cast alum vs cast iron

[300UGUY]

Grew up in Defiance Ohio home to General Motors Powertain plant. Cast iron engines, axles, and other auto and truck parts. Friends worked there out of high school for their entire lives in the early 1970s. Change over to all aluminum this year. Employment has gone from 3500 to 1500 people. 350 and 4.3 engines are a thing of the past.

I am retired from GM, and I have visited that plant many times. I know that back in the 90痴, it had the largest pour floor in the country, did a lot of stuff other than GM, about 1/3 of the business was non GM. And it used electric furnaces, it was reputed to account for more than 10% of GM痴 electric bill!

 

[Ivan49]

I am retired from GM, and I have visited that plant many times. I know that back in the 90ç—´, it had the largest pour floor in the country, did a lot of stuff other than GM, about 1/3 of the business was non GM. And it used electric furnaces, it was reputed to account for more than 10% of GMç—´ electric bill!

I worked for a company that made a lot of die cast machines for GM. Prince Machine

 

[Egon]

mikester: Thanks for the information.

 

[patrick_g]

Since when is a tractor supposed to be heavy?

Since Kubota started selling cast iron wheel weights and putting instructions in the user manual on liquid loading of the tires JD et al sell weights to hang on the front of the tractor, 3PH carryall used to carry heavy weights like rocks in a barrel or whatever. There are plenty of situations where optimal (or even minimally acceptable) performance is only achieved with added weight, even to an already heavy tractor. Sometimes you don't want much weight which argues for removable weight systems. Without taking a poll I couldn't say the number of tractors in use with added weight vs those run light but one indicator is the number of posts over the years here regarding adding weight rather than trying to find ways to keep it light. I'm not saying there isn't a situation where light is better but that is likely a distinct minority of cases.

Patrick

 

[LD1]

Most of the time and regarding adding weight are to counterbalance the front end loader.

Simply a heavier tractor doesn't accomplish that

 

[patrick_g]

Most of the time and regarding adding weight are to counterbalance the front end loader.

Simply a heavier tractor doesn't accomplish that

...and why does JD and others sell weights to hang on the front of the tractor? Not likely to aid FEL use. Actually a heavier tractor with balanced fore-aft weight distribution will permit heavier FEL loads than a balanced tractor of lighter weight. I agree, of course that adding weight toward the rear of the tractor helps with FEL stability. A heavy 3PH mounted implement does wonders for FEL stability. I sometimes use my 1700 lb box blade for such a counterweight.

Patrick

 

[LD1]

Seriously......

I am beginning to wonder about these questions.

Front weights counter heavy stuff in the rear.

I could ask why they even sell turf tires, I don't need them and never will. But that's not the point. I know what turfs are for, and that they benefit some.

Same with weights.....front or rear.

 

[Ivan49]

Seriously......

I am beginning to wonder about these questions.

Front weights counter heavy stuff in the rear.

I could ask why they even sell turf tires, I don't need them and never will. But that's not the point. I know what turfs are for, and that they benefit some.

Same with weights.....front or rear.

I guess it OK if all you use your tractor for is mowing or running around the yard. I took the loader off mine and even with the rear tires loaded it was worthless in the soft ground

 

[goeduck]

I guess it OK if all you use your tractor for is mowing or running around the yard. I took the loader off mine and even with the rear tires loaded it was worthless in the soft ground

I get around my fields with unloaded turf tires on one of my tractors on my soft ground. No lawn on the property, otherwise it would get around on it as well.

 

[patrick_g]

How does a heavier tractor handle a FEL better than a light tractor? This is with no added weights to either machine. In the general case the center of gravity (CG) of a tractor, is roughly in the same place whether a light or heavy tractor. There are two lever arms of interest: 1. A lever arm from the CG of the loader bucket to the front axle and 2. from the front axle to the CG of the tractor. Just to keep the math simple let us say the loader lever is one unit in length and the lever from the axle to the tractor's CG is also one unit in length.

Too much weight in the bucket and the rear tires go up in the air instead of the bucket going up when the joystick commands the FEL to lift.

In the above simple example if more weight is placed in the bucket than the tractor's weight the rear wheels will go up instead of the bucket. In the real world part of the tractor is in front of the front axle which detracts from loader max capacity. Also in the real world the two lever arms are likely to not be the same length. I'll take a couple cases to illustrate the above point regarding lever length. If the loader lever is 1/2 the length of the tractor's lever then the loader limit would be twice the weight of the tractor (assumes no tractor weight forward of the front axle, not so in the real world but just trying to keep the example simple.) If the tractor lever was 1/2 the length of the loader lever then the max loader lift would be 1/2 the tractor weight.

For the above examples let us consider what the weight of the tractor would be if our imaginary scales were placed under the CG of the tractor. This is the weight of the tractor used in the above examples. We also assume for the above examples that we have sufficient hydraulics to lift anything and are limited by tractor weight not hydraulics.

Clearly, a heavier tractor could lift more than a light tractor. So what do we do to increase our max FEL lift weight? Add weight to the tractor behind the front axle, the farther back the better. A brush hog sticking out the back will have a long lever arm. Its lever will be the distance from the front axle to the CG of the brush hog.

I have three sets of cast iron wheel weights (max Kubota allows under their warranty) on my rear wheels and they help but... if I have a 800-1000 lb round bale on the bale spear (mounted in place of the bucket) I have trouble keeping the rear wheels on the ground. So, I either put my 3PH bale spear on and carry a bale in back for ballast or use a heavy implement on the 3PH (box blade or brush hog.) What this does is shift the tractor's CG back farther from the fulcrum (front axle.)

Given two tractors of the same size with equal loader installations (neither with accessory weights or loaded tires) but with one tractor heavier than the other, the heavier tractor will be able to pick up a heavier FEL bucket weight. If the lighter tractor has sufficient hydraulics then adding weight behind the front axle (the farther the better) might give the lighter tractor significantly more FEL lift capability than the heavy tractor (My case with my Kubota as it out performs many of my neighbor's heavier and more powerful engined tractors as it has powerful hydraulics and I put a HD 6 ft brush hog on the 3PH for a counterweight.)

Patrick