Coyote Wiring: 2nd Gen F-150 donor + Ford Racing Controls Pack

[TomP]

Good onfo there, thanks!

Question. Is it just the cams that make the firing order different? If one were to use aftermarket cams for the Mustang would it eliminate the need to change the Control Pack firing order? What else is different between the truck and Mustang engines internally? Is the lower compression made by the pistons or are the heads bigger chambers?
Quite a few truck engines available cheap around here but used Mustang engines seem to cost almost what the new crate motors go for and the crate motor wasn't likely subjected to five minute long on the rev limiter burnouts like crashed Mustangs tend to be.

[CoyoteCobra]

Originally Posted by TomP

Good onfo there, thanks!

Question. Is it just the cams that make the firing order different? If one were to use aftermarket cams for the Mustang would it eliminate the need to change the Control Pack firing order? What else is different between the truck and Mustang engines internally? Is the lower compression made by the pistons or are the heads bigger chambers?

Different cams change the firing order. If you change the cams/firing order, you still need to address the wiring issues as the 150's engine harness does not have the connections for the IAT/MAF.

Other differences include: MAP vs MAF (which the controls pack changes to MAF), Different Intake manifold (which you should swap to a GT anyway), 0.5 compression lower via different pistons (10.5 vs 11), different timing cover/accessory drive arrangement, and a slightly smaller oil pump on 150 vs mustang. They also have a different oil-cooler arrangement. The heads are the same.

My f-150 engine also has piston cooling jets, something I had heard was removed from the 2nd gen and up engines but mine definitely still has them. Not sure if it was just the mustang that lost the cooling jets.

The 1st gen 150 has the same firing order as the 1st gen Mustang, but it's also down a lot more on power than 2nd gen 150 with even milder cams and 360HP vs 385HP stock. 2nd gen coyotes have bigger ports, bigger valves, IMRC, and supposedly a little better VCT.

Originally Posted by TomP

Quite a few truck engines available cheap around here but used Mustang engines seem to cost almost what the new crate motors go for and the crate motor wasn't likely subjected to five minute long on the rev limiter burnouts like crashed Mustangs tend to be.

Yep and most crashed f150 were probably not beat on too badly and automatic also makes the likelihood of the 5 minute rev limiter incident less likely too!

[eschaider]

Originally Posted by TomP

Good onfo there, thanks!

Question. Is it just the cams that make the firing order different? ...

That is essentially correct, Tom. Significantly there are also pin / wiring reassignments for things like IAT, MAF (I believe), MAP sensor etc. that need to be accommodated. CoyoteCobra did a very nice job of sleuthing out the various wiring / sensor translations necessary along with the firing order differences.

Ford likes to mix things up with firing orders. They have used at least three different firing orders on modular engines and they have basically three favorites that have been used over the years since the first Flathead V8. Here is a listing of the various possible firing orders for GM style (left bank forward) and Ford style (right bank forward) engines.

A couple of comments about the chart, while left and right bank forward engine configurations mix up the firing orders so to does cylinder numbering. Ford chooses to number sequentially front to back on a bank. GM and Chrysler put odd numbered cylinders all on one bank and even numbered cylinders all on the other bank. As if not to be out done Ferrari numbers their V8 engine cylinders sort of like Ford except they go big to small front to back, i.e. 4,3,2,1 rather than 1.2.3.4. That makes cylinder firing order distinctions difficult to visualize in your head. The best way is to draw out eight circles on a piece of paper beginning with the #1 hole and draw arrows to each subsequent cylinder in firing order sequence.

A couple of additional thoughts; flat plane cranks can be made with the rod journals alternating up and down crank pin to crank pin or they can be made with the front crank pin up, the middle two down and the last (back) crank pin up. The two different crank styles further complicate the flat plane crank firing orders that are possible.

The other thought that I find interesting was Cosworth's firing order change in the 90's. Although there were other significant engine developments also, the 90's F-1 engines with the new firing order became the first F-1 engines to be able to operate at 20,000 rpm (and higher). In fact it was because of this new found rpm capability that F-1 rules began to limit maximum on track in competition engine speeds.

The aftermarket has done a fairly significant amount of experimentation with GM style firing orders. Firing order changes sometimes are designed to even our heat in the block and heads, sometimes to prevent one cylinder from 'stealing' charge from its neighbor, sometimes to mitigate vibration and sometimes to gain horsepower.

By and large the power improvements have amounted to about 1% or so. Not significant to John Q. Average. To a racer in a competitive class with qualifying fields from fastest to slowest qualified within one or two tenths of a second, these differences can make the effort and expense worth while. For the rest of us mere mortals — not so much.

In the FWIW bucket the best power producing firing order traslated to the Ford cylinder layout turns out to be Ford's original Flathead firing order — isn't that interesting.

Ford has used several of these firing orders on the Coyote already which is the origin of the onerous buy parts admonition to convert certain Coyote engines to use other Coyote ECU's. For guys like us that transplant engines into cars they did not come in you need to pay attention when you do things like ordering camshafts.

If you order cams for a firing order different than your ECU is pinned for then you will be facing either a wiring harness rework or a new set of cams to work with the ECU you have. While not a buyer beware scenario it is definitely a buyer be aware scenario. An interesting parallel I like to remember from time to time is the imortal words of the Knight;s Templar to Indy as he is trying to select the 'True Grail' from the many grails spread across the table before him in the Knight's cave. The Knight's Templar admonishes Indy, "Choose wisely, he (the dead NAZI on the floor) did not ..." those words also also apply to us as we navigate through this increasingly interesting firing order landscape.


Ed