Designing a Corvair Custom Hydraulic Tractor

[kude]

Not to be rude by any means. Life is way to short for that stuff.

I have owned a few - they are safe!

Have you even owned one?

There have been many other books showing the newer findings long after that book.

Even the government stated that it was safe - years after the book you speak of was released.

Just like with a wil - it is the last one that counts!!! :laughing:

More times then not it's the driver behind the wheel of any car - one ton - two ton - ford - cehvy - that makes a car unsafe while driving....

Just like humans - all cars have their limitions...

Have you seen a corvair road race and tear up the track and other race cars?

Videos all over showing such stuff. :thumbsup:

BTW - Did you even read the thread or just the title?

I know people to this day who hear the word Amway - first thing out of their mouth - it is a pyramid scheme and against the law.

ODD how the US government after years and years of trying to find something wrong with Amway - stated that it was one of, if not, the only business like it that was not illegal. However, people still bad mouth it to this day. It's a part of life!

I only learned the true about it --as part of my college business class.


I hope you learn the truth about alot of things... and don't assume...or simply post stuff to stir things up.

Have a great day and good luck.

I just asked if you had read the book. I realize Ralph Nader just used the Corvair to push auto safety in general and make a few bucks from the book.

I had a girlfriend that loved her Corvair until the front hood popped off almost getting her killed. Other than than that I thought the later ones were nicely styled.

It's funny how testy people are to reactions to their posts.

 

[LBrown59]

Welcome, and we want pictures...lots of pictures.

Yep pictures and more pictures.

 

[KWentling]

I'm looking into purchasing this New Holland TW20 Cab in the picture.
However, I like to see the size of the full tractor, with this platform, before I fully comit to the purchase.

Doing searches for used TW20 for sale; I have not been able to find anything like the one
Thanks, Tony[/QUOTE]

Can't tell you for sure if that is an open station TW 20 or not, but if it is, that is from about a 130 HP ag tractor. I think that is bigger than what you are looking for. I would guess outside to outside width of the fenders would be around 6 or 7'. The steering wheel would have been about 7' from the ground. You can look up tractor models at Tractorhouse.com to see what they look like and going prices. They also have listings of tractors being parted out that might be of interest. I'm in the camp that you need to find a hydrostatic tractor to repower with your Corvair engine. A lot of design and engineering go into something like that, and not saying it can't be done, but I think you would save money and frustration by starting with a hydrostatic transmission from a proven platform.

Kim

 

[o2batsea]

Deutz (germany) tractors use an air cooled Engine. I don't know whether they have hydrostatic models nowadays but my guess is yes. You might take a look at how they build for some ideas.

 

[Ford tractor]

That "Unsafe at any Speed" was one of the biggest hoax's ever put onto the American Public. Very unfortunate, but typical of our American Way.

Yeah it was a fraud put out to enhance a political agenda. Just like Al Gore admitted to about corn ethanol -- he supported it JUST for potential personal gain. But he would NEVER EVER do that about global warming to make himself $100 million dollars! .... would he? (Only in a heart beat)


Big pump is needed for the project. Here's one that matches the engine power.

https://www.surpluscenter.com/item.asp?item=9-6557&catname=hydraulic

It will take 120 hp at full pressure and full flow.

Then get 2 of these for the rear wheels

https://www.surpluscenter.com/item.asp?item=9-072-1040&catname=hydraulic

Talk to your local hydraulic guy oh how to plumb them so that you can have differential action or locked on demand. (I know it can be done, but ferget how to plumb it up !)

Then get a hydraulic control valve that can handle the 50gpm, set the pressure to 3000 psi and go.

Probably will need to get a variable flow divider that splits off up to 25 gph to power a 3pt lift, loader, power steering or other applications that need a hydraulic motor. I can imagine a front mount mower deck, front mount snow blower, etc powered by hydraulics.

With your 2 to 2.5x hydraulic volume you are going to need a 100-125 gal tank. You knew that, right? I would have thought that 30-50 gal was fine. As reservoir volume goes down, cooling requirements go up so you get to balance between the two.

 

[Kernopelli]

There have been two home made tractors by TBN members that stand out in my mind. One using a Suzuki 4x4 platform, the other...I don't recall but was the more recent project...both excellent builds by very talented fabricators but neither fully finished to my knowledge/recollection. It is a really ambitious undertaking...lots of design time, fabrication skills, Fab time and money. I know the fun is in making something from scratch but the reality of a project like this is you can ( not always buy needs to be considered a real possibility) that you spend twice as much on something half as functional as an old used factory machine. I think Hooked on HP is right on. Find a donor machine w/ bad motor work on an engine swap. I think you will end up with less expense and time in the machine and possibly ( probably) with something more functional.

Mossroad makes some really good points and gives good insight into what building a hydro machine is going to take. Hydraulics can become pretty complicated and require a good understanding of what you need, how it works and how to put it all together as a functioning package. Hydraulics are expensive. Do I think that a person can bargain shop/auction hunt/salvage and get what they need at greatly reduced cost? Yes...it also involves a lot of time, patience,luck and knowing what you are looking for. I'm not trying to say this can't be done or that you shouldn't be even be considering it.....just saying, it isn't as easy as it sounds like it should be.

