Heymow - Lawnmower Racing Forum
Mower Building / Setup Help => Project Builds => Racing Mower Builds => Topic started by: DeereRacer on July 04, 2012, 12:21:02 am
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I purchased a 1979 John Deere 65 off of ebay a few years ago with intentions of making a racer out of it and now I am finally getting to it. I got it tore down to a bare frame and started cutting excess brackets and metal off it.
(http://img220.imageshack.us/img220/828/my65.jpg) (http://img137.imageshack.us/img137/5509/20120703090133348.jpg)
(http://img607.imageshack.us/img607/6620/2012070309022197.jpg) (http://img535.imageshack.us/img535/2466/20120703090339812.jpg)
(http://img688.imageshack.us/img688/9967/20120703122417500.jpg)
I have a few things that are worrying me about the build at the moment. The engine crank shaft and rear axle are going to be in real close proximity to each other. With some rough measurements the 13X6.50-6 Turf savers I plan on running will put the rear axle right in the middle of the 4" tall frame with the frame 4" off the ground. Because of this I will have to run the engine drive pulley under the rear axle about 3" down the crank shaft from the bottom of the engine. I will also have to lower the trans to line up the belt but that is a good thing because it will give me more room to lower the seat after I give the engine a 90* turn to the left. Do you guys think the pulley sitting that far out on the end of the crank shaft will cause any issues?
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Unless your rules say you can alter the wheelbase, it has to be in the stock position.
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Doesnt sound to me like he is altering the wheel base. He just wants to know if there will be any problems running the pulley that low on the engine.
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Doesnt sound to me like he is altering the wheel base. He just wants to know if there will be any problems running the pulley that low on the engine.
I think I have sunburned my brain. Not many run rear engine riders, you will have to
invent alot of what you want to do, and trial and error your racer. Anything is possible
with that pulley out that far. I personally do not know anyone running a rear engine mower.
Would it work with the pulley on the end of the crank, yes, as long as it bolts on. Will
it stay for a while, not sure how long. There will be more pressure on the seal and the
case due to the leverage. A third bearing support comes to mind.
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I realize the rear engine platform is not ideal but Deere never made a mid engine mower or even a light weight front engine but I like a challenge and it will be different. If I were to cut an 1" off the bottom of the frame I could then move my axle higher in the frame and still be at 4" height plus i would be able to move the pulley closer to the engine the same amount. If the frame was cut neatly it wouldn't even be noticeable but would the rules allow it?
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We cut projections off the mowers from time to time. The key word is discrete.
So long as the line is even all around, that would be ok. On all the MTD mowers
that have a lip in the front, we have to cut that off, and a few on the back.
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The problem with that platform is the first thing to the wreck is your feet the second thing is your man pride wrapping around the steering column. Thats not to say they cannot be made to run and handle but its gonna be a chore.
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what would happen if you sucked the pulley right up to the bottom of the engine pan. is there room for the belt to travel above the axle?
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I built one rer for a guy and never again haha. What a pain. Although I like this jd 65
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what would happen if you sucked the pulley right up to the bottom of the engine pan. is there room for the belt to travel above the axle?
That could work though I would have to move the axle to clear the pulley and that would raise the rear. It would also raise my planed lower seat height becouse it sits over the transmission. This build is geting more complicated than I though it would be but thanks for all the comments guys.
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its not set in stone that you must have your ride hieght at 4 inches. a little higher would not hurt so you can clear the axle.
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i would rather sacrifice an inch in ride height in order to have the pulley closer to the engine and not have that extra force on the crank
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i would devise a plan to have both,
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i would devise a plan to have both,
An inch higher ride height AND the pulley all the way out on the shaft??? :lol: :rofl:
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An inch higher ride height AND the pulley all the way out on the shaft??? :lol: :rofl:
very funny coming from the one armed bandit.
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(http://img717.imageshack.us/img717/8442/20120717161901291.jpg)
Well I have decided to risk it an run the pulley on the end of the crank. The stock mower deck drive pulley hung about 4" off the end and that worked. Though that was a slightly lower rpm :lol:. I got the frame notched out for the axle today and mounted the rims and hubs to it to give me an idea how it is all going to lay out. I am defiantly going to have to modify the running boards for clearance when turning and I will not be able to lower the steering column at all. I need the height for my knees. (http://imageshack.us/photo/my-images/717/20120717161901291.jpg/)
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I ran my Modx with the pulley almost at the end of the crank on my Tecumseh all last season. No troubles to speak of and motor is back together now still turning 6000 or so.
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John Vinka or Chuk Miller might be able to give you some tips on a rear engine rider. They we're about the only 2 people that I remember having much sucess with that platform. Vinka ran a ariens and not sure what the boggie woogie that chuck ran started out as
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Chucks was set up for a GX390 so it is all horizontal. Vinka has an 820 under his, but if memory serves right it is up in the air a little ways, but he makes it fly!
