Firing order
10-18-2007, 11:48 AM
#11
6th Gear Member
Join Date: Oct 2006
Location: Cork, Ireland
Posts: 6,417
RE: Firing order
great you're rolling again.
seems like crunchyskippy had it dead straight in first response
=================================
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.
=================================
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
seems like crunchyskippy had it dead straight in first response
=================================
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.
=================================
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
10-18-2007, 12:00 PM
#12
5th Gear Member
Join Date: Mar 2005
Location: Marquette Mi
Posts: 3,566
RE: Firing order
ORIGINAL: boogerschnot
I was just saying that if the dizzy was 180 out, he could easily just point the rotor in the oposite direction that it was pointing by pulling it up instead of finding tdc and then spining the rotor and putting it back in on #1.. Only if you actually had it timed to the correct exhaust stroke..Whatever you want to do though..
ORIGINAL: TexasAxMan
It doesn't matter which way the rotor points, only that the cap post it points to is where you hook up the number 1 wire. You can't remove and reset your distributor 1 tooth off, the oil pump drive would not line up (unless you turned it too). If the distributor is in and the oil pump drive is properly connected, get the engine to TDC on the compression stroke of #1, note where the rotor is pointing (which post of the cap) and start there.
It doesn't matter which way the rotor points, only that the cap post it points to is where you hook up the number 1 wire. You can't remove and reset your distributor 1 tooth off, the oil pump drive would not line up (unless you turned it too). If the distributor is in and the oil pump drive is properly connected, get the engine to TDC on the compression stroke of #1, note where the rotor is pointing (which post of the cap) and start there.
Just $.02 from someone who got paid by how fast they got the thing done..
10-18-2007, 12:08 PM
#13
6th Gear Member
Join Date: Apr 2007
Location: California
Posts: 10,468
RE: Firing order
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
10-18-2007, 12:52 PM
#14
4th Gear Member
Join Date: Aug 2007
Location: Houston, Texas
Posts: 1,692
RE: Firing order
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.
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.
10-19-2007, 08:29 AM
#16
6th Gear Member
Join Date: Oct 2006
Location: Cork, Ireland
Posts: 6,417
RE: Firing order
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
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
Thread
Thread Starter
Forum
Replies
Last Post
bradleyb
Classic Mustangs (Tech)
3
11-27-2015 07:50 PM