That TW 20 is considerably larger than I thought you were looking for. I was thinking that somewhere in your posts you had mentioned large garden tractor/small compact tractor size machine (?)...the TW20 is a 130 HP os so, 12,000lbs tractor that probably rolls on 18 X 38" rear tires ( think tires as tall as your wife)...the cab is proportioned to these size components and weight. Try google images or tractorhouse.com, youtube ,etc and see if you can find some pics of one to give you an idea of size.

Have you given a gear drive any consideration? I know you have mentioned that a foot clutch is out but a hand clutch ( popular on some antique tractors)or a hydraulically actuated clutch would be simple enough and would certainly broaden the possibilities for the build greatly.I don't recall ever seeing a hydraulic set up on a tractor buy I can't think of a reason why it wouldn't be easy to do or why a responsive system wouldn't allow typical use....quick engagement/disengagement, slipping, etc. Most gear drive tractors also are set up from the factory with both a foot throttle and a lever throttle which would satisfy the needs you described earlier. High flow auxiliary hydraulics can also be added with PTO pumps or other forms at "reasonable" expense if needed if the tractors standard system is not sufficient for your needs.

 

[CorvairGuy]

Thanks: KWentling, o2batsea, Ford Tractor and Kernopelli.

I'd love to be able to go see the used tractors. I can only find them online. And the only places I can see them online is in the USA. So Far I have not found a place in Ontario close to Ottawa that has a tractor junk yard so to speak.

I even called a few local dealers to see if they took in, as trade, any tractors needing an engine, trans or some big repair. NO such luck!!

So it is hard to tell what size some of these are in a picture.

BTW - If any of you hav enot guessed yet - I'm a city boy - not a country boy - I know nothing about tractors.

IF ANYONE knows of an old style good size GARDEN tractor - that will allow the stock or cutom attachments I want to be add - PLEASE point me to some info and pics. I'm interested in the sheet metal work and style.

Also IF you should come across a newer complete Larger size GARDEN tractor - like most are stating - that needs an engine - PLEASE post a link here.

Whatever I end up getting, I want to be able to get on and off easily or in and out when I build a cab.

Thanks, Tony

 

[Redneck in training]

Tractors use single pump and single hydraulic motor because they use also gearbox with two or three ranges. Reason being that the maximum torque and rpm of the motor are not infinite.
I forgot to mention that for effective usage of the hydrostatic propulsion you have to have a speed governor on the engine. The hydraulic system will vary load on the engine in great range. You have to maintain constant rpm not only for life of the engine but mainly for proper function of the driven implements. Also consider mass of the tractor. Looking at specks of the tractors on the market you need in average about 100 lb/HP for effective pulling power.
I would like to add, as someone already suggested, that you should look for used tractor with a bad engine or cheap Chinese tractor and replace the engine with Corvair. That is if you need a tractor. If you enjoy the process of building it (and have money to blow) go for the full build. Possible source of pumps, hydraulic controls and motors are also combines. I was just involved in repair of a combine few weeks ago. The reduction gear, brake and wheel hub come in one unit easily removable from the frame. Motor stays bolted in the frame and connects to the reduction gear by short shaft.
Here is a link for inspiration:
Struck Corp; Magnatrac? Compact Crawler Tractors

 

[Kernopelli]

Do you have a local junk yard/metal recycler. Our local guy will usually put push mowers, motorcycles/atvs, lawn tractors, garden tractors, tractors etc. aside to be sold separately. If they don't sell after awhile, he'll crush them but he generally has a few sitting around. I'd also look on your closest craigslist, if nothing is available for sale, place a want ad for one.

Here's a pic of a junk yard project my 17 yr old son built entirely by himself when he was 11 yrs old...welding, paint, designed the clutch,etc. He bought a Snapper electric start push mower out of the scrap yard mower pile for $7. The wagon for $5 and he had the rest left from a lawn tractor he had bought from the junk yard mower pile for a previous project for $25. He did use some of my scrap metal.....I loved that thing and it ran like a top too! You can probably tell but I'm still proud of that one!

 

[brokenot]

You can use standard cruise control for speed governor

Cruise controls make for a very rudimentary and only semi-effective speed control. It's difficult to explain, (and probably understand), but for a cruise control to work effectively, it would need to be much more responsive than it is. When set up for whatever car or light truck application it's in, it has parameters built-in that don't simply allow it to try and maintain a constant speed via monitoring rpm, it also tries to do so within a set of "behavior" parameters. How quickly it recognizes and responds to changes, how quickly it actually changes the throttle positioning, (both in throttling up and down), etc. are some of the variables considered.

Back in my first governor post, I mentioned how the electronic governors we use, (one manufacturer being Precision Governors), do not have a "one size fits all" model for spark ignition engines. They have several models. Each of those models has a "range" it's designed to operate in, once the application is made known to the manufacturer. Then they build the governor and ship them out to the end-user with a set of instructions as to adjusting it. It's pretty rare to take one out of the box and install it without having to tune it's performance via the trimpots. One setting that pretty much always needs tweaking is the "gain" setting. Too much gain one way causes the engine to bog because it isn't responding quickly enough, and too much gain the other way causes a lot of surging under smaller changes in engine load, because it's responding too quickly, overshooting it's target, then backing off....and then undershooting, etc.

It would be just as rare to install a simple cruise control and have it provide the functionality you're looking for. The problem there lies in the fact that you can't open up the back of the cruise control and tune it in for your particular application. You're stuck with whatever it dishes out.