Fireing 180

[Oelke]

Hi, Yesterday a friend asked me what reason John Deere had for #2 piston to fire 180 degrees after #1. instead of the full turn. I could not answer his question. I have rebuilt a dozen or more old two bangers and knew thats how they fired but never ever questioned it and I am 77 years old. If you know please reply. I was told that Harley Davidson fire the same way. Thank you . ---------Harold

 

[jason1816]

it runs like any other motor would. just that it only has two cylinders and that there is no balancing of the motor...like 1-8-6-5-4-3-7-2...has to balanced or it would shack the crap out of you and tear itself apart..

there's just too much power in a deere ..

 

[teddy52food]

In order to fire 180, the pistons would both go back & forth together. It would take a lot of weight to counter-balance it. Then the balance weight would cause an up & down vibration. The way they are built works good on 2 cycle engines.

 

[Mark-Ia]

I went to the archives and found this. Thanks John T.
Ron, The 2 Pistons (crankshaft throws) are 180 degrees apart/opposite i.e. ones at TOP of stroke when others at BOTTOM. The Left (Flywheel side) piston fires first on its TDC and then 180 degrees of Crankshaft rotation later, the Right (Clutch pulley side) fires.
They, therefore, fire at O degrees (Left)
180 later at 180 degrees (Right)
then theres that long 540 degree
coast cycle before No. 1 fires again

When you hear that pop pop pop pop sound, ITS NOT No. 1 then No. 2 firing,,,,,,,,,the "pop" you hear is the combination sound of 1 then 2 firing only 180 degrees later. Thats how JR Hobbes describes it anyhow and if you do the math and consider the human ears response, it makes sense you cant/dont hear 1 then 2 pop pop, its ONLY the single combination "pop" then 540 degrees later another combined "pop"

Made sense to me when I did the math at least, any different opinions n explanations out there????

Happy New Year yall

John T

 

[LarrySTN]

It is all about balancing the engine. If it fired every 360 it would sound even firing but it could never be balanced (without balance shafts). If you have ever been to an old engine show and saw the large single cylinder engines run you noticed them walking back and forth every revolution of the flywheel, that would be the same effect if Deere had their two cylinders firing every 360. The weight of the pistons and rods counter act each other as the tractors were built.

 

[SMinWi]

Check this link out.

http://www.vinsonfarm.net/jd_animation.html

 

[JD 5020 guy]

Some of the older 2 cylinder equiped tractors did have a 360 firing order such as the IH titan 10-20. But top rpms was less then 500 so the balance was not a big issue.

 

[Oelke]

Thanks a pile gentlemen I will pass the info on.------- Harold

 

[John T]

Gee Mark, I long ago forgot I once knew that lol......On the late Duane Larsons website or his CD (I forget where it is) he also did an analysis on the 180 firing and explained better then I could about that pop pop pop pop sound and why its NOT pop pop - - - - pop pop

John T

 

[Machinery-Man]

I've always had the concept of the two cylinder JD as like a stationary engine with wheels and clutch. JD made this tractor around a stationary type engine for almost if not 50 years. The low rpms was the reason for the durabiltiy coupled with a like overhead valve processed but laid down. Not much complicated about the tractor....could still be building if folks wanted the durability instead of speed.

 

[Anonymous-0]

if they built one about 500 hp that would pull a feild cutl at 8 mph it would be to big to get in the gate

 

[Anonymous-0]

if they built one about 500 hp that would pull a 50ft field cultavator at 8 mph it would be to big to get in the gate

 

[shawnee]

http://www.youtube.com/watch?v=1l3wnAo_oRg

That will pull it 15 mph or more!!!!