Grass draggin' chappy Updated (3/3)

[liquidatorkid]

messed around with installing the set of ski spreaders, to lower the front end down about 1" I'm gonna have to make a spacer in place of where i have the washers stacked between the saddle and the ski spreader, as well as i noticed that one of the top leaf springs has a crack half way through it so it will need to be replaced before any test runs. i also got the teather switch mounted, and i picked up a piece of sheet alum and had my dad take it to work and bend it on the pan and break to make a new tank bracket











i did get ahold of my uncle that said i could use his old hayfeild for any testing and tuning i have to do, i figured that i would set it up for 500 ft just like the local track, and inspect the field for any woodchuck holes before making any runs


also picked up some more diamond plate alum. and a temp gauge from advance auto today to build a new dash panel, radiator bracket, the fuel shut off bracket, and the bracket that has the teather, choke, and ignition switch

[dap574]

looking nice! what about moving the spreaders to the top of skis? wish I had your energy!! Dave

[liquidatorkid]

thanks, that's what i originally wanted to do was to mount the ski spreaders to the top of the leaf springs, but because the the width of surface where the spreader mounts to the leaf spring it isn't wide enough, because the leaf spring hits against the ski spreader, and makes the ski tilted, but i am gonna see if i can get some alum flat stock to replace the washer's that i have between the saddles and the ski spreaders to make them stronger

[liquidatorkid]

i have been thinking of idea's to make chain case for my chaparral thunderbird with a 550 in it stronger, i did come across a chaincase assembly off from a firebird i believe, with the roller style chain adjuster, i have dew up a of couple of idea's on making it stronger and keeping it from tweaking and or blowing apart from the 550. i am planning on using using 3/8" thick alum flat stock to tig weld on the sides of the chain case for added support, also i would like to change the dual roller chain to a triple roller chain and sprocket set up, by making the chain case wider by using 1/4" thick and 1" wide to bend around the surface of the chain case where the cover bolts on, it would move the chain case over out at least an inch or more depending on how wide of flat stock i use, allowing me to run a triple roller chain and triple roller chain set up.

i am also planning on making a support bracket that will run from the top of the chaincase and bolt to the front cross member, as well as a support bracket that goes from the top of the chain case that bolts down to tunnel, as well as a couple support brackets that go from the steering hoop down to the bulk head made outta alum square tubing with a piece of 3/8" alum flat stock, using a u bolt to secure it to the steering hoop.

here are a couple of the drawlings that i have came up with so far







any other idea's or suggestions?

[JDT]

Maybe it would be a better idea to make a short jackshaft that had a carrier bearing on it supported by both the engine plate and the bulkhead.

There is plenty of room with the mid-mount engine and the fuel cell repostitioned.

You could use a extra jackshaft from a different sled with the same spline count and just shorten it up by 8 " or so.
A locking collar could be used to replace the secondary bolt to maintain the clutch position.

Speaking of your gas tank, 86 those zip ties and put some SS band clamps in their place.
Does crash and burn mean anything to you?

I think you will twist the stock chaincase right off with the torque from that 550 which probably puts out three times the HP as the original engine.

Where is your oil tank? Or are you running premix?

A couple of more bolts hear and there would be good like on the CDI box and the sec coil.

You sure do nice fab work. Keep it up!

[liquidatorkid]

the short jack shaft idea does make sense and I'm sure it would keep the top of the chain case assembly from twisting from either way, would it be better to use a pillow block bearing, on a bearing tower similar to that of a speedway, or build a bracket that has one of those 3 bolt bearing flanges like you would on a drive axle assembly, making it outta some 3/8" alum that mounted to the tunnel then supported down to the bulk head and to the motor mount.

i will have to look around the garage and see what i have for a jack shaft that i can cut down to make it work that has the correct size splines, O.D etc... then i can cut it down to the correct length needed and some even have a long key way on them.

as far as the zip ties, i just have them on there temporarily to hold the tank, that way i can pull it when needed to hook up the lines etc.... i am planning on going with some SS hose clamps I'm sure that they make them large enough that would wrap around the tank and mounting bracket then i can hide the adjustment screw under the tank bracket for a ice clean look.

