firing order - Diesel Forum

JimJoe · 09-13-2006, 03:39 PM

Can anyone enlighten me about thi silly firing order? Is there a particular reason for that or did the Ford techs just throw dice?

Jim

ta152h0 · 09-13-2006, 06:19 PM

I am sure this is one of those " I got nothing else to do " posts. Ford tech's don't design engines, International engineers do. Has everything to do with keeping the engine from physically rocking too much and breaking engine mounts. When I worked on people's engines I noticed the firing order of most v8's was always the same but the cilinder numbering system was different, resulting in what appeared to be different firing order.

GrampyJim · 09-13-2006, 08:00 PM

It has to do with many considerations.... crankshaft loading.... harmonics..... vibration.... block distortion/loading (that big lump of cast iron is NOT the impervious object that most think).

The 302 (not a diesel, but a shining example) started out with a 1-5-4-2-6-3-7-8 firing order. The 351, nearly identical except for deck height and journal diameters, had 1-3-7-2-6-5-4-8. Later, the HO 302s got the 351 1-3-7-2-6-5-4-8 firing order and, IIRC, somewhere around 94, all 302s got the same firing order.

Is there something that makes the firing order appear "silly" - other than the cylinder numbering on the diesel is different than the cylinder numbering on the gas?

hitecdan · 09-14-2006, 12:17 AM

The firing order for the 6.0L is 1-2-7-3-4-5-6-8. What was the question again?

GrampyJim · 09-14-2006, 01:37 AM

Taking in to account the difference in cylinder ID, the 6.0 has the same physical firing order as the early 302....

JimJoe · 09-14-2006, 06:08 AM

The reason behind that question is that I am wondering why the Ford / Intl. engines are so loud compared to the European ones. Also I feel that a 8 cylinder engine should not rattle that much.

Said that the best logical order for me would be 1-5-3-7-2-6-8. But why they did not chose that one?

Of course the design if from Intl; just wrote Ford by incidence.

Jim

GregH · 09-14-2006, 08:42 AM

One of the other issues with the early 302 engine was the likelyhood of inductive crossfire between the 7 and 8 cylinders. If you'll notice now there are no cylinders on gasoline engines side-by-side that fire one after another.

ta152h0 · 09-14-2006, 12:43 PM

That firing order works fine on a V7 engine but a V8 is different. [img]/ubbthreads/images/graemlins/biggrin.gif[/img]

JimJoe · 09-14-2006, 03:46 PM

Ok [img]/ubbthreads/images/graemlins/grin.gif[/img] I meant 1-5-3-7-2-6-4-8. 1-7-2-8-5-3-6-4 would be ok, too.

Jim

OMCUSNR · 09-14-2006, 04:47 PM

[ QUOTE ]
The reason behind that question is that I am wondering why the Ford / Intl. engines are so loud compared to the European ones.

[/ QUOTE ]

Has nothing to do with the firing order, and EVERYTHING to do with the injection systems used. The 6.0 has the HEUI injectors, which although they use high pressure oil, and are under the valve cover, cannot keep up with multi injections / firing. Its the "split-shot", or multiple injection event that the common rail injectors can do that makes them quieter.

Ford tryed to do this with the early programing on the 6.0, and found that the HEUI injectors just could not keep up mechanically with the electronics. When the complaints of surging, romping started, the 1st thing that went was the split-shot, and the trucks got louder.

The 6.4 should be noticablly quieter because of its common rail system.

444-4D · 09-14-2006, 05:25 PM

[ QUOTE ]
Taking in to account the difference in cylinder ID, the 6.0 has the same physical firing order as the early 302....

[/ QUOTE ]

Which is also the same as the 1-8-4-3-6-5-7-2 used on many GM engines including the small block chevy.

GrampyJim · 09-14-2006, 10:21 PM

Not to mention Dodge, too....

Too all... this relates back to the "running mate" discussion from not too long ago.... There are only so many available firing orders unless they go to a 9 main bearing crank - and I can't see that in the near future....