Misc. Mechanical & Metal Fabrication

[Loren]

That book, "The Nature of Boats", will be coming here via Amazon. Thanks for recommendation.

Time to do some yard-clearing around here. First is an '86 Corvette I bought cheap after it had been T-boned in a wreck and de-engined. All I want is the front/rear suspension which come out a little easier if you turn it upside-down. Couldn't figure out how to open the rear hatch, whatever lever or key thing they must have had was missing. Since they are pretty common I finally just broke it with an iron bar. It took three pretty-good whacks to do it, of-course I was shop-vac'ing glass pieces outta the car and everything else nearby for a while afterward. Having removed the hatch by that method, it then becomes apparent that you can just pull on a little cable that comes out of the latch mechanism from the inside, and "click".



Next is a '94 Trans-Am. This sat in a storage yard without the registration being paid until, together with other needed repairs, the amount of fees, interest and penalties was too high to make it worth putting on the road again. California will do that to you, if you skip paying charges they will send letters to your home demanding the money or threatening to have it taken out of your check, just like the tax man, and it doesn't matter if you're actually using the car or not. Severe. Anyhow, that being the situation I got it cheap for parts. What I want is the LT1 motor, six-speed, and all the stuff like cooling, electronics, hvac and the rest. All other parts have sat on Craigslist with exactly zero interest, so plastic doors, fenders and interior are all headed for a dumpster if I can't find a recycler, while the metal can go to the local scrap. There are only two of those bling wheels anyhow, another is damaged and the fourth is missing altogether.

Note chicken wandering through picture, we have a couple loose in the yard to keep the insects down.




Yet another project starts in the garage, not what I need right now but this is where the 'Vette suspension is going and I wanted at-least the rear portion nailed down while I had the body around to take measurements off of. Shown are rocker rails and rear mains, .104" steel formed on the pressbrake and tig-welded. This will be a highly, highly modified early-nineties Toyota Supra, there may be very little Supra left when done. "Sports" car, not a drag car. Maybe some of my other crap projects around here will disappear in favor of that one.


A recent remark, which I sorta brushed off at the time, remains sticking with me. That is the process by which people change their minds, I suppose.

You need to get things of finer vintage, that's just box wine.

Finally, the Wife likes it when I sit down to make something like this for her periodically. Carved-out of brass, maybe some day I will take this and the bunch of others made over time to be gold-plated...in this case I think I need to take it back and do a little more work on the bumpy parts first, the photo really shows them. Seems my eyes are not what they used to be and as you can imagine, holding onto this tiny stuff while cutting and filing away is kind-of a trick.

[DanStokes]

That book, "The Nature of Boats", will be coming here via Amazon. Thanks for recommendation.

Time to do some yard-clearing around here. First is an '86 Corvette I bought cheap after it had been T-boned in a wreck and de-engined. All I want is the front/rear suspension which come out a little easier if you turn it upside-down. Couldn't figure out how to open the rear hatch, whatever lever or key thing they must have had was missing. Since they are pretty common I finally just broke it with an iron bar. It took three pretty-good whacks to do it, of-course I was shop-vac'ing glass pieces outta the car and everything else nearby for a while afterward. Having removed the hatch by that method, it then becomes apparent that you can just pull on a little cable that comes out of the latch mechanism from the inside, and "click". [ATTACH=CONFIG]n1139433[/ATTACH]



Next is a '94 Trans-Am. This sat in a storage yard without the registration being paid until, together with other needed repairs, the amount of fees, interest and penalties was too high to make it worth putting on the road again. California will do that to you, if you skip paying charges they will send letters to your home demanding the money or threatening to have it taken out of your check, just like the tax man, and it doesn't matter if you're actually using the car or not. Severe. Anyhow, that being the situation I got it cheap for parts. What I want is the LT1 motor, six-speed, and all the stuff like cooling, electronics, hvac and the rest. All other parts have sat on Craigslist with exactly zero interest, so plastic doors, fenders and interior are all headed for a dumpster if I can't find a recycler, while the metal can go to the local scrap. There are only two of those bling wheels anyhow, another is damaged and the fourth is missing altogether.

