson set the bar very high and showed the entire community how it's done when you did your Coyote and Trinity in-depth articles at 5.0 magazine. This engine certainly merits at least as much attention.


Here's a quick comparison of driver side exhaust manifolds. The GT350 5.2 up top, 2011-2014 Coyote in the middle, and the 2015 Coyote at bottom (Ford cheated by slicing the top of the attached converter to emulate the flange "look" and not attract too much attention).

Note that the 5.2 collector is actually a casting as opposed to a welded stamping on the Coyote engines. The 5.2 manifold on the cutaway engine also appears to be hand welded instead of being done by machine/robot on the Coyote manifolds. May just be because production has yet to fire up where it would then be (I assume) done robotically. Note how the tube merge count differs that Steve mentioned as well. Thankfully, Ford didn't fuse a converter directly to the manifold like the 2015 Coyote. The manifold to cylinder head flange on the 5.2 engine is also very similar to that of the Coyote.

 

[NELCO]

Awesome Info..........................................

 

[HISSMAN]

It seems like with every new engine iteration the connecting rods always give me the he-bee-Jebees... (Save for the Manley Terminator rods). However, my gut is always proven wrong.

 

[GT Premi]

It seems like with every new engine iteration the connecting rods always give me the he-bee-Jebees... (Save for the Manley Terminator rods). However, my gut is always proven wrong.

It's because people are always lamenting the use of powdered metal rods, propping it up with anecdotal evidence of failure; i.e. a pic of some bent rods where it's later found that the owner spun the engine out to like 9K RPM or some other extreme abuse way, way beyond the design limitations of the rods.

 

[Tob]

While PM rods probably wouldn't be the first choice of many here at SVTP they are a bit better than when they were first introduced. Not long ago someone at Ford made the claim that the PM Boss rod was the strongest Ford had ever produced. I have a sense that we'll be hearing that this rod is even stronger than that one.

 

[01SVTSnake]

Tob what are your opinions on the plastic oil pan?

 

[Tob]

I'm aware of numerous plastic pan issues on Ford trucks, be it cracking, warpage, faulty plastic drain plugs, etc. That does raise an eyebrow and I believe a valid concern. Theoretically, the move to plastic makes sense. They save weight and should be able to withstand the same rigors as previous steel pans at least as far as Ford durability standards are concerned. When Ford went to a cast aluminum pan for use on the '13/'14 Trinity engines I immediately wondered about impact resistance/cracking. I can't think of a single instance being reported and paraded over the web (yet, anyway). The same goes for plastic which has had issues to date. Long term heat cycling, thermal shock from cold to hot, impact resistance levels, and the ability to maintain proper sealing qualities throughout, are conditions that Ford has supposedly conquered and as such enabled the use of a composite. That said, I'd much prefer a steel pan as it is a part I'd rather not have to ever worry about. Considering the small volume of these engines, Ford could have farmed out a really trick steel pan. Added cost? Yes. Added weight? Yes. Worth the piece of mind and increased durability potential? Absolutely.


I suppose we won't see much more picking and choosing as the GT350 program was one that lived by a pretty clear performance metric. In essence, if a part doesn't add "performance" they didn't use it. And we're all aware of the concern Ford had with respect to weight so a plastic pan was a natural. In my view however, the weight savings isn't worth the potential i$$ues. Oil pans generally are not that heavy to begin with when made from steel. It looks as if typical weight savings are under 50% if the following chart means much. I forget which platform this related to (Fusion, etc) but I believe one could reasonably assume that related 5.2 engine components would see typical weight reductions respective of relative size.

I'm all for composite valve covers and it looks as if Ford has finally figured out how to make a plastic intake manifold that doesn't warp/leak (a debacle for many Ford owners previously). The difference is that these components are mounted atop the engine and as such not a concern with respect to impact or the slip of a jack. I'm a dinosaur and like my connecting rods forged the old fashioned way as well as a steel oil pan. Ford has been legislated into a position that is taking them in a different direction and I credit them for their efforts. Evolve or die I suppose, which didn't play out too well for the dinosaur.:uh oh:

 

[GT Premi]

I also found it interesting (and cool) that they're using a composite oil pan. But my second thought was, removing cost as a factor, why didn't they use a dry sump system on the GT350R? Composite components could still have been used there.

 

[Tob]

...removing cost as a factor, why didn't they use a dry sump system on the GT350R?

