[AT] Rationale for firing orders

[Steve W.]

In GM at least there is a big difference in the dampeners. The inlines
basically have just a flange with the pulleys bolted on, no weight or
rubber. The reason the VW is smooth is the same, the inline and 180
degree engines both are balanced. If you look at the flywheels and front
hubs there is no balance weight on either one. They also lack the odd
rocking coupling of motion that the V style engines have. GM tried to do
something about that with the even fire 231s, using a split throw crank
and special damper. It didn't work very well and made the crank weak.


Steve Williams
Near Cooperstown NY


----- Original Message ----- 
From: "Larry D. Goss" <rlgoss at evansville.net>
To: "'Antique tractor email discussion group'"
<at at lists.antique-tractor.com>
Sent: Monday, March 22, 2004 8:33 PM
Subject: RE: [AT] Rationale for firing orders


> I think there are probably some good arguments in favor of the in-line
> six as being POTENTIALLY the smoothest running engine.  It has the
> unique condition of being both dynamically and physically balanced.  I
> have never done an actual comparison of the harmonic balancers on the
> front end of the crank, but I was led to believe they are lighter and
> smaller for the horsepower of the engine than other designs.  But then
> there's also the horizontally opposed four ala Volkswagen.
>
> Larry
>
> -----Original Message-----
> From: at-bounces at lists.antique-tractor.com
> [mailto:at-bounces at lists.antique-tractor.com] On Behalf Of Steve W.
> Sent: Monday, March 22, 2004 11:53 AM
> To: Antique tractor email discussion group
> Subject: Re: [AT] Rationale for firing orders
>
> The firing order is to even out the power pulses. In a four stroke
> engine with 4 cylinders you set it up so that one piston is always
> producing power.
> In your example starting with No.1 firing at TDC and No2 is on BDC the
> start of compression, No3 would be at TDC on exhaust and No 4 would be
> at BDC on the intake stroke. This assumes a flat crank with throws at
> 180 degrees.
> JDs make that unique sound because they actually coast 360 degrees
> between each power impulse.
> That is also the reason why Harleys make a unique sound, and why they
> shake your teeth out when they run.
> The firing order and power impulses are also the reason why an Inline
> engine or a 180 degree V are the smoothest running engines, Power
pulses
> come evenly spaced. The next best are the 90 degree V engines.
>
> Steve Williams
> Near Cooperstown NY
>
>
> ----- Original Message ----- 
> From: "Roger Welsch" <captneb at micrord.com>
> To: <at at lists.antique-tractor.com>
> Sent: Monday, March 22, 2004 12:09 PM
> Subject: [AT] Rationale for firing orders
>
>
> > Can someone help me with a brief and simple explanation of why a
> motor's
> > firing order wouldn't always be one-two-three-four?  My Allis WCs
are
> > one-two-four-three but I have no idea why....  I love to kid my
> in-laws that
> > they've always prefered John Deere Bs because they can remember the
> firing
> > order.....
> >
> > Roger
> >
> > _______________________________________________
> > AT mailing list
> > http://www.antique-tractor.com/mailman/listinfo/at
> >
>
> _______________________________________________
> AT mailing list
> http://www.antique-tractor.com/mailman/listinfo/at
>
> _______________________________________________
> AT mailing list
> http://www.antique-tractor.com/mailman/listinfo/at
>