Note chicken wandering through picture, we have a couple loose in the yard to keep the insects down.
[ATTACH=CONFIG]n1139435[/ATTACH]



Yet another project starts in the garage, not what I need right now but this is where the 'Vette suspension is going and I wanted at-least the rear portion nailed down while I had the body around to take measurements off of. Shown are rocker rails and rear mains, .104" steel formed on the pressbrake and tig-welded. This will be a highly, highly modified early-nineties Toyota Supra, there may be very little Supra left when done. "Sports" car, not a drag car. Maybe some of my other crap projects around here will disappear in favor of that one.
[ATTACH=CONFIG]n1139437[/ATTACH]

A recent remark, which I sorta brushed off at the time, remains sticking with me. That is the process by which people change their minds, I suppose.


Finally, the Wife likes it when I sit down to make something like this for her periodically. Carved-out of brass, maybe some day I will take this and the bunch of others made over time to be gold-plated...in this case I think I need to take it back and do a little more work on the bumpy parts first, the photo really shows them. Seems my eyes are not what they used to be and as you can imagine, holding onto this tiny stuff while cutting and filing away is kind-of a trick.
[ATTACH=CONFIG]n1139436[/ATTACH]

As always, interesting stuff. And I think the charm looks just fine!

Dan

[SuperBuickGuy]

dang, and I was just sitting here....

[Loren]

Disassy on the Trans Am continues, now-and-then. I had saved the wiring harness from the Corvette for no particular reason except to have in stock 'cause I never know when I might need a wire of some particular color or an odd relay , it took a few hours to remove in one piece (or should I say, tangled clump)...choosing to do the same here because I want to keep it with the motor, the giant wad of wires is probably around twice the amount of what was in the 'Vette and is taking well over twice the time to label and drag out. From an '86 Corvette to a '94 Firebird, it got that much more complex. I have hours into this and am only half done...photo shows the major portion of the chassis harness pulled through the firewall onto the engine but there is more, and I haven't even started on the engine compartment yet.





I am down to giving away T/A parts to anyone who wants to come get them, still no takers. As cool as they were when they were new, these now-20+ year old "pony" cars (they'd make for a pretty fat pony) appear to have little collector interest. The sheer amount of plastic in this car has been filling up my generously-sized city-issue trash barrel for weeks. I hate throwing out perfectly good stuff but then, junkyards and landfills are full of what I consider usable stuff anyway.


Reading through another member's thread--- http://www.bangshift.com/forum/forum...ed-off-grandma --- I had come across this:

ok going a different route with the front brakes so if any one wants b-body spindles and 12" 1le rotors let me know

Long ago (the nineties) I had used the B-body spindle/1LE brake upgrade on my '70 El Camino (along w/ Cad Seville rr discs), liked it a lot and wanted the same deal on a '78 Elky I have around as a one-of-these-days project. For a few bucks Thomas was happy to send his unused parts along over here in a big heavy (85 lb) box but as you might imagine, shipping costs from Michigan to San Diego were a killer. Still, I am pleased enough to have these here now and not be something on my mind to go hunting for.





For those unfamiliar, 1LE was an option on third-gen Camaros that used larger rotors from the Caprice that had the smaller-car 4 3/4" bolt pattern and the hubs machined down so the wheels would fit (Caprices with the 12" brake option had 5" patterns and larger center holes). These rotors which came from the Chevy dealer parts counter when I last bought them but are now usually China-sourced (oh well) conveniently fit straight on the Caprice spindles which are in-turn a some-modifications-required fit on the El Caminos (and other A/G's of course) and can be used to improve suspension geometry with their longer ball-joint-to-ball-joint dimension. The downsides are weight and slightly increased bump steer but on the street it's no trade-off, the braking improvement is huge and welcome.

