I have always wondered why they did this, haven't been able to find an answer. Does anyone know?
Is it for better balance or something?
Is it for better balance or something?
Why did ford change the firing order for H.O. and 351 W motors?
- Thread starter Great68
- Start date
Route666
Active Member
I've heard it is for less resonance in the crankshaft, kind of balancing. Really there can't be many reasons can there?
Yes, this is the reason I have always heard also. Think about it, with the firing order 1-5-4-2-6-3-7-8 the first main bearing is loaded by two consecutive pistons firing one right after the other with the harmonic balancer right there to take the shock....with the 1-3-7-2-6-5-4-8 this loading is transferred to the rear main journal with has much more support and is balanced by the flywheel/clutch or torque converter assembly. Now I do not have the specifics to why this arrangement is better, but according to Ford the latter firing order is much easier on the crankshafts. All I know is I did snap the snout off of the crank in the Shelby many years ago, it broke right behind the #1 jounal....luckily the damage to the block was minimal and repairable.D.Hearne said:
FYI.....did anyone ever think about why the later model 5.0 has such a distinctive exhaust sound that differs from an early SB Ford? It is the firing order that makes the difference.
You will not notice it without mufflers, but through the exhaust I can tell the difference between an early 302 and a late model HO 302 just by listening. It may be just me but others I know have confirmed that there is a different sound. It is also not as noticeable at idle but more so at speed.
Ronstang said:
I have to agree, my friend's 5.0 definately has a different from my car which I can notice. We both are running the same mufflers.
TOM B
20+ Year Stangneter 
When I built my engine (early 302) I went with a Comp roller cam for a 5.0 and used the 5.0 firing order. Produces more even power, and you have a lot more choices in cams.
ratio411
Founding Member
I believe that F/O does play a role in sound.
There are also many other factors too though... cid, compression, types of metal used in engine, etc...
I don't know that I could do it today, but in high school auto shop I used to listen to an engine and tell folks what it was. I could tell the difference between a W, C, M, L, FE, and SBF. Friends asked me how, but I couldn't explain.
Dave
There are also many other factors too though... cid, compression, types of metal used in engine, etc...
I don't know that I could do it today, but in high school auto shop I used to listen to an engine and tell folks what it was. I could tell the difference between a W, C, M, L, FE, and SBF. Friends asked me how, but I couldn't explain.
Dave
Route666
Active Member
I don't think you could tell the difference between the sound of two motors with only different firing orders. You have things like carburettors, carb tune, intake manifold, timing, camshaft, sparkplugs, sparkplug wires, age of wires, age of fuel, stage of wear of engine, etc. to change the note.
If one were to build two exact engines with the only difference being firing order, and put them into the same car with the same exhaust, I bet they would sound the same. After all, the timing of the combustions events will be the same, just coming from different cylinders. And you can't tell it is a different order when 10 combustions are happening every second (at a minimum).
Power delivery and strength may be different however.
If one were to build two exact engines with the only difference being firing order, and put them into the same car with the same exhaust, I bet they would sound the same. After all, the timing of the combustions events will be the same, just coming from different cylinders. And you can't tell it is a different order when 10 combustions are happening every second (at a minimum).
Power delivery and strength may be different however.
I do remember that in older cars with equipment falling into disrepair, having the 7 and 8 cylinders firing side by side, older plug wires would sometimes bleed into each other. I was always taught to route the 7 and 8 plug wires on opposite side of the loom from each other.
68stangman
New Member
Don't forget that the 5.0 has a roller cam. The early fox's with carbs still have a different sound. I think the roller cam has to do with it.
ratio411
Founding Member
Yeah, there is alot more involved than just firing order. IMO it does make a difference, but not enough to pick it out as a sole change.
Reducing the load on the main bearings was one reason, but the other reason was that Ford had a 351W cam in their parts bin that they found worked well with the new 5.0 roller engine. Which reason came first or was most important has never been told by anyone official. They didn't want to design a new cam if they didn't have to so maybe someone said, hey this is easier on the crank too. Bingo, desicion made.
HistoricMustang
Active Member
Ford has always been messed up in the engine department. Chevy kept it simple.
Ford did put the darn distributor up front and that makes up for all the crazy engine designs. Nothing worse than a distributor next to the firewall.
HistoricMustang
www.historicmustang.com
Ford did put the darn distributor up front and that makes up for all the crazy engine designs. Nothing worse than a distributor next to the firewall.
HistoricMustang
www.historicmustang.com
66P51GT
New Member
HistoricMustang
Active Member
I continue to be amazed at the amount of knowledge here at StangNet.
D. Hearne and some of the others are simply fantastic and I only wish to someday be in that bracket. I can not even count to 8 and they are discussing five firing next to six and seven next to eight.
Great stuff.
HistoricMustang
www.historicmustang.com
D. Hearne and some of the others are simply fantastic and I only wish to someday be in that bracket. I can not even count to 8 and they are discussing five firing next to six and seven next to eight.
Great stuff.
HistoricMustang
www.historicmustang.com
