What to use for a garden tractor puller??

In a couple of years, my son will be able to compete in the 4H garden tractor pulls, and I was wondering what AC tractor would be good for this.  Right now, all that I know is that it must be under 20HP.  Just wondering if anyone has any experience with this?  All my experience is with modified farm stock and pro stock tractors!!  Thanks.

My son used to pull a B12 with an 8" pulley on the trans.  He's 36 now ,but I can still remember the grin the first time he beat those JDs & cub cadets.  something about the way those old cast iron Briggs pull & lug down. Note on those ol Briggs leave the points, the electronic ign. goes away at low rpms. Cal in Ct 

The AC 620 and 720 are conservatively rated at 19.5 hp.  Are hydrostats allowed though?  At 1300 pounds they've got the weight you need!

I've got a Simplicity 3415 S I need to get rid of. Anyone interrested?

Regardless of the tractor pull, the winner is always the sled, and the determining factor is the rules.  The Wismer-Luth agricultural tractive effort prediction boils down to ratios-  weight of the tractor, proportion of weight between driven and undriven wheels, and the diameter of the driven wheels.  Once the wheel starts to slip, the amount of drawbar effort available rises in very small increments with addition of large amounts of horsepower.

SO... regardless of what you use in pulling, weight is a key factor, hence GT pulling is usually categorized by weight class.  Don't take a knife to a gunfight- make sure your machine weighs in at the maximum allowed, and keep that weight under control.

As Jeff noted, garden tractor drivetrain weaknesses are usually the biggest issue.  Many manufacturers used belt drives and lightweight transaxle assemblies, oftentimes wet clutches buried inside an aluminum housing... many Peerless transaxles are that way.  The defining feature of true 'Garden tractors', are that they're intended, from the git-go, for 'ground engaging implements'... this means tractor-pulling was part of the intent... mebbie not against a sled, but against a plow.  Serious garden tractors have heavy drivelines, strong axle tubes and shafts, stout clutches, and engines that live long and develop high torque.  Easy way to find these guys-  pick up the back half.  If you can lift it, it's not stout enough.

EVERY type of driveline has it's limitations.  Using a belt-driveline system usually defines your power limit very early.  The maximum amount of power transmittable by a belt is determined by the belt shape, tension, and amount of tractive surface on the belt... aka 'wrap' surface.  There's plenty of good information out there, and Carlisle has a belt selection program that will identify the maximum amount of power that a belt can reliably carry... if you plug in the numbers for a variety of common setups, you'll find that shaft-driven drivelines have a distinct advantage over belts. 

Hydrostatic drivetrains, although very capable, tend not to be used for competition, because the hydrostat is horsepower-lossy in comparison to gear-drives.  Most rule-books will have some stipulation that once the hydrostat speed has been selected, it cannot be changed, so running a hydro puts you at a disadvantage.

I haven't seen many incidences where a belt-driven machine out-pulls a shaft-driven, but where they did, it was simply a matter of operator skill.  I've also seen many pulling tractors that wore one company's colors, but had a Cub Cadet gear-drive rearend.  Why?  Because the Cub Cadet rearend is the same as that used in the Farmall Cub... right out of a genuine farm tractor... heavy iron, oftentimes fitted with a ring-and-pinion out of a Dodge Dart, and fine-spline axleshafts... there simply aren't any other 'stock' rearends out there that come close.

Kohler K-series motors appear to dominate stock classes, and if you like to 'work' on your engine, and the rules allow, the 'small' 12hp engine frequently responds best to modification... it will typically survive best making much more power than the 14 and 16hp blocks, albeit you'll have a special head, crank, and flywheel, very high governed RPM, velocity stack, and all sorts of other crazy things... and when you get it 'right', the dyno will be up around 45hp or so... (and your wallet will be really, really empty).

But if you concentrate on the concept that it's supposed to be FUN... pull what 'ya brung, and ignore what the other guys do... look at the track, hitch up, wait for the flag, and when it's time, realize that it's you against the track, and the sled ALWAYS wins.  At the end of the day, if you come home with mud in your hair and a smile on your face, you did it right.

I have a 716 that is set up for pulling just needs a motor if anybody is interested let me know and i will get you the information on it. thanks nathan

I used a Cub 1811 (hydro) to mow for 20 years with no issues.

Is the. B110 the same as a simplicity 2210, I thought it was but I have a 10 hp briggs

guys that run the AC's (simplicity) in the B series or the 700 series  take out the bevel gear box and replace with a superior or other right angle gear box, use pulleys with a c belt as stated above on a gear drive unit and replace the rear axle with a solid shaft. Local rules may not let this be done.  Stock trannys are only good for about 25 -30 hp long term.   If one wants to show the colors, there are web sites that specialize in cub cadet special built tannys, clutches and axles - these will last and ac be put under what ever sheet metal you choose. .