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Rain, rain, and more coming to San Diego and hopefully the end of our years of drought around here. No problem (mostly) for me, about a week ago I finally got this metal barn I built to where I could get the cars into it that I wanted, a couple of these have been out in the raw weather for years. I started this deal five years ago by purchasing an already-standing structure out of Craigslist (it was only 2-3 miles away), disassembling, hauling, re-configuring and enlarging it and fastening it to a pad made of hand-stacked concrete chunks and road base. A shoulda-been-simple task that has taken forever, but there are extra features such as shelving/storage, security etc., and of-course a two-post lift bolted to a substantial reinforced concrete footing that the mentioned '70 El Camino can store on with the Camaro under it. (Next to that the '72 Corvette, Challenger, Impala.) All this is in the far corner of the back yard, behind two gates and whatever is parked in front of them, I still want to put privacy strips on the chain-link to keep the sun out but as this entire thing is supposed to be fire resistant I need to make something out of metal, not just plastic ones from the hardware store. So I'm not done completely yet.





Standing inside of this in heavy rain is a noisy experience! Kinda fun, actually.

Time for one more little project, jigging up these frame rails from a couple weeks ago for welding, then fitting in the Corvette rear and mocking up seating and hvac stuff for ongoing thought and measuring.






Total vehicle height will be 43-44", kinda on the low side. Later on I'll consider D44 and bigger brake upgrades here but I've got lots and lots, and lots, of fabrication work to do between now and then and this makes a fine mockup. Something to do on weekends when it's raining (did I mention the rain?) outside...thank the Heavens for rain, finally! (Just don't flood us out now...)

[Loren]

When I started this project thread I was inviting anyone to add in, mostly because the Project Forum was pretty slow at the time and I hoped it'd be encouraging to people who might not otherwise post...but these days I'm having to go four pages back to pick up this thread from only a month ago. A pleasure to see, I do like looking through people's builds.

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Most of my time on my latest is just mocking-up, staring, designing, re-mocking up, revising whatever design,then staring some more. 'Way back when I did the Challenger I didn't much mind building some part without first having a developed idea, then scrapping it out if it didn't work out and making another...this time I am preferring to avoid that but it's making hard progress come a little slow.

I did go by the metal supply and buy a handful of 3/16" sheared plates, bend a couple up for the shape the rr diff support crossmember ("batwing") brackets required then stack-and-tack them up to cut at once.








These go under the frame rails and serve as both aforementioned mounts and a place outboard to put bump stops. Stock 'Vette bump stops are fine but I'm moving the sway bar to a place they won't work...these new ones will nail where the support rod down to the leaf spring is bushed if I add some kind of additional hardware there, I will worry about details later. For now the first thing I see is that these go out too far and may hit the inside of the tire; no problem I'll just plan on trimming and completing the bump stop after actual brakes/wheels/tires are on. When will that be? No time soon, I like to do the hard parts like fab work first, then wait to spend money on the other stuff until really needed.








That sway bar end will be further away from the bracket once the rest of the "real" mounting bracketry is made.

The '94 LT1 engine from the Trans Am is there, but I don't want to use an LT1...however, since size and controls are similar enough to the newer stuff and the transmission is the same 6-speed, this will do for now as a mock up. I can see why they used ZF transmissions on the nineties Corvettes, the Borg-Warner/Tremec has some size issues and does not accommodate the rigid mount to the diff arm, but I can work around that here. Exhaust, especially if I wind up having to run dual converters such as come with the GM smog-legal E-Rod packages, is a problem and the whole front frame and suspension is having to package around keeping converters in front of the firewall. Beyond that there will only be room for one single exhaust...since the Firebird at 275hp was given by Mama GM a 2 3/4 single pipe, I think a single 4.0" should handle 430-600hp and I will stick it on the passenger side where people's feet don't have to move around so much.








