Gen. Mayhem- Racing Tractor

[Doc Sprocket]

A couple months ago, I picked up a 1980 Sears LT-11 lawn tractor from a friend's father in law for $120 in running condition. I had thought to clean it up and flip it, as I had another friend that "might" be interested in it. I could have made some cash... Nah! I decided to keep it. Has an old-school charm to it.

I put a bunch of thought into what I might like to do with it. After much deliberation, I decided to build a racer. Not some backyard basher, where you just switch pulleys for speed and try not to die. No- a legit racing mower that would pass tech inspection at a sanctioned event.

I signed up at "that lawn mower racing forum" and looked around. I also looked locally for sanctioning bodies. I found a few in Ontario, all of them a few hours away from me unfortunately. I also discovered that each sanctioning body seems to have it's own build rules for classes, and even some different class designations.

I settled on SOLTRA (Southwestern Ontario Lawn Tractor Racing Association), joined their forum, and downloaded their rulebook. Due to the great distance from me, I may never race this thing at a SOLTRA-sanctioned event. I might complete it and sell it. Dunno yet. ANYHOW-

I will be building to SOLTRA's "modified" class rules. This class is pretty tame compared to many other clubs, but part of my own rule was a tight budget. Here's the machine as I got it, minus the deck (which I did get)-
(And no, I did NOT do the rattle can JD paint (great coincidence, though!)

 

[souperman000]

looks like a good start, looking forward to it. Im kinda interested in racing mowers as well.

 

[Doc Sprocket]

Factory trimmings included an 11hp Briggs flatty and a Peerless 800 5-speed transaxle. I knew the 11hp wasn't going to cut it, and I wanted to run a live axle. The rules state that the maximum engine size I can run in the class is an 18hp twin, and I MUST use a shiftable mower transmission. So- I made some phone calls...

Some time prior, I had traded my Crapsman lawn tractor to a kid I met through a Kijiji ad for some assorted crap. He was interested in building something out of it. That Crapsman had a 15hp Briggs OHV with a cast sleeve. I called him and convinced him that he wanted to build an off-roader. As such, he'd be geared low, and wouldn't need all that power. Plus, it'd be much cheaper for him to do up an offroader than a racer. I traded him my 11hp, some big tires for his frontend, a pair of offroad lights, and a couple other goodies for my faithful 15hp OHV! I'll throw in some before-and-after engine pics.

Now- the tranny- Some of you may recall that I had gotten my hands on one of those Go Kart Lawnmower jobbies in poor shape awhile back. I got it running, and was trying to figure out what to do about the mangled belt-drive system. Meantime, a buddy of mine expressed an interest in it for his young neice. I traded him the kart mower for a cherry-picker style engine hoist. I KNEW it had a Peerless 700 tranny in it, I just didn't foresee needing it!

SO, I called him, too. Long story short, I traded him an FNR gearbox from an old mower, and some much cooler tires for his kart build. In return, I got my 700 tranny back!

 

[OzFab]

This should be good

From just reading the rule book, how much work is involved to get it "up to spec"?

 

[Doc Sprocket]

I tore out the 800 transaxle, and mounted up a 1" live axle I had kicking around. I may go to a 1 1/4" axle for strength, but more on that later. I had some 3/4" wheel hubs, and modified them to 1" using some weld-on hubs from Princess Auto. Picked up a new pair of 1" flange bearing while I was there. Since I'm completely reworking my go kart, I stole the 18x8.50-8 rear tires and wheels off it, to bolt on to the new axle. While I was into the kart parts, I grabbed my old spindles, knuckles, and front wheel and tire assemblies. Cut myself a new length of 2" SHS, and mocked up a front axle, scrapping the mower axle. As per the rules, my overall width is now 42", sidewall-to-sidewall. Mounting up the new axles not only widened it significantly, but lowered it about 6".

 

[Doc Sprocket]

This should be good

From just reading the rule book, how much work is involved to get it "up to spec"?

As you would expect, steering and brakes need to be dealt with. It needs nerf bars and bumpers, a tethered kill switch, spring-return hand or foot throttle, etc.

The other half of the build is getting it competetive. Bigger engine, live axle, lowered, weight loss, geometry, gearing, etc.

 

[OzFab]

As you would expect, steering and brakes need to be dealt with. It needs nerf bars and bumpers, a tethered kill switch, spring-return hand or foot throttle, etc.

The other half of the build is getting it competetive. Bigger engine, live axle, lowered, weight loss, geometry, gearing, etc.

So, pretty standard stuff really, nothing we wouldn't do to a kart

 

[Doc Sprocket]

Exactly. The kart stuff applies well. Here's a frustration for you-

I went thru all that bolshevic getting my 15hp Briggs I/C Gold OHV back. I even installed it. THEN-

I was informed by those in the know that I needed more power to be competitive in the class. Max hp is 18, and everybody's running it. AAARRRRGGHHHH! I didn't understand. If 11hp can take my hefty kart to 72km/h, why would 15hp not be enough for my tractor?

Acceleration. Short course, tight turns. Brakes, gas, brakes, gas. DAMMIT! So- just as I was trying to figure out how my ultralow budget weedmonster was gonna survive this hiccup, I found a classified ad on the forum. Guy's selling a complete tractor, including 18hp Briggs opposed twin for $450 OBO. WAAAY over budget, but I decided to communicate. Over the course of a couple days, he dropped his price to $375, and then it came to light that he might be willing to sell just the engine. He wanted $150 for the engine and after further communication, settled on $200 for the whole thing!

Now- it ain't pretty. It never got "finished" and frankly, I'm gonna need a fresh tetanus shot before I pick it up next week! But it gets me my engine, tethered kill, rod ends and linkages, and a big fistful of potentially useful parts. Right after making the deal, I listed my 15hp on Kijiji. Within 7 minutes of posting, I was getting calls!