You removed the reason and then asked the question. While we have yet to be given a firm price for the GT350/GT350R, Ford has made it clear that they've done their best to keep the MSRP down. Out of curiousity, where do you see room for a reservoir as well as a pump assembly/bracket?


Something else - the clutch/flywheel. Note the top two photos of the GT350 clutch below, followed by that of a factory 5.0 Coyote clutch. The dual mass flywheel is an interesting piece and the 15-mm dual disc clutch is of much smaller diameter than that of its 5.0 brethren.

With much lower power numbers (than the Trinity) to contend with it will be interesting to see how durable it proves to be.

 

[GT Premi]

You removed the reason and then asked the question. While we have yet to be given a firm price for the GT350/GT350R, Ford has made it clear that they've done their best to keep the MSRP down. Out of curiousity, where do you see room for a reservoir as well as a pump assembly/bracket?

That's the beauty of composites. It can be molded to fit just about any space. Even the pickup tube can be molded into the wall of the reservoir.

Something else - the clutch/flywheel. Note the top two photos of the GT350 clutch below, followed by that of a factory 5.0 Coyote clutch. The dual mass flywheel is an interesting piece and the 15-mm dual disc clutch is of much smaller diameter than that of its 5.0 brethren.


...


With much lower power numbers (than the Trinity) to contend with it will be interesting to see how durable it proves to be.

It'll be more durable than you think. It has a fairly small amount of torque to contend with, yet very high RPM duties. The smaller diameter and smaller mass provide for those high RPM. Not to mention much quicker revving.

 

[Voltwings]

I'm sure the last thing they want is the clutch sticking on a motor actually meant to go to 8k.

 

[Tob]

Yet the GT500 suffered clutch woes almost from inception to the end of production. Again, with lower output we should see less complaints than with the '07-'14 GT500's.

That's the beauty of composites. It can be molded to fit just about any space.

I never argued with respect to material for a potential drysump reservoir as much as you'll typically see them as cylindrical in nature and tall.

The GT350 engine bay...

Tank and location on the GT...

What GM chose for their "Top Dog" Corvettes...

With cost as a driving constraint there was no way Ford was going to the trouble of fitting a dry sump system to this car. Would have been nice, I'll grant you that.

 

[Wiseguy]

You removed the reason and then asked the question. While we have yet to be given a firm price for the GT350/GT350R, Ford has made it clear that they've done their best to keep the MSRP down. Out of curiousity, where do you see room for a reservoir as well as a pump assembly/bracket?


Something else - the clutch/flywheel. Note the top two photos of the GT350 clutch below, followed by that of a factory 5.0 Coyote clutch. The dual mass flywheel is an interesting piece and the 15-mm dual disc clutch is of much smaller diameter than that of its 5.0 brethren.

With much lower power numbers (than the Trinity) to contend with it will be interesting to see how durable it proves to be.

Looks to be self adjusting clutch too. Good info and looking forward to this car! Good stuff Ford...

 

[Tob]

More and more I see a heavy Coyote influence on the 5.2 FPC engine.

Note the following:

Throttle body

- The 5.2 engine may utilize a larger diameter butterfly but the angle at which the TB sits is very similar. Bolt pattern is similar although the 5.2 may have a larger center to center bolt pattern. The IAC hardware is flipped up top whereas the Coyote is down low.


Upper Coolant passage

- Just to the right of the TB. Area is similar between the but it looks as the the area on the 5.2 may extend further away from the cylinder head than on the 5.0 engine.


Timing Chain Cover Bolt Pattern

- As much as much of the 5.2 engine block has been scalloped for display purposes you can see a near identical pattern at what is left of the water pump bolt face as well as up near the cylinder head. It would make sense for these two engines to share the same cover and it'll be interesting to see if they indeed do.


The Variable Valve Timing Hardware

- At the top of each chain (upper right) the hardware looks very similar, once again, as does the hardware for the chain tensioning system.

From this perspective the valve cover looks like a match. So does the ribbing/bolt pattern on what is left of each timing cover.

Select tuned? Seriously?

Intake manifold flange face comparison...

 

[2L8IWON]

GREAT points Tob! This gives me great hope, that if the motor is not that large or a departure from the Coyote, that the car won't be super expensive. I know I've heard many say that we will be surprised by the price... hopefully this contributes to a low price point