I've seen a Panzer at a show, but never on a pulling track, so I couldn't tell you what to expect, but the smaller automotive differentials, where allowed, are prevalent in any application where they'll fit.  Typically, you're getting a stronger carrier.

Dream- that Sears unit was definately a tough bugger, and the OHV Tecumseh was, in many ways, ahead of it's time... I have same engine on my Miller Bluestar welder.

It ALWAYS comes down to rules... no matter what the situation, it's all about the rules... and there's two rules about rules:

You can't win if you're caught and disqualified for breaking the rules...
and
You can't win if you don't push the very limits of the rules.

And while I've been known to hook up to a sled with both garden AND full-sized tractors every once'n'a while, I've never done competetive pulling.  I've built a tractors for doing draft work, pulling trees, locomotives and railcars, wierd implements, and other purposes, but not for competetive pulling, never hooked up to a sled for any reason other than being able to put a machine under a load, and try my hand at beating the track, and the sled...  and of course, the sled beat me every time.  ;-)

Good-
Do to the airflow being lousy, cast-iron (square-end) factory mower decks are poor by modern standards, but they were incredibly tough and effective for their time.  Later stamped-steel decks are substantially better, but metal had to be thinner and softer to accomodate the stamping process.  They're still stouter, thicker decks than most others of the time.  During the early '70's (before the stamped decks came about), the best deck designs came from companies that made fareway mowers... the big Toro, Howard Price, Woods.  Once airflow concepts trickled to the home market, that all changed... I think the big commercial Simplicities really started the wave, and Gravely really pushed it into the consumer market.

The Cub Cadet hydrostat driveline's biggest weakness is the cross-pin on the engine drive coupler.  Gear drive's biggest weakness is again a pin on either the clutch drive or gearbox end.  Many guys, not knowing, replace these pins with conventional roll-pins, when they NEED to be a Spi-Rol pin (a piece of high-tenstile spring steel with several turns wrapped into a pin), hence, the engine's power shears them readily, tearing up the shaft and bore for future problems.  Note that the spi-rol issue shows up in MANY garden-tractor applications, so this problem isn't limited to any one brand of GT, and extends to implements as well.  It is also more prevalent in high service-factor, high-power/high-traction applications, so larger single-cylinder engines will break them faster than even larger-displacement multi-cylinder engines.  Must guys either correct them properly, or use industrial U-joints.  My IHCC loader runs SKF U-joints and hardened pins for that reason.

Steering slop is the result of lots of use, and eventually proves to be a limiting factor of steering angle.  Many garden tractors of the vintage used the same ROSS worm-sector steering system, and all used tie-rods and drag links.  Careful inspection, proper rebuild, repair, and adjustment solve most of those problems.  The converse, is siezed components, which is either caused by no use or maintenance, or use of incompatible greases in fittings.  Mixing lithium, sodium, or molybdenum greases results in saponification- greases ionically recombinding to form something akin to 'stone'.  This is typically followed by somone 'forcing' the steering, and causing damage to other innocent components.

As for being good for 'only pulling', that's a statement made of passion, not logic or experience.  All garden tractors intended for 'ground-engaging implements' have many uses... they are, after all, built with the intention of being worked hard.  I have a Johnson Workhorse loader on my 'mutt', and there are some pretty substantial hand-fabricated parts and a whole lotta ballast to make it pick and carry 500lbs, but the transaxle and frame is actually bone-stock.

It's a shame, but suffice to say that nowdays, most products are made to be 'sold' rather than worked... and while prevalent today, that same concept DID exist 30 years ago.  In all cases, it's all a matter of picking the proper tool for the job, and realizing that tool's limitations.  Likewise, when doing competetive pulling, it is particularly necessary to know those limitations, as you WILL find 'em... because if you don't, you won't be competetive.


Edited by DaveKamp - 08 May 2010 at 11:43am

As another posted, find a manual transmission-----not a hydro.  Too much power loss.

Then read the rules carefully.  If 2 cylinder engines are allowed (or allowed in some classes) try and find an Allis 920 or Simplicity 7790.  These were only made in 1984 and 1985 and had a 2-cylinder Lombardini diesel engine.  It was conservatively rated at 18+ hp.  But it has an injection pump that can be adjusted (big smiley).

Find a gear drive 916 to start with and learn the driving, tire and weighting tricks and then swap the diesel into it.


Edited by 427435 - 31 Dec 2010 at 11:31pm

I have a rather old Simplicity for sale. I'm in Florida for the winter and not 100% but I think it's a 3114 4 speed Shuttle, single cylinder Briggs engine.

Interesting thread before my time on the forum, I always wanted to know if anyone pulled a 720 before. At 1,300 lbs I always thought they would be stout since I feel they are built very well even though they were a hydro. Even if limited to a single speed, 1st gear in full forward hydro should produce some good power IMO.

The old MTD garden tractors with the drive shaft and the fiber clutch would seem to be a good choice,also the small Bush Hog garden tractors with  basically the same set would be good.I've run both and never slipped the clutch  on either.