I sold the 15hp for $100, and I pick up the donor tractor Friday evening... Warning! Eye protection required to look at donor tractor pics!!!

 

[r97]

Guy's selling a complete tractor, including 18hp Briggs opposed twin for $450 OBO...

Settled on $200 for the whole thing!

Dang... you're good! I'm excited to see this project, it will be fun to see just how much performance you can squeeze out of that thing. Good luck!

 

[exenos]

Now that is one ugly tractor

 

[landuse]

This is going to be a good build. I have also been on the lookout for a mower. I am jealous

 

[OzFab]

Now that is one ugly tractor

At least it gets you the missing pieces of the puzzle

 

[Doc Sprocket]

That's the idea. I have another pending deal with a guy close by to me (if our schedules ever align). He's got a 1 1/4" axle with matching brake rotor and hub and a sprocket and hub. Also in the deal is a Mikuni fuel pump, a fibreglass seat, a steering wheel, and a couple of other odds and ends. Some of it may end up on the Warrior, some on my kart.

Speaking of brakes- Naturally, I'm going with juice brakes on this thing. The above-pictured parts donor has mechanical brakes (not yet sure of type), and I have another mechanical caliper. But I'm a hydro kind of guy. I have a pitbike master and caliper sitting around, as well as some motorcycle parts. I have a couple of snazzy-looking vented rotors from the pitbike, a couple motorcycle rotors, and whatever I have coming in these two deals.

Also, the donor tractor apparently comes with an RAGB. It's not allowed in the class I'm building for, so I guess it gets added to the parts bin.

Either way, not bad. As soon as I basically had a deal for $200 on the donor tractor, I listed and sold my 15hp engine for $100, so the donor's only costing me $100 out-of-pocket.

 

[Doc Sprocket]

Tore the 700 apart and cleaned it all out. Dang thing is pristine inside! Very slight wear on the ends of the shift keys, and an almost undetectably small bit of pitting on first gear. If I didn't know better (and I don't), I'd swear it has been rebuilt. It may have. I found a small trace of gasket sealant or something between the case halves, there's very little wear, and the grease was thinner than what I am used to seeing (suggesting it was both newer and replaced with a non-factory lube). I'll toss up a pic or two tomorrow.

I think I am going to soda-blast and maybe paint the case halves. I have a vent fitting for it already.

 

[Doc Sprocket]

Well- I made the deal on the Tetanus Tractor tonight- just got home in fact. I'm a little ticked off, but I still made out okay I guess.

The seller decided at some point that since I didn't "need" the wheels or RAGB, that he was going to keep them and use 'em on another project- WITHOUT TELLING ME!!! So he shows up at our designated meeting point about 40 minutes away from me, and the danged thing hasn't got any wheels, tires, or gearbox! WTF???

So I said, "We agreed on $200 for the complete tractor. This is not complete. We have to adjust the numbers, here!" He said, "Well, you were willing to pay $150 for the engine, so let's meet in the middle at $175, maybe $180." I said, "I was going to sell the gearbox to recoup some costs, and now I can't even roll the danged thing around or test drive it. I'll give you $160." He took it.

In all honesty, I showed up with $220- I was going to throw him an extra $20 for saving me two hours of driving, as a "thank you", but I was so damm annoyed that he sprung this on me without warning, I kept that $20.

So what I'm left with is the 42C.I. 18hp Briggs opposed twin, A 1" axle- stepped down to 3/4" on the ends, chain, sprocket and hub, vented kart brake rotor and hub, mechanical brake caliper, steering knuckles and spindles, steering wheel and column. The frame is junk, the seat is junk, the front axle beam is junk...

Overall, I still did well for $160, especially around here. Tomorrow, I'll wrangle the carcass out of my van and have a closer look at the goods.

Oh- one other excellent bonus- stopped by on the way home at some friends of my wife, guy runs thunder cars. We talked about my project, then says, "Here- have a seat!" Gave me an upholstered fibreglass racing seat in very good condition, freebie! He said they are not legal anymore, they have to use metal seats. He also gave me a 5-pt harness out of one of his cars. Dunno if I can use that anywhere, but I never turn down a freeb. Pic(s) tomorrow.

 

[Doc Sprocket]

Woohoo- She's a runner!

Dragged the carcass outta my van (would have been easier with wheels!!!) Plopped in a battery, threw some fuel in, checked the oil, and noticed... The choke was missing. Everything, including the choke plate itself from the carb. Common racer's trick. Meh- no problem.

Pushed the starter button, and after a few seconds to prime the line (fuel pump), she lit up nicely! Despite this thing's hideousness, there's a decent custom made 2-into-1 header, going into a collector under the running board, and she sounds NICE! I shot a quick clip on my phone, I'll have to post it.

I've got a busy day ahead of me, but as I get the time, I will start stripping the useable parts off this thang...

EDIT- I have no idea why this came out so shaky, but it gets the point across..http://www.youtube.com/watch?v=4q3w2XDY52E&feature=youtu.be

 

[OzFab]

Good news after the trouble you had getting it

 

[Doc Sprocket]

Good news after the trouble you had getting it

You betcha!
Picked up some more goodies today from a local fella- Got a 1 1/4" hollow axle, matching brake rotor and hub, aluminum wheel hubs, fibreglass kart seat, and some beautiful 8" aluminum jr dragster rear wheels. Got a couple of other miscellaneous bits, too- but the above is for this build. I guess the racing slicks are no good to me!

 

[sideways]

I guess the racing slicks are no good to me!

Would be good fun on grass though!

Keep going, I like seeing one built properly.

 

[Doc Sprocket]

I like seeing one built properly.

Then... Don't look at me! I have no idea what I'm doing on this!