Offroad big block thing built from junk

Bigblockguy

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I started building an offroad kart from stuff around my job. Got a hinged rear that im gonna add 14 or 15 inch motorcycle shocks to, custom fabbed springer spindles in the front i found the seat in the trash, reinforced it and upholstered it. 21x11-8 tires in the back and 18x9.5-8s in the front. Ill be adding an upper rail between the front and rear crossmembers tmw, and once ive got the pedals and steering figured out ill add an upper and lower with full skid plates and guards for the sprocket and brakes. Power provided by the ungoverned gx390 seen here and a 40 series torque converter.
 

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Bigblockguy

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Alright. Todays updates. I got the top rails welded on with the angle pieces in. Put what ive got so far together for the pic. Ive got shocks, spindle springs and a sprocket on order.
Anyone have any experience using 18x 9.5-8's for front wheels? My front crossmember is 21 3/4 as it sits with no spring spindles, which are gonna be about 2" out. My 40" rear axle only measures 37 1/2 outside of hub to outside of hub. I obviously want to keep the centers of the front wheels either in line or just inside the center lines of the rears while still being able to turn. Any input would be appreciated.
 

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madprofessor

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The wider the tires are on the rear, the more drag and resistance that straight axle will have when cornering. The wide front tires however, they should track well for you as long as you get proper ackermann angle set on them, and a good bit of rearward caster to straighten them out. The steeper the caster, the harder to wrestle the wheel, but you really need to have a few degrees. Personally I'd camber them in a little also, with just a little toe in. But that's just my taste.
 

Bigblockguy

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I was planning on a few degrees of each. Its hard to see but the front crossmember is cut 3.5 degrees on each side. The top of the tube is a little shorter than the bottom. My issue w turning is the 9.5 wides stand a very good chance of hitting the frame. 37 1/2 -22= 14 1/2. Split in half only gives me 7 1/2 to where hub meets wheel, and 4 1/2 of that is taken up by the tire, leaving me with only 3 inches for the wheel to turn. Less at the back of the tire bc the frame tapers in. Unless i use an offset rim, a wider rear axle, or both, this thing is only going to go fast and straight.
 

madprofessor

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Don't be watching the TV while you're running that cutoff wheel in your angle grinder. Bite the bullet, cut off everything necessary, reweld it all back with whatever extension mods you have to for clearance. Not just blabbing here, I did that very same thing to lose a homemade upside down rack and pinion setup, will post before and after pics. If you can't tweak it up or jerk it off, ya gotta cuts da mess away frum dere.
Also but not done yet, my own 8" wide tires won't fit on rear axle, it doesn't stick out far enough on either side. I'm going to cut the 1" solid axle between pillow blocks, slide it apart in both directions for a 3.5" gap, slide on a 5" piece of 1" common water pipe, and weld it up. Voila, longer axle with wide tires. Ya gots tuh bee feerluss!
 

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Bigblockguy

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Don't be watching the TV while you're running that cutoff wheel in your angle grinder. Bite the bullet, cut off everything necessary, reweld it all back with whatever extension mods you have to for clearance. Not just blabbing here, I did that very same thing to lose a homemade upside down rack and pinion setup, will post before and after pics. If you can't tweak it up or jerk it off, ya gotta cuts da mess away frum dere.
Also but not done yet, my own 8" wide tires won't fit on rear axle, it doesn't stick out far enough on either side. I'm going to cut the 1" solid axle between pillow blocks, slide it apart in both directions for a 3.5" gap, slide on a 5" piece of 1" common water pipe, and weld it up. Voila, longer axle with wide tires. Ya gots tuh bee feerluss!
Well im certainly not cutting apart the whole frame to narrow one section. The pipe fix for the axle would be a good fix until i could get a longer axle. Then its just a matter of welding on some outriggers with an extra set of hangers and bearings. I was also thinking, the front wheel i have for the mockup is offset. If i found a set like that with a 4 on 4 pattern, it may solve my clearance issues
 

