Mid- Engine Modified Sports

[Glen]

I was wondering as well, maybe put the bearings on first then bend.

[manta22]

Rex;

Glen is right, the bearings slip on over the tube and then the bends are made. I'll use split shaft collars as thrust bearings to keep the tube located laterally.

Regards, Neil  Tucson, AZ

[Rex Schimmer]

Nice build Neil, glad to see you are back at it.


Rex

[manta22]

In answer to a question about how the radiator is mounted in my black Mirage, I'll insert some pictures. I realized that I had never taken any pictures of the radiator and its support structure so I went to the shop and snapped a few. First is the general layout. Second is is how I added a few small square tubes for support. Third, to prevent fatigue cracks in the mounting flanges, I added some anti-vibration grommets to the mounting bolts.


This is a Howe aluminum radiator. I hope this explains how (no pun intended ) it's mounted.
 
Regards, Neil  Tucson, AZ

[manta22]

Somehow the other two pictures didn't get attached.

[manta22]

I've made a little progress on my black Mirage in the past few days. I measured very carefully from the outer chassis tubes and made a "chalk line" on the floor under the car, indicating its exact center line. Now I have reference points to re-position my rear suspension inner brackets.
 
I fabricated a couple of end fittings for my front anti-roll bar and have half finished the links and upright attachment brackets but I haven't received the anti-roll bar back from Wade, who is bending it for me. It is probably wise to mount the bar first and then finish the rest of that attachment.
 
Today I did get a pair of Tilton fluid reservoirs mounted. They are bolted to an aluminum bracket which mounts on the top forward bulkhead tube with Riv-Nut threaded inserts. I haven't pushed the top & bottom of the reservoirs together yet (they seal with an O-ring) so that I can cut off the bottom hose barb and then thread it for a nylon compression fitting. The connection from the reservoirs are 1/4" Nylo-Seal tubing. One MC is for the brake system and the other is for the hydraulic cylinder that operates the clutch.

Regards, Neil  Tucson, AZ

[dw230]

Neil,

I grew up with "chalk on the floor" designs. May I suggest some method of securing the centerline and chassis to the floor? Arizona may get an earthquake and then the fixture goes all to heck. Hate to see that car crap walking down the track.

DW

[manta22]

 Dan;

Rest assured that the centerline (orange flourescent nylon cord) is securely taped down to the floor. Now, if AZ has an earthquake ....
Actually, I marked the centerline on both ends of the chassis, too, so putting it back would only require a plumb bob.

BTW, when I was a kid, we lived in the outskirts of Tokyo right after WW II so I'm certainly familiar with earthquakes. We had them every few weeks-- small ones, fortunately.

Regards, Neil  Tucson, AZ

[manta22]

Little construction details take time but are either necessary or sometimes just worth doing. My Tilton brake fluid reservoirs are made with hose barb fittings but I wanted to run nylon lines with compression fittings so, there being no other choice, I sawed the hose barb off, drilled the hole larger and tapped it 7/16-20 UNF, which is the thread used on a 1/4" nylon fitting. The plastic is not very thick on the reservoir bottom, so I used a thin nut on the inside to make the fitting connection stronger. The fittings I used are "262-N 04", that I bought from Aircraft Spruce; they are intended to mate two 1/4" tubes but I simply removed the nut from one end and threaded that end into the reservoir with the 7/16-20 nut inside.

To insure a leak-tight connection, I applied a bit of Hylomar sealant (the blue stuff) to the threads before screwing it together. Now it looks like this: (see photo)
To connect the tubing, it is simply pushed into the end and the compression nut tightened snugly. It's nylon so the nut needs to be tight but not so tight that the threads are stripped.
Yes, I cleaned up the excess Hylomar. 

Regards, Neil   Tucson AZ

[Milwaukee Midget]

It looks more like what one would see in a hospital than in a race car. 

Thanks for getting back on track and posting on this one. 

[manta22]

Wade finished bending my front anti-roll bar, so I was able to do a trial fit and then fabricate the necessary lower bracket to connect it to the upright. Originally I had intended to use a pinch tube bracket to connect the bar itself but, after mounting the bar, it looked like there was very little space between the coil-over spring and the upright so I just drilled a series of 1/4" holes in the bar so the very short link can be adjusted on the bar. The bottom bracket was fabricated out of some aluminum angle extrusion that I already had and it is mounted on the existing lower ball joint thread. I also drilled a series of holes in it for the link adjustment.

The link was made of aluminum thick-wall tubing that Coleman Racing sells; it's ID is the correct size to run a 3/8-24 tap through-- neat stuff. The rod ends are some nice surplus ones made by Astro back when they specialized in aerospace bearings. The ball has a 1/4" hole and the shank is 3/8-24 UNF. Both ends of the link are tapped with a right-hand thread since those were the rod ends that I had so the link has to be undone on one end to be adjusted. That doesn't seem to be much of a problem since they will be adjusted only once.

I was apprehensive about the anti-roll bar clearance as the front wheels were turned left & right but I guess I measured things right-- there is no interference.


Now I need to quit looking at these pictures and get back to work.

Regards, Neil  Tucson, AZ

[Glen]

Neil
Are the Heim joints alum, or steel. Alum is not allowed. Also will need washers so the bearing can't come out of the joint. You probably already know this. The build is looking great.

[manta22]

Thanks, Glen-- yes, I know about the washers; this is just a trial fit.

No, these are 17-4PH stainless steel aerospace rod ends. I'd never use aluminum rod ends in a structural application-- to prone to fatigue failure.

Regards, Neil  Tucson, AZ

[manta22]

Maybe it wasn't my best idea  -- the lower bracket does rotate with the upright. The bar stiffness calculated by my software allows an adjustment fairly close to the ball joint pivot point so there is not much movement other than rotation which the link can handle. The idea was that for LSR I only needed enough steering angle to stay within an 80 ft wide lane so it seemed like a good idea.
 
I thought about this further-- maybe it wasn't such a good idea after all. A severely limited steering would make getting the car on & off the trailer a nightmare, as well as getting around the pits and recovering a spin on the track. Maybe the tech inspectors wouldn't even accept it.
 
I am going to re-do the lower attachment point so that it attaches to the lower A-arm. It looks like I have just enough room to clear the coil-over so I'll make a cardboard template to try it and then fabricate one in steel and weld it on.

Later....I think I've taken the front suspension off & on about 5 times in the last three days now but it finally looks OK. The anti-roll bar link clearance is tight but it does clear everything, even when the wheels are rotated lock-to-lock and up & down. I had to grind a bit off the lower suspension upright but only a little. I'll need to add a large washer to the top rod end bearing; this is required so that a separation of the ball from the housing doesn't let things get completely haywire.

Regards, Neil  Tucson, AZ

[Milwaukee Midget]

A severely limited steering would make getting the car on & off the trailer a nightmare . . .

That would be a resounding yes.  After going with 15" wheels, 22" drag fronts, and lowering the front end, I had to restrict the stops on the Midget to prevent rubbing on the inside of the fenders.  Even with an 80" wheelbase, my Dodge Magnum currently has a tighter turning radius than the Midget.

It's not a nightmare, but it does require Tylenol. 

Chris