Mid- Engine Modified Sports

[manta22]

JH;

Street..? Probably not-- I'm committed; the roll cage kind of precludes that anyway.

These aluminum covers are easier for me to make than to fool around with fiberglass-- I'm just not very good at 'glassing. The aluminum is only 0.040", has tapered edges and the rivets are flush so the airflow disturbance should be minimal. If this were a fast streamliner I'd do this differently.

Regards, Neil  Tucson, AZ

[manta22]

I finished the right- hand headlight pop- up cover this afternoon and riveted it on. It looks a bit strange in the zinc chromate yellowish- green color. I'll paint them black later.
The fiberglass body under the nose was missing an angle piece to clamp it up to the tube structure around the nose and it was sagging down (unacceptable!) so I rummaged around in my surplus collection and found a 2024-T3 "Z" section extrusion and used that to fix this problem. This is visible in the lower edge of the nose air intake-- the black bar with a row of screw heads visible.

Regards, Neil  Tucson, AZ

[manta22]

Progress has slowed to a crawl but there are a few new things evident on my BGMS build. The top tubes tying the front & rear roll cage hoops together are in place but not yet tack welded. There will be a titanium sheet across the top of these tubes to stiffen & strengthen the structure. I hope to get back to work in earnest next week.

Regards, Neil  Tucson, AZ

[Jonny Hotnuts]

You gonna run a radiator and not a tank? I ask because it looks like I can see one under the hood exit.
A rad wouldnt be my first choice.

ALSO~ How can you stand to work in a shop with so much dirt on the floor! 
(I could only wish mine looked like that)

~JH

[manta22]

JH;

Yes, that's a Howe aluminum radiator up front. I might like to run my car in a few events like "Track Days" so a water tank was out.

I chose that floor color because I was tired of losing small parts that I dropped on a gray floor. 

Regards, Neil  Tucson, AZ

[hotschue]

Hello Neil,  Good to see you working on the project, it's looking good...Friend of yours stopped by the shop last week, John Sable, to inspect my nose cone plug.  He said, "making the mold there's nothing to it", easy for him to say...we'll see.  John will be making the trip to B'ville with us in '10.

[generatorshovel]

Want to swap workshops ?

Tiny

[manta22]

Thanks for the offer, Tiny-- I think I'll keep my workshop.

Regards, Neil  Tucson, Az

[manta22]

Hello Neil,  Good to see you working on the project, it's looking good...Friend of yours stopped by the shop last week, John Sable, to inspect my nose cone plug.  He said, "making the mold there's nothing to it", easy for him to say...we'll see.  John will be making the trip to B'ville with us in '10.

I haven't seen John in 40 years! He ran off a copy of his Corvair powered mid engine sports racer from his molds-- I still have that fiberglass body but its in ratty condition. Please tell John that I'm looking forward to seeing him again. I've attached a photo of his car at Summit Point in 1969; John is holding his daughter on the right and I'm adjusting the wing.

Regards, Neil  Tucson, AZ

[manta22]

More progress yesterday-- I cut a sheet of 6Al- 4V titanium to fit across the top of my roll cage; a 0.050"sheet that is a shear panel to stiffen & strengthen the structure and keep my helmet off the salt if I roll the Mirage.  I used a plasma cutter to cut the titanium and then smoothed the edges with an angle grinder. Drilling all those holes was NO fun. I'll rivet it on after the chassis is finish welded and painted. By using C-clamps to hold the sheet to the tube and progressively drilling my hole pattern fron the center to the edges, the titanium sheet was formed to the top of the cage. Cleco spring fasteners held things in alignment but where the curvature was highest it required cylindrical Cleco fasteners. This type has very high pull- down capability. When the chassis is finish welded and painted this sheet will be riveted on with Monel CherryMax rivets. These have an A286 stem and are rated at slightly over 1600 lbs shear strength each!

Regards, Neil  Tucson, AZ

[Glen]

Neil, looking good. As always neat work takes longer but always worth it in the long run.
 

[Stainless1]

Neil, are you sure you wanted to drill all those holes in your roll structure?  will that make your cage weaker.    Please be sure all of those holes are well sealed or your cage will rust from the inside.  Just a little concerned.

[Rex Schimmer]

Neil,
I probably need to insert my 2 cents worth on the rivetting the Ti panel to the roll cage structure, I think I agree with Stainless that drilling that many holes in the roll bar structure may not be the best idea, you may want to check with the SCTA to make sure it is acceptable.

Rex

[manta22]

Rex & Stainless1;

I looked at what those holes would do to the tube structure and concluded that riveting the shear plate to the tubing would make little if any difference in tubing strength or yield. The roll cage is 1 3/4" dia x 0.120" wall thickness mild steel tubing and the Monel rivets are only 0.170" in diameter. These CherryMax rivets are actually stronger than the steel tubing and pulling the rivets expands the rivet body which carries the stress loads through the steel. An unfilled hole is weaker than one with an expanded high strength rivet.
I considered welding a sheet of cold- rolled steel across the top of the cage but it added weight where I didn't want it-- raising the CG of the car. That's something I'm trying to avoid.
Regards, Neil  Tucson, AZ

[manta22]

Here is a photo of a trial fit of my firewall. It is 0.090" titanium and will be bolted in place to small tabs that are welded to the roll cage hoop and bracing tubes. The small gaps in the firewall will be sealed with 3M fire putty sealant.

The firewall will give good protection from a fire or engine blow- up. For heat insulation, I'll add a layer of woven ceramic fiber cloth.

Regards, Neil  Tucson, AZ