great you're rolling again.

seems like crunchyskippy had it dead straight in first response
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Assuming you tried "15426378", you could always try "13726548" - which is the standard for the 351.

Refresh us of your engine...did you replace your cam? What year is your engine?

Lastly, I think I may remember that there was an alternate firing order for the 302...was it on the hi-po maybe? I'll have to check my books when I get home for you.
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naturally the spark needs to fire when:
a) the piston is near top position
b) both valves (intake/exhaust) are closed.

A cam tells the valves when to open and how long, but it has no influence on the pistons whatsoever.

In a full cycle the piston is up twice. once for work (spark) and once for exhaust (just pushed out old gas from cylinder).
So it might well be that when in one order the piston is exhausting in the other firing order the piston waits for the spark then your mechanic is dead on in saying: it's the cam.

You can see when comparing the orders under each other that they're the same for the 1st, 4th, 5th and 8th fire the other 4 are interchanged

15426378
13726548

just my 2 cents ..... i don't know ... I just assume. That said: if the fire order was different before putting the cam in place,m then yes. ya. twas the cam

Kalli

 

both are right, but why not move wires around since you already have the distributor in the engine? Find top dead center #1 cylinder, put the plug wire on that post. Then follow the firing order. That is how I do every engine I build, that way I am sure it is right. Yanking the distributor and not movin any wires is only more work, since you will ned up pulling it a bunch and fighting with the oil pump drive each time, then still moving the wires.

Just $.02 from someone who got paid by how fast they got the thing done..

 

Ford changed to the 351W firing order on the 302's in order to revise main bearing load, or at least according to the engineers. Supposedly the 351 firing order stresses the main webs slightly less

 

I saw on HorsepowerTV that swapping #4 and #7 in the Chevy firing order made more HP, of course theyused a cam made for the swap.

So they went from 1-8-4-3-6-5-7-2 to 1-8-7-3-6-5-4-2.

It's also interesting to note that Chevy and Ford use the same firing order for small blocks, if you number the cylinders the same way.

 

Hey,, its KALLI,, welcome back man,, havent seen you around in a while..

 

thanks man,

can't keep up with the amount of posts per day ... it's mad and I onlky get to check during work
but yes, I like to look at some of the posts, so I don't have a too bad conscience when posting my own problems ;-)

Kalli