Engine mounting issue

[WillMatrix]

Hey guys long time no post

I have a predator 212 and a torque converter that I would like to mount on my mini bike. My problem is the torque converter back plate won't clear the engine or frame because of it sitting to low. Do you guys have a idea of an easy way for me to raise my engine?

 

[Denny]

2” spacer blocks. Made out of solid aluminum (expensive). 2” steel square tubing with at least a 3/16” wall.
Hows that for an answer?

 

[WillMatrix]

2” spacer blocks. Made out of solid aluminum (expensive). 2” steel square tubing with at least a 3/16” wall.
Hows that for an answer?

Perfect. I was having a brain fart moment. I only have 11 guage will that be good enough?

 

[WillMatrix]

2” spacer blocks. Made out of solid aluminum (expensive). 2” steel square tubing with at least a 3/16” wall.
Hows that for an answer?

Will I damage the integrity of the TC if I cut about a inch off the bottom of the back plate?

 

[Denny]

11 gauge will be too thin. And 1” is a lot of metal to remove from the back plate in my opinion. Your mileage may vary. Objects in mirror may be closer than they appear. May not be available everywhere. Dealer delivery and prep may be additional.

 

[madprofessor]

11 gauge will be too thin.

I must disagree, my 520# kart is built from 1.5" square 11 gauge steel, and is bulletproof, stiff as Biff.
Look at the parts of the backplate that actually connect to anything.............that's the 4 bolts that pin it up against the engine, and the built-in jackshaft. You can cut away any part of the backplate that wouldn't increase torque on those parts beyond what it would take to snap the potmetal backplate, people do it all the time for clearancing. Leave as many "ribs" as possible.
NOTE: A separate jackshaft mounted to the frame eliminates the need for any backplate at all.

 

[karl]

A 5/16-18 bolt will collapse 11 gauge tubing .

So thin wall tubing is not ideal to use as a motor mount spacer if you wish to securely bolt down the
motor. I learned this lesson the hard way about 7 years ago. Thicker wall the better.

It can work fine as frame rail , then weld on tabs/ plates to mount the axle-motor ect,
but you don't want to sink the bolts straight though the tubing, where
its clamp load compromises the integrity of the tubing.

 

[madprofessor]

A 5/16-18 bolt will collapse 11 gauge tubing .

Absolutely correct, if torqued down the way I insist it be done. Had to find out the hard way also, fortunately it only took a couple of them to figure it out. The strength in 11ga. square steel tube is in the walls, not the middle. A washer that doesn't bridge the 1.5" width completely will indeed concave the square tube when torqued down.
I paid for a bunch of so-called "fender washers" before finding out they were so thin it would take a stack of 4 of them to not cave in with the steel. Those had the correct bore, and the desired width, but are for some other purpose than mine. I was using 1/2" bolts, and learned to use a standard 1/2" washer on top of a stack of 2 standard 3/4" washers to achieve zero deformation of the tubes. You just need to center the oversized washers before final torque. Ended up using only a single 3/4" washer in most spots, but doubled up on others.
As stated above, karl states correctly that boring through tubes for a bolt weakens the tube, and welding on some tabs only strengthens it. For my purposes the bores through the tubes that were then strengthened by the washers did all that I needed, but the facts remain. Welded tabs are your best option.

 

[Denny]

Thanks Karl my point exactly. And thicker will not be subject to cracks as easily from metal fatigue.

 

[WillMatrix]

I must disagree, my 520# kart is built from 1.5" square 11 gauge steel, and is bulletproof, stiff as Biff.
Look at the parts of the backplate that actually connect to anything.............that's the 4 bolts that pin it up against the engine, and the built-in jackshaft. You can cut away any part of the backplate that wouldn't increase torque on those parts beyond what it would take to snap the potmetal backplate, people do it all the time for clearancing. Leave as many "ribs" as possible.
NOTE: A separate jackshaft mounted to the frame eliminates the need for any backplate at all.

Thank you so much. I also looked at some famous youtubers and they made big cuts on the back plate but just stood away from the gussets on the jackshaft area. I made the necessary cuts and I'm extremely happy. The only thing I'm dealing with is the massive torque that pops the bike up when I give it a little throttle

 

[madprofessor]

the massive torque that pops the bike up when I give it a little throttle

Had same problem with too much power. Adjustable wheelie bar fixes that....................

 

[WillMatrix]

Had same problem with too much power. Adjustable wheelie bar fixes that....................

