tube frame/cage mini sprint build

  I always heard if you  can  remember the 60's you didn't participate to the max.

The first crossmember for the upper section is tacked in place.  Seems I was one step too quick in sticking in the rear engine cradle uprights.  Otherwise I could have built the entire section right on top of the bottom.

Unless you lived in the prairies. The 60's didn't hit the prairies until the 70's.

Ya.  I'm a mid amer boy & the 70's here were pretty rowdy.  But, being a serious gearhead, I was always more involved in my current rig than the hard party.  Looking back, think I dodged a bullet by not participating excessively.

Give your kids a car hobby, and they won't have money for a drug problem.

I may have missed it - are you a soft-spring/big-bar person, or are you going all spring?

Ya, that's where virtually all of my spare money went.

I like the idea of using the bars for managing body roll.  However, with most of the weight between the wheels, should be not too big a problem.  Want it to corner like a go kart on rails!

In my mind, there seems to be some advantage in being able to soften the springs, if needed, for best suspension compliance with track irregularities...& still have it cornering flat.

Shocks & coil overs...Still thinking about that.  Probably something for an ATV type vehicle.  My best guess, at this point, on total weight when finished is 600 - 700 lbs.

I cut some blocks to hold the upper section at the proper height for fitting.

The stems sticking off the back of the eng cradle are in the way.  Front of crossmember needs to go forward to the edge of the square.

Try to be careful when trimming, looks like the stem might be at the proper height to tie into the crossmember.

So you are keeping the section of the motorcycle frame for the engine? I'm slightly surprised that you aren't making your own cradle/mounts.

Thought about it.  Decided that when it's all said & done this will fit in as well as anything I'd scratch together.  Saved some time on the build as well.

The upper rails for this section came together very well.  I've got square between top & bottom tubes at all points.

Cut the blanks for the uprights 4 corners & fitting them for length in the fixture I set up previously.  By fitting them all to the same standard on the bench, I'm assured of consistent height dimensions on the build.  

As these corners are T joints, I've got to fit them around that tube as well.

One down, three to go.  The large magnetic jigs have a 50 lb hold & are killer strong.

Not quite stack o dimes pretty yet.  But, they're hot & deep & strong.  That's the main thing!

Straight edge shows me that the uprights are in line with the cross member.  These are the mounting points for the suspension & it's essential that tolerances are as tight to the design as possible.

Starting to look like something, now.  

Got ma guard dog, Lou, hangin with me today.

I don't recommend fully welding anything until it's fully tacked together.

The fully tacked assembly helps hold it together and prevent warping, and it's a whole lot easier to make changes if it's only just tacked.

Looks good though!

Thanks.  Normally I don't weld solid at this point.  However, I did want the crossmember tubes welded solid before covering them with the vertical tubes.  Annnd, since I was welding annnd....well, you know...

Jigging up to build the front.

Front top section fitted & tacked.

Cutting ball joint plates for front control arms.

Ognib said:

Junkyard parts for the final drive.

Pull the center section out of the housing & fab a "can" to hold it...replace the ring gear with the chain drive sprocket.

 

Pressed the wheel bearing hubs out of the stock cast pieces & discarded them.  Axle shafts will have to be shortened.

Template for hub backing plate.

What did you pull those from? I have an itch to make an off-road buggy/go kart and that looks like a nice lightweight setup. 

EDIT: Re-reading shows you already specified Subaru, but what subaru?

05 Legacy.

In reply to Ognib :

Good to know, thanks! I'm excited to see how this comes together!

AWSX1686 said:

In reply to Ognib :

I'm excited to see how this comes together!

Thanks, me too!  

I like engines.  Engine work is, to me, one of the more enjoyable parts of building stuff like this.  A lot of guys spend obscene amounts of money to go racing.  In the early days it was mostly drag racing.  My approach was & is to take what ever rig I currently had & study how to make it better.  More interested  in racing against myself than against the guy in the other lane.  

This approach to the game was much more satisfying to me & saved me a lot of money over always buying the latest trick speed part.

My first "nice" engine was a lil 283 chev that we bored .125 to make 301 ci.  Duntov fuely cam, 10:1 & some blueprinting clearances & check the balance on everything. Then basic stuff like hand porting the bowls behing the valves & port matching to the gasket sets on the intake & exhaust, plus a basic set of headers built from salvaged various bends off of junk yard exhaust tubing & welded with ox/accet.  In a 56 chev 2 dr, wasn't at all fast by todays standards but held it's own perty good for the 60's era, small town, lo buck street strip/scene.  Hot rod & car craft magazines were my bibles.

The engine going in this project is 650 cc & is early 80's.  Tag off the donor bike rates it at 84 hp.  No computer, just carbs & timing to piddle with.  It's Calif compliant on smog, so I figure that with some jetting & timing tweaks, it should have a bit more in it than that.  9k redline.

It's my understanding that the 750's were built on the same lower crankcase as this motor.  Get the build finished & running the way it is & then do a displacement increase with a bigger set of barrels etc as a winter project.  Just fer grins!

This guy has a series up on a top end build on a kz 650.  Very thorough & articulate.

An "update", to keep the thread from going inactive.

Wife has had some health problems past 6 mo or so & I've been busy paying off med co-pays...so no buggy buildin right now.

Plus, job i've been working past 9 yrs is shutting down at end of yr...busy lookin for a suitable replacement.

Fun-n-games 

In reply to Ognib :

Sorry to hear about your wife's health issues and the job. I hope that both situations improve for you quickly.