I am giving up on the idea of using the 'Vette transverse front leaf spring because of packaging where I need the rearmost lower a-arm bushings to be further forward nearly in line with the axle centerline for exhaust clearance, putting them in the same place as that spring. A further problem for the fiberglass leaf spring is lack of adjustability...you need to really hit it right with one of those as far as rate and shape goes 'cause there's nothing like a screw to turn for ride height such as there is at the rear if you get it wrong. The 4th-gen F-body spring/shock unit looks like a winner here, and the high mounting of the springs means a secondary structure from the cowl area forward can be used to bolster the lower main frame and provide mounting for a cross brace in front of/above the engine and further tie the two sides together beyond the regular crossmembers. Lower a-arms will need to be fabricated now, with the forward bushings moved to the front quite a bit and of-course the spring-shock mounting changed.

Why not buy aftermarket coil-overs at this point? Simple answer, I don't have to. Those Camaro/Firebird parts will do the job and fit the package, and then there are still aftermarket parts for that application later if necessary.

Anytime you come up with some major particular idea for something like structure or suspension, part of the vetting (irony noted) process is to look around and see if anybody else successful is doing a similar thing already. If no one is, you are either really smart, or really dumb. In this case, British Aston-Martin is there for me, with virtually the same layout. Good, then we'll go forward.

[SuperBuickGuy]

I like the idea of tying the differential to the transmission.... I really need to dig out the guldstrand pieces - I have extras and they might save you a bit of fab and time... pictures tonight.

[SuperBuickGuy]

So the promised pictures
I have this stacked together incorrectly, but you'll get the idea


Greenwood's system is basically the C4 set up, Guldstrand is a bit more complex but in a sense is better control.

[Loren]

Great pic. That looks like a pretty trick update to the C2/3 stuff...thanks for providing links on your thread to the VetteMod forum for the back story. I had searched around there earlier when you first mentioned the downloadable files but didn't find what I was looking for then. Now after reading ten pages or so they're going to make me register to see any more but I get it. Pretty cool to have a free dxf and bring to a laser cutter with the material of your choice. I gather that the arc this takes the axle shafts through is close enough to original that you can just leave out the factory retention and let it slide, without having to necessarily go to the driveshaft shop for new axles to do it.

Happily, starting from a clean sheet on the frame and body for this, I don't have any packaging issues such what these are needed to work within and can stick with the aluminum C4 parts including carriers as-they-are. My issues and need for special parts at this point are all coming from the other end of the car.

This might make a nice deal for the '72 though, when I manage to get around to it. I've never been quite able to look over ol' Zora's original deal on that without a little bit of WTF element going on (of course the design was from the early sixties for six-inch-wide bias tires), this would solve a couple issues for sure.

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A couple remarks about tying the diff to the transmission, on the Corvette C4 it's a rigid tie made to eliminate the need for a transmission crossmember which that steel/fiberglass sorta-unibody has no structure for. It makes a bridge straight across from the motor mounts to the bat wing mounts. As you would guess, that does mean all stress through there thus goes through the transmission case and it needs to be made for it which the ZF used in those apparently was, I wouldn't try that with just any transmission. The connection here will be jointed similar to an H-body Monza or 3rd/4th gen Camaro and won't stress the trans any, but needs the conventional frame crossmember support which I happen to have room for here and can supplant with trans tunnel structure.

