347 firing order question - Ford Mustang Forum

 
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post #1 of 7 (permalink) Old 05-22-2009 Thread Starter
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347 firing order question

I can't figure this one out. I changed cams and it changed my firing order. You time a motor off the crank and according to the piston relationship to the TDC. So how does the cam change this? It works wonderful, but seemed awful funny changing those wires...lol
I have a 79' 302 with a 347b stroker kit and a 351 retro fit cam that fit the power range I wanted better. I forgot that a 351 uses the HO firing order when I got it. I put the wires on it in the original position and had no power. I went to the 351 firing order and it is a flippin monster....you can't get traction at 45mph with 245/45-17's with a posi......


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post #2 of 7 (permalink) Old 05-22-2009
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Its really hard to explain how the cam changes the firing order. TO put it simply, its how the Cam lobes are arranged on the Cam shaft. You would have to look at Cam to get a better Idea.


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post #3 of 7 (permalink) Old 05-22-2009
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It's a combination of the two that sets the firing order. But the cam actually has the final "say" as to what the firing order is.

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post #4 of 7 (permalink) Old 05-22-2009
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The main thing is you sorted out the timing issue. That'll be something you'll remember I bet.

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post #5 of 7 (permalink) Old 05-24-2009 Thread Starter
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remember..lol?

what spec would you like off the top of my head after tripple checking everything from pushrod pre load, ignition timing (initial, total, with or without vaccum) any question about degreeing in a cam.....recurving a distributor.....compression hot or cold.....torque specs for the stock or ARP bolts????????
I am glad it was something so simple. I at least know everything else is set perfect. I just got back from a lil test drive....It pulled the front wheels off the ground and sounded so good at 6000rpm it brought a tear to my eye. Now that is how it is supposed to run!

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post #6 of 7 (permalink) Old 05-25-2009
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Quote:
Originally Posted by lilorange79 View Post
what spec would you like off the top of my head after tripple checking everything from pushrod pre load, ignition timing (initial, total, with or without vaccum) any question about degreeing in a cam.....recurving a distributor.....compression hot or cold.....torque specs for the stock or ARP bolts????????
Stuff like this give me headaches. And it was just brought up on another forum by a new member here(vristang). And since it was brought up, I seem to notice it more and more.

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post #7 of 7 (permalink) Old 05-25-2009
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Quote:
Originally Posted by 89coupe View Post
Stuff like this give me headaches. And it was just brought up on another forum by a new member here(vristang). And since it was brought up, I seem to notice it more and more.
Huh?
Who?
I didn't do that, did I? Wait, what did I do??????





With carbs, you can simply swap the plug wires and change the firing order to match the cam.
With efi, you would have to swap the injectors around as well as the plug wires.
Since the ecu corrects fuel adjustments per bank, you will end up with runaway correction factors if you try swapping the injector plugs around.

I think the OP was carb'd though
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