Navajo350

Member


I remember reading in a green magazine a long time ago that the 620 had 20% more horse power than the 60, hence "620." But, as for the 630, they named it 630 just to have a similar model as the 620, but with different sheet metal? I mean, same engine and horse power as the 620, not 30% more than the 60.

Thanks,
Robert
 
The "20 series" number has nothing to do with the HP comparison..It only identified the next evolution of the models..
 
Sorry Tim, but it does. The 620 and 720 have different engines then the previous models. The 520 has a different head then the 50 and increased the compression and RPMs to give it eight more horses. That is ware they got the 20 present from. So they added that to the model number. And the 720's gas engine is completely different then the 70's.
 
This is the first time I have heard this analogy...and your saying the same held true with the 30 series?? And this held through out all the models??
 
This is why I have a hard time understanding them naming the 20 series for that reason...but I guess it's possible..
 
There are so many more differences between the 50-520 and 60-620 models.
They had to call them something so that 20% HP figure seems close ? and makes as much sense as anything.
I learned long ago there is no rhyme or reason to JD model numbers ! Especially the last 20 years or so. Also look at all the times they use the same numbers for completely different machines ! Craziness.
 
The 20 series and 30 series have basically identical engines- that is why none of the 30s were tested at Nebraska, because the state did not require them to be tested with no engine changes.
SO HP is the same. No changes in engine speed or displacement between 20 and 30 series.

The 30 series was brought out to be sort of a "place holder" prior to the NG intro. The sheet metal was changed, electric start became available on the 830 diesel, new fenders on the row
crops, but no big changes internally. I think the camshaft may have been a bit different on the 730 diesels to keep em from running backward, but that change may have happened with the late
720s too????
 
It can happen when they lug down so hard that they stall,then the light up and run backwards,,I have seen it happen a couple times..
 
When the 20 series were introduced with their all new engines Deere used the new combustion chamber design the was developed for the upcoming New Generation tractors. It worked very well and may have given the engineers some insights into any weak points. The 30 series were a fill in model because the New Generation wasn't quite ready yet. Deere used them to get the public ready for the new look and styling that was coming soon, the slanted steering wheel, fenders with lights, and the rounded body design.
 
Tim, I apologize, I was only talking about the two cylinder 20 series. As far as I've read John Deere never done this again. In as far as the 4010-4020s are concerned, when flaws started showing up in the 4010s they started designing the 4020 series. Making it stronger, and heavier where needed. They added more horse power because the power shift transmission ate six to eight horse. To show the advancements they called it the 20 series, Had noting to do with the added horse power alone or the percentage. Again I apologize...
 
Yes I know, when I buy a tractor I order the operators manual, parts book, service manuals, and tect. manuals. But the head design was taken from the engineering work that had shown up on the engine trails on the 3010-4010. They knew what bore and stroke would do for you from the GPs and the A series for torque and horse power, but for better fuel efficiency and peak or top horse power they had been working on head design since the work on the Ds in the 1930s. I didn't mean to kick a hornets nest. I read parts manuals for pleasure. And please be easy on me, I'm only a youngster of 69 years old and still learning.
 
All through their models Deere and most other company's too, have increased the power and power controls as the models changed series, and these improvements are and were on the table at least one series in advance..this was based on ways to increase sales..and to correct imperfections in design..
 
(quoted from post at 07:15:00 05/04/17) This is the first time I have heard this analogy...and your saying the same held true with the 30 series?? And this held through out all the models??

Deere never boldly proclaimed this in their advertising but they did hint at it a few times. If Deere didn't call the new model the 620 because it had about 20% more horsepower than the 60, it's a heck of a coincidence. After all they could have otherwise called it the 61, 610 or just about an infinite quantity of numbers or names.

As for the 30 series, remember they weren't even supposed to exist when the 20 series were being developed. However when it became clear that the NG tractors wouldn't be ready for 1959 the 30 series were quickly developed to fill the gap. And they were originally called the 50 series.
 
Yeah, me too. Seemed like starting out with a full forage box, it could happen pretty easy, especially if you had the engine just idling. If she shot oil out the precleaner, you better shut her down fast!!!
 
guys don,t where to start, so will just comment on the 20% BS. I worked at Deere dealer when the 20 came out never heard anything about 20% deal i think it is just BS like so much you hear but no body can back it up
 
Kent, I took it from J R Hobbs book on the 20 series, He stated it in the 520 chapter about the 520 engine test. He said he got the material from the John Deere archives among other sources. Maybe he misspoke himself or repeated untrue material, I don't know. I'll try to be more circumspect in the future. Their's one question I would like to ask you since you were their at the time. I've heard that it was stated from some dealers that they told farmers that the 620 had almost the same horse power as the 70. I never seen it in ads or sales material but heard it a couple of times when I was a kid at the time. Just wondering if you heard it as a sales pitch from any of the dealers. I apologize again for believing something I read as being true.
 
I,v been around this sales thing 58 years and most salesmen will shovel you any kind of a load that they think you will belive. make no difference what color you are looking at
 
(quoted from post at 15:56:25 05/04/17) guys don,t where to start, so will just comment on the 20% BS. I worked at Deere dealer when the 20 came out never heard anything about 20% deal i think it is just BS like so much you hear but no body can back it up

So why the 20 series?
 
Had a Maxine 237 diesel truck engine run backwards for a few seconds. Was trying to pull a severely overloaded trailer of bark out of a loading pit at a sawmill. Not anywhere near low enough gears to do the job. The endloader hooked on and that got me on solid level ground. The puff of smoke out the air cleaner was my tip-off.
 

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