madprofessor

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If you choose to do an axle stretch the way I'm going to, let me expand on my procedure................ With only 3/4" of shaft stuck into each end of the 5" long 1" I.D. water pipe, oh let's just call it a full 1" insert instead, there's room for that.................... The 1" at each end of the 1" I.D. pipe will first get sliced with a cutoff wheel in the angle grinder in a cross shape (4 slices 1" long each, spaced 90 degrees apart) for welding to the inserted axle inside.
Simple welds only of the pipe's ends around the O.D. of the solid axle would never be strong enough to not worry me, the 4 lateral slices being also welded to the axle will put my OCD to rest. Some preheating of the solid axle with my propane torch will ensure good weld penetration.
NOTE: It's a fortunate bit of luck that 1" axles slide right into 1" common screwpipe even with the internal seam (it's not DOM pipe), and the same is true of 3/4" axles into 3/4" screwpipe. I now custom cut all of my spacers for axles and jackshafts out of screwpipe, so they're not only almost free but are always just 1 piece no matter the length required, no multiples added together.
 

Bigblockguy

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If you choose to do an axle stretch the way I'm going to, let me expand on my procedure................ With only 3/4" of shaft stuck into each end of the 5" long 1" I.D. water pipe, oh let's just call it a full 1" insert instead, there's room for that.................... The 1" at each end of the 1" I.D. pipe will first get sliced with a cutoff wheel in the angle grinder in a cross shape (4 slices 1" long each, spaced 90 degrees apart) for welding to the inserted axle inside.
Simple welds only of the pipe's ends around the O.D. of the solid axle would never be strong enough to not worry me, the 4 lateral slices being also welded to the axle will put my OCD to rest. Some preheating of the solid axle with my propane torch will ensure good weld penetration.
NOTE: It's a fortunate bit of luck that 1" axles slide right into 1" common screwpipe even with the internal seam (it's not DOM pipe), and the same is true of 3/4" axles into 3/4" screwpipe. I now custom cut all of my spacers for axles and jackshafts out of screwpipe, so they're not only almost free but are always just 1 piece no matter the length required, no multiples added together.
Makes sense. I just went on bmi and looked it up. They have a 45" axles. Mines 40". They state that you may get 1" threads or 2" threads. Im gonna message them and see if they can make sure i get 1". That should give me at least 2 1/2 extra on either side to work with, or 10 inches on either side up front. If THAT doesnt fix it, ill use 18x8.5s. I cant see those not being able to turn.
 

madprofessor

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I obviously want to keep the centers of the front wheels either in line or just inside the center lines of the rears while still being able to turn.
Not really understanding why wheelbase width-matching is so important. I see reverse trikes on the road all the time, and they're extremely stable. The old school chopper trikes (even the Corvair I rode sometimes) were prone to front tire slip and/or rollover in a sharp turn, but we're only talking about inches difference here, not trikes. As far as I know, ackermann angle can be set on any differing width and still cause the path to follow exactly as set. What am I missing?
 

Bigblockguy

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Not really understanding why wheelbase width-matching is so important. I see reverse trikes on the road all the time, and they're extremely stable. The old school chopper trikes (even the Corvair I rode sometimes) were prone to front tire slip and/or rollover in a sharp turn, but we're only talking about inches difference here, not trikes. As far as I know, ackermann angle can be set on any differing width and still cause the path to follow exactly as set. What am I missing?
Aside from aesthetics? Im not an engineer, nor do i play one on tv, but ive never seen a car, or any vehicle other than a reverse trike that had the front wheels set wider than the rear ones. Moreso, i do know that old school 4x4s had the front wheels slightly inside the rear width so the tires wouldnt fall inside the same tracks. Im not sure about ackerman really coming into play with an offroad vehicle. Or how it would be accomplished on a fixed tie rod system with one pitman arm.
 

Bansil

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My 64' wants to talk :roflol:

View attachment 128942
I guessed on years, so yours is a knee knocker, hated the door openings

Sweet

So it may of been a later thing...
My 64' wants to talk :roflol:

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Sweet build!
Inter...dasting....

So....was it later, every Chevy I lifted/ built front was wider in front ,square body's and the early 70's....stuff. maybe a 4x4 Thing? My 62 was wider in front, so was '79 and '86.

Front was always wider...
 

Denny

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Dualies have a wider track with in the rear. Most other vehicles have a wider front track with in the front by an inch or so. Helps tame body roll.
 

Bigblockguy

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Welp. Everything that said it was gonna be here weds came in the mail just in time for the 3 day weekend. But at least i got my suspension stuff for tuesday.
 

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