[SuperBuickGuy]

that is correct - the axle sliding. usually people cut the axle at where the keeper slides on so it can move inboard (otherwise the cross shaft will stop that). It does eat seals, though, because GM never considered we'd do that to them. The other way is people put slip joints in each half shaft.

f you want the files, I'll post them up a bit later. A warning, it doesn't have all the pieces - that inner bit for the axle isn't on the files (although, cutting a circle in the outside one isn't terribly difficult). Also, I may have more cut out out of the correct thickness material (and made of stainless) - let me know if you're interested in some as well.... they're not terribly expensive to have cut out - especially since it's already on their system.

you should join, though, some pretty well-known Corvette racers make that place their home - just don't ever suggest a stock build.... trust me on this.


so my question to you.... why don't they cross-brace the frame (the square under the passenger compartment? For my build, I really do think I'm going to pull the body off the frame to do the work and weld up the frame. Also, have you seen the article GM put out for racers about how to brace and strengthen the frame (it's a Chevrolet Performance article)? If you haven't, I'll dig mine up again and scan it.

[Loren]

It's probably important to make sure the sealed area on the shafts doesn't have a groove worn into it that then slides back-and-forth against the seal. I once modified a rear-end cover to gather some more of the oil splash it got off the ring gear and feed it down to the axle seal area on a 12-bolt, meaning down the axle tubes, and it worked pretty well.

I should think you'd absolutely want to get that body out of the way to do serious suspension mods. You just have to lift it really careful, keeping in mind the heavy, long front clip is glued to the cowl and you don't want it to just hang or things might start cracking (even support, however you do it, is important). After that it can sit on some kind of dolly with wood beams or whatever making the distance across to the mounts, and roll the whole thing out of the shop.

A trans crossmember, with the long span it makes between the rails, is a design problem on any very-low-slung high-perf car with a perimiter frame due to it's weight, having to tangle around the exhaust, the floor clearance issue and after all that it contributes essentially nothing to torsional stiffness because of it's thin cross section and lack of rigid mounting if it's going to be removable. I always thought it was very trick that the C4 designers were able to eliminate it. However it's also possible that some of the C4's rattles and plastic-squeaking are attributable to that choice as well as some of the other unique fiberglass/stamped-steel-interfaced architecture and at the end of the day, who wants to drive a car that squeaks? Better to go ahead and add a few pounds, sit an inch-or-two higher.

My '72 had all the GM-recommended bracing when I got it, performed by some guy who could neither weld or even see straight. He did such a crappy job, we cut them all out. Some may go back in (properly) 'cause there's places it looks like it could use it, such as around the lower a-arm mounts and other areas. I gotta say though, looking at old 'Vette frames often enough, rust seems to kill them more than fatigue/stress failure does but then these don't usually come from raced cars either.

[STINEY]

Do they make a SpeedySleeve that fits that area? SpeedySleeves have went up in price, but are still a neat fix to a worn shaft seal surface.

Might be worth it on a conversion like this?

[SuperBuickGuy]

I have a pretty clever body caddy, that is built for Corvettes, I bought at a swap meet few years ago that properly supports everything. I need the body off to fully weld the frame - not looking forward to doing this .... ah well, it's better then TV.

I'm not sure I'd blame the post-production welder - my 75 had some of the worst welds, that I've ever seen, that were installed by GM.

nice thing about living where I do - rust rarely kills them. The only rusty frames/windshield frames that I've seen came from the east.

[Deaf Bob]

I'll second the "worst welds from factory" statement!
GM and Ford all years. Even Mopars.
There are places I hit with a stiff wire wheel that were just flux..
We always used to completely reweld frames, now many places ban it except firewall or a-arms forward..

[Loren]

The Firebird: Out...mostly. The scrap yard wouldn't take it as a "restorable" vehicle, they want "parts" only and had me cut it in two...after bringing it back home and doing that it occurred to me I might want to save the rr brakes so I only brought them back the front half for now. SpiderGearsMan used to say what a pain these years of F-body were to work on, such as something like six or nine hours of work to do a heater core; I can attest to how many layers of parts and plastic have to be removed to get to such a simple thing. In, out and over, these cars were made for putting together at the factory and not for guys in their yards to take apart.