i got talking to a guy that is pretty knowledgeable about cats, and he suggested that i could bypass the oil injection system by making it a closed loop system so i could run premix.

its funny that you say that about the ign. coil and the cdi box because i got thinking of a way to make it look better and not hacked up, i drew up a bracket that's made outta the same alum diamond plate that allows the cdi box to be mounted in the stock holes on the recoil housing, the bolts that go down through the cdi box and into the mounts on the recoil would hold the alum diamond plate as well, and the ignition coil i am planning on mounting to the plate between the cdi box, and the slide rail lube tank to give it a cleaner look

thanks, i really enjoy the challenges of building a sled like this because it allows me to incorporate different idea's thinking of different ways how it could be built. And how to make it all come together and look presentable as well

[liquidatorkid]

[liquidatorkid]

JDT here's the idea for that bearing support using a short jack shaft, a pair 3 bolt bearing flange, locking collar with (4) 3/8" bolts to secure it to the bulkhead/ motor mounts, if i built the bearing tower outta 3/8" alum flat stock and had it tig welded it would be strong enough wouldn't i would imagine? as long as i had a spacer that went between the end of the secondary and the bearing, that kept the secondary from sliding towards the bearing in the support block?

[liquidatorkid]

was able to find some parts to make the jack shaft assembly, i am using a bearing support of a 77 JD liquifire, a drive axle off from a chaparral thunderbird wide track, and i was able to match the 17t drive sprocket up with the splines on the drive axle that I'm using for the jack shaft, i have to make an alum plate that's 7" x8 to mount the bearing support to the side of the bulkhead as well as i am planning on welding up the holes that the bolts wend down through in the drive axle, as well as i have to get some spacer, and lock rings, also i am thinking about drilling out the end of the shaft where the speedo drive and and taping some threads in it so that i can tread a bolt in the end of it with a couple shims to keep it from moving as well, i have to cut a keyway in the shaft as well, only problem is i cant cut it from the splined end in to where the secondary sits because it would damage the spline's so i think my best bet would be to cut the key way just long enough for the key way that's in the secondary, as well as long enough for the brake rotor to slide on as well. i did notice that i will have to make a spacer that will move the stock brake caliper in wards to line up brake pads with the caliper or i could run a different brake set up as well on the bearing support side and fasten the caliper to the alum plat that bolts to the bulk head, here's the progress so far

[JDT]

That's the ticket L-Kid.

I have seen a similar mod done to vintage racers after the distroyed their stock cases with big engines.

[liquidatorkid]

alrighty just wanted to make sure i was on the right track. oh yeah exspecially having a cast alum chain case, i imagine that it wouldn't take too much before the would snap with a higher hp motor when they where designed for a 25hp and putting a motor that's almost 4 times that much hp something would give sooner or later, and it would be very unsafe, one of my main concerns on building the sled is safety, last thing i want is to have a clutch blow apart and injure me or anyone else for that matter, or to have anything blowapart trowing shrapanal all over, last winter i rode a friends 96 cougar 550 that was all stock besides it had an aftermarket pipe on it and had been re jetted and i was quite surprised at the power and pick up they had, and it didn't have a problem with lifting the skis that's for sure

i did look in the service manual the 96 cougar 550 weighs 525 lbs and a stock chaparral thunderbird wide track was 325lbs if i remember right, so right there is 210lbs difference between the two sleds stock, but i have removed some stuff and added some stuff as well my guess that it will be around 325-350lbs when its all done. i could save about 40lbs if i did swap out the rear suspension to an alum slide rail and added some small idler wheels along the rails, but i figured id test out the skid that i have modified and go from there. didn't, that's why i put the foot pegs on it so i can lean over the bars and try to keep the front end down as much as possible haha

[jd_decalguy]

Take all the leaf springs off except the main leaf that will help keep the nose down, also take the front bogies & mount them a little higher in the tunnel to give the track a more gradual angle. when I dragged a chap chassis back in the 70's we removed the front bogies all together & only used the back two bogie assy's. IF you have a track from a SSIII ( Part Number 51186 ) or can find one, this is the better track & will handle the HP, It has the fiberglass rods in the track.

Kenny on Chris's computer