That build looks sick. Where did you get those handle bars

 

[madprofessor]

Built it all myself. Handlebars are 1" square tube steel with 3/4" EMT conduit stabbed all the way to the bottom in the square stuff. Hand bent the EMT with a common manual electrician's conduit bender, but stuffed it with 1/2" EMT before I made the bends. Wish there was a video of my lightweight behind jumping up and down on that bender to form those 90's with all that EMT being forced to bend to my will.
Being double-walled like that made them bulletproof stiff, and the square/round transitions were literally filled up with scrap pieces of steel trimmings, and many many welding rods being melted into it all until pretty.
You might notice that there's also square steel forming the back end of the frame to expand the tubing to fit the 212 and the CVT, with no room left over. Same time-consuming transitions for the square/rounds. Took custom motor mounting to get it level for the oil. Wheelie bars have roller skates' trucks and wheels, can actually steer it because of the trucks when just comfortably laying back and cruising around with the sky in my eye and everybody applauding.
Ridiculous toy, 12+ hp., thought my homemade seat would be okay ay 17" long, scoot forward to hold the front end down on takeoff. Stupid. Thing would raise me up in the air like a floor jack in an auto shop. Never even got a proper test run from it, because it would go from putt-putt to Jesus Save Me! in 3 seconds flat. Sent a helmet, and knee and elbow pads along with it to the guy in Ohio that bought it, and my strong prayers for him to be okay and not die. He's probably still in the hospital.
EDIT: Did you notice my one-of-a-kind creation real functioning MONOshock springer front end? And the first-aid kit?
EDIT: Forgot to mention that I also sent the buyer a pair cutoff diving gloves to save his knuckles from road rash (in case he lived through the big dump).
EDIT: Anybody notice the custom shock absorbers I made for the wheelie bars? Whip it back, it doesn't bounce, just settles in smooth. Can ride around all day just leaning back on the rear wheel/wheelie bars, steering around cars, stopping without having to put it down, etc.

 

[WillMatrix]

Built it all myself. Handlebars are 1" square tube steel with 3/4" EMT conduit stabbed all the way to the bottom in the square stuff. Hand bent the EMT with a common manual electrician's conduit bender, but stuffed it with 1/2" EMT before I made the bends. Wish there was a video of my lightweight behind jumping up and down on that bender to form those 90's with all that EMT being forced to bend to my will.
Being double-walled like that made them bulletproof stiff, and the square/round transitions were literally filled up with scrap pieces of steel trimmings, and many many welding rods being melted into it all until pretty.
You might notice that there's also square steel forming the back end of the frame to expand the tubing to fit the 212 and the CVT, with no room left over. Same time-consuming transitions for the square/rounds. Took custom motor mounting to get it level for the oil. Wheelie bars have roller skates' trucks and wheels, can actually steer it because of the trucks when just comfortably laying back and cruising around with the sky in my eye and everybody applauding.
Ridiculous toy, 12+ hp., thought my homemade seat would be okay ay 17" long, scoot forward to hold the front end down on takeoff. Stupid. Thing would raise me up in the air like a floor jack in an auto shop. Never even got a proper test run from it, because it would go from putt-putt to Jesus Save Me! in 3 seconds flat. Sent a helmet, and knee and elbow pads along with it to the guy in Ohio that bought it, and my strong prayers for him to be okay and not die. He's probably still in the hospital.
EDIT: Did you notice my one-of-a-kind creation real functioning MONOshock springer front end? And the first-aid kit?

Pure genius!!!! I have been thinking of some suspension handle bars for my coleman and maybe even a swing arm. It's builds like this that makes me want to further my very small knowledge on fabrication

 

[madprofessor]

some suspension handle bars for my coleman

So you don't waste T&M on the wrong stuff.............The 2 springs I used for the monoshock front end were a little too soft for my taste, ordered from some minibikes parts supplier I can't remember as matching rear suspension springs. I've got built-in muscle-memory of running some really hard front suspension racing dirt bikes in the hills (think of big flights, high and hairy) of Tallahassee, FL. Those 2 springs together had to be cranked down a long way to get close to the stiffness I wanted, which reduces the available travel on that setup. Still had full travel to hitting the fixed/sprung forks together though. I used the 2' long piece of 5/8" threaded rod through the springs that you can see in the picture to get the stiffness set right before cutting it off.
I learned that the rockers' setup acted as a force multiplier that required stiffer springs, but no stronger open-type springs were available otherwise. Here's a thing I learned about springers: The longer the axle's center line is from the fixed forks' center pivot point, and ALSO, ALSO, ALSO, ALSO the longer the axle's center line is from the springer forks' pivot point, the softer the ride will be. That was a real surprise, surprised that I hadn't seen the geometry of it before finishing the design. To get a stiff suspension for hitting speed bumps at high speeds or high-jumping out of ditches, things that will change your axis of steering radius (very bad, maybe very squirrely, also happens in a "3rd wheel" powerslide of your inside foot down by the front axle) (think about doing an endo via jammed steering), just avoid the force multiplication of those multiple pivot points altogether. That geometry can compare to what would have been a common block and tackle for easily raising the heavy canvas sails on Blackbeard's pirate ship. (BTW: The "Queen Anne's Revenge" was sunk off the N.C. coast. No treasure. No Blackbeard.)