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Now the farm field work is coming to an end for the season I can now start to put some thought into my rear engine racer again. I am thinking about doing an aluminum sub-frame. My plan is to run either aluminum channel or angle from axle to on the inside of the frame with an aluminum trans plate attached to the the top of that, angle aluminum seat frame and a square tube double X-brace from the front axle to the seat frame. You can get a rough idea what I am talking about in the picture.
(http://img835.imageshack.us/img835/6018/65subframe.png) (http://imageshack.us/photo/my-images/835/65subframe.png/)
Has anybody ever attempted aluminum bracing before? My one concern is that the welds will crack in the beating it will get on the rougher tracks.
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Depends how thick the aluminum is. The fenders our our semis crack a couple times a year. Granted they're only 1/8"
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I have 2"x2" aluminum angle that I have used to reinforce the frame on my mod-x-r and it works great it is approx. 3/8" thick. I have it welded but it is also bolted to the main pan frame. It is very stiff and is light weight. Here is a couple of pictures. The first one is of the frame and the second is of the dash support.
(http://i1056.photobucket.com/albums/t379/conductor_81/th_CIMG0108.jpg)
(http://i1056.photobucket.com/albums/t379/conductor_81/th_CIMG0331.jpg)
Hope this helps.
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I made Scotts rear engine rider with big tires for back and small in front all it did was wheelies. It was also very sketchy going around the corners cause it keeped leaning and stuff. It had 10.5 brigs flathead in it. With i think 8inch on engine and 2inch pully on tranny. It has a mtd junky tranny but some how from all wheelies we did stuff it still runs like a champ. We keeped the pullys in the same spot though and how belt was set up to. Only thing ill be worried about that rear engine racer is my you know what hitting the steering support or me flipping off the back hitting a bump or something. Even though i built mini and it dose wheelies, I feel much safer on it then the rear engine rider even though they look fast when they race like england and stuff.
Just what ever you do dont try driving up the back of the truck on ramps with it. My freind learn then hard way lol it was really funny cause he asked me to help as he got stuck at top of it and slowly falling on him, as i was laughing so hard. It flipt on top of him and he learn why not to do it quick lol.
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Hey looks like you have an interesting project on your hands.... i have a few questions about it. You are running 13's on the back instead of 16? Also what engine are you planning on using? Also i used to have an s82 that looked very similar to yours except the rear hada "hood" over the engine and tires. Your looks diffferent in that area. There is no rear "hood"over for yours?
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Just make sure your seat is well strengthed because mine broke its mount and hit the fly wheel shroud and poted the dip stick off alot and oil sprays all over lol.
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Hey looks like you have an interesting project on your hands.... i have a few questions about it. You are running 13's on the back instead of 16? Also what engine are you planning on using? Also i used to have an s82 that looked very similar to yours except the rear hada "hood" over the engine and tires. Your looks diffferent in that area. There is no rear "hood"over for yours?
A Friend of mine is also building a S82 http://www.heymow.com/index.php?topic=20668.0 (http://www.heymow.com/index.php?topic=20668.0) . They look similar but I think the only part they share is the steering column support. As for the rear tires yes they are 13" they are also only 5" wide wanted to make sure I would not have wheelie problems like Darkviper mentioned. I figure If I don't have enough traction I can always step up to the 6.50" wide tires. As for the the hood the model 65 and the older 55 never had them. Interesting thing about the 55 is it had handlebars and rear bumper otherwise nearly identical on the outside.
I have 2"x2" aluminum angle that I have used to reinforce the frame on my mod-x-r and it works great it is approx. 3/8" thick. I have it welded but it is also bolted to the main pan frame. It is very stiff and is light weight. Here is a couple of pictures. The first one is of the frame and the second is of the dash support.
I was thinking using 1.5"x1.5" aluminum angle 1/4" thick. Maybe that will not be enough.
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I actually have a john deere r72 that I was planning on turning into a a/p racer. My frame is a wedge like the front is 12" wide the rear is 15" those aren't the really measurement just a example. It's weird never seen one like it. It just more :bash:
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Queston is where would u race them besides Uslmr?
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The US Open series, or locally. Maybe with ModX if you had to.
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A Friend of mine is also building a S82 http://www.heymow.com/index.php?topic=20668.0 (http://www.heymow.com/index.php?topic=20668.0) . They look similar but I think the only part they share is the steering column support. As for the rear tires yes they are 13" they are also only 5" wide wanted to make sure I would not have wheelie problems like Darkviper mentioned. I figure If I don't have enough traction I can always step up to the 6.50" wide tires. As for the the hood the model 65 and the older 55 never had them. Interesting thing about the 55 is it had handlebars and rear bumper otherwise nearly identical on the outside.
I was thinking using 1.5"x1.5" aluminum angle 1/4" thick. Maybe that will not be enough.
It may be enough I just happen to get a great deal on the aluminum I used. It is stiff and it hasnt cracked yet.
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it'd make a cool little fx
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anyone know if this project ever got finished?
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Nope, sitting in the back of the shed. I hope to get back at it this winter but I think I will make a GP out instead.