Changing the firing order questions.

[FloridaMack]

Just about to get my 428 together and rereading everything as I go. Just realized the camshaft specs show to change the firing order. Why would they have done this? Is there an advantage? Did any FE ever come with this firing order?
O.E. was 15426378, new cam calls for 13726548.
Elgin E966P Camshaft
Application: Ford FE V8 330-428 1963-1978
Ignition Firing Order: OE (1-3-7-2-6-5-4-8)
Cam Style: Hydraulic Flat Tappet
Basic RPM Range: 1500-4000
Manufacturers Description: Fair idle, good low end torque and response.
Intake Duration @ .050": 204
Exhaust Duration @ .050": 214
Advertised Intake Duration (@ .006"): 282
Advertised Exhaust Duration (@ .006"): 292
Intake Valve Lift with OE Rocker Ratio (1.75): .486"
Exhaust Valve Lift OE Rocker Ratio (1.75): .512"
Intake Lobe Lift: .278"
Exhaust Lobe Lift: .293"

[blykins]

Very interesting.  That's a later model SBF firing order. 

I personally don't think you'll tell any difference, but I don't think I've ever seen an FE cam come like that.

[jayb]

Supposedly that firing order is easier on the mains, and it also separates the firing of cylinders 7 and 8, which can sometimes be a problem on an FE (e.g. cylinder 7 spark "crosstalks" to cylinder 8, and fires that cylinder prematurely, causing detonation; this is why it is recommended to separate the #7 and #8 plug wires so they don't run next to each other).  Also there have been reports of gains of 8-10 HP by changing to that firing order on a high horsepower engine.  No idea if those claims are legit.

I'm curious about the cam.  Did you order this special, or was it an off the shelf grind?  As far as I knew, any 5-3 7-4 swap cams had to be custom ground and ordered...

[cjshaker]

Doing a quick Google search, it appears that it's a shelf cam and listed as having that firing order, but they also call it "OE", which it's not. It's also a very mild cam, so I don't see the advantage to that firing order. I think I'd verify that firing order during a mock-up. It may be a factory typo or screw up, maybe made by someone who only knows later smallblocks and made an assumption that all Ford V8s are that way.

http://www.competitionproducts.com/Elgin-Hydraulic-Flat-Tappet-Camshaft-Ford-FE-204_214-050-486_512-112-LC/productinfo/E966P/#.Vy4Ul-RanfY

[jayb]

If its an off-the-shelf cam, I'll bet you are correct that the firing order is simply mislabeled.

[My427stang]

If its an off-the-shelf cam, I'll bet you are correct that the firing order is simply mislabeled.

X2  Elgin doesn't do anything fancy

[FloridaMack]

It is a off the shelf grind. Part of a kit I ordered, cam, lifters, pistons, bearings, gaskets all in one. Today I went through my parts and started putting it all together and found that isnt even the cam they sent me. It was advertised with a RV towing cam part # E966P and recieved a stock replacement cam part # E573S that is ground to C6AZ-6250-A specs. I dont know enough about cams to know if I even want to procede with it. Would I be able to hear either one of these at idle anyway? I dont know.
The E573S specs   
http://catalog.elginind.com/app/Engine_tech.asp?part=E-573-S&category=Camshaft
The E966P specs
http://catalog.elginind.com/app/Engine_tech.asp?part=E-966-P&category=Camshaft+High+Performance

[57 lima bean]

(V8's)have the same firing order has with an alternating inside/outside cylinders.I'm sure harmonics and and port angle can make a difference on what one will be next to improve performance.

[CaptCobrajet]

I'm sure its a typo on their part.  There are no iron core FE cams with other than the 1-5-4....order.

As far as firing orders go, I have tried them all....the 1-5, the 1-3, and the 1-5 with the 8/2 swap.  Nothing there.  Any way you do it, you still have two cylinders firing next door to each other.  It just depends on which side, and which end you prefer to have that condition.  7-8, 6-5, or 2-1.....the engine don't know what labels we give the cylinders, and it don't know it's right from it's left, or it's front from it's rear!

[machoneman]

long ago (and far away!) we drag raced BBC's in 10 second UDRA door slammers out of Peter Guild's Des Plaines, IL based Pro Motor Engineering (now in NC with engineer Jerry Baker making only NASCAR engines) and they were on the cusp of the Chevy F.O. change.

They believed it did work on Chevies for a small gain (don't remember how much) simply since the paired intake ports, unlike the separated intakes in Fords, had more of charge 'stolen' on intake open cycle with the standard F.O. A few NHRA legal Comp cars running out of PME's shop did see an improved e.t. 

They did also say that unless it was a max effort, high $$$ Comp/Eliminator type engine....don't bother! We didn't!

[CaptCobrajet]

Yes sir, some of the Chevy and Buick headed Comp stuff did benefit, like you said, because of runner layout.  The FE does not share that layout.  The general thought was that it had to be a tunnel rammed 10K-plus rpm engine to see the gains.  There is a savvy Comp veteran up the road from me a piece here in TN that has tried just about everything......and most of what he tries works..... Lol.