Then back to metal fab and the chassis project shown earlier. After some thought I've chosen to not use the C4 huge aluminum bridge between the trans and diff housings although it could've been re-purposed as a torque arm. A steel "ladder bar" will do instead and accomplish diff mounting more like the C3 Corvettes, requiring a frame component to attach to as well as a trans mount cross member now, but more workable for my frame layout. First I rummage around through my box of various rubber suspension bushings that didn't get used on other projects and come up with an A-body rr pivot that happens to be about the same size and stiffness as I believe is needed, then measure it out and cut a strip of 11ga steel to make a press-fit socket for it. Figuring width of such a part is easy, but how to know how long to cut the strip so it rolls around to the right size? Take the diameter of the bushing, plus the material thickness being used for the socket x about .45 to get to a neutral line between where the material is stretching and shrinking (and that number needs to be added in twice because it's a radius figure and we need a diameter), and x good 'ol pi in honor of today's date (3.14). This strip gets laid over a steel bar and hit multiple times with a v-die to bring it around. Bending even radii (minimizing runout) on a brake is a little trickier than it looks but patience does it. Of-course you could just use a hammer too, no reason to let not having a press stop you.




Measure, measure, cut, bend, drill, measure, weld. It took all day to make one simple smallish part but that's how it goes. The little stop bolt in the front will make sure that bushing, once pressed in, never goes anywhere. In this photo, the part is upside-down. Add nine pounds now, the weight of the whole much-larger 'Vette aluminum backbone brace was eight.




View from above the diff housing forward, ladder bar installed. The purpose for it having one rectangle member mounted vertical and one horizontal is to work around the driveshaft.




More press brake. For bracing to help support the new ladder bar mount and to have the passenger compartment be as rigid a "tub" as possible in what may possibly be a removable-roof car, I need the transmission tunnel to be a major part of structure and not allowed to crumple easily and these 12 gauge (.104") strips running along the top corners, reinforcing the thinner floor and trans tunnel material, should help. Again, it takes multiple hits and adjustments to get a smooth radius bend when using dies with a smaller radius than you want. Why not just use a bigger-radius die? I don't happen to have one. I once worked with a guy who was a master at this sort-of thing, he used to make aircraft wing skins this way so it's good enough for me. Bam bam bam, there have probably been a dozen hits into this here with a dozen more to go.



Below: The bracing strips in place, welded at the rear to the ladder-bar mount which will also serve as the upper-rear of the trans tunnel, and up front to a truss structure to put crash and general loads out into the cowl ends (still to be made). The whole thing, cowl-to-crossmember but not including the ladder bar, weighs 27 lbs. as more poundage gets added on but I believe it's necessary here. It's my butt this thing is going to be wrapped around!




Below pic; from the side. The front truss occupies the area from a comfortable distance off the driver's leg at the rear, the pedal travel limit at the front, the steering column and hvac above, and the transmission below. The front of the truss (tensile loaded in crash) is 1x1x.12-wall square, the angled rear compression member is 1 1/4" round squished into 1" obround for a little better fit. The dip in the trans tunnel off the driver's elbow (and thus the ladder bar front-mount location inside) was located by my sitting there and resting my arm where it was comfortable then working around that. A center stuff-compartment and side parking brake lever mounting will complicate all this, later.

Also in the pic, rubber fuel filler hoses, as I start to mock-up/layout fuel tanks (there will need to be a left and a right) behind the driver. Normal cars don't put them all the way in the rear anymore, that's crumple-zone now and my frame rails back there will need to be re-designed for that by-the-way. Fuel tanks and passengers get a rigid area ahead of the rear axle that's supposed to not crush.

So do I really like the idea of sitting that close to fuel tanks off my back? Hell no. Only solution is to make the cage around them a strong one and use thicker steel for firewall.

That driver seat is tending to be the choice accommodation for friends/neighbors who stop by for a brew on the weekends. Mouth car noises optional. Be careful getting up; 'taint nothing but a few wood blocks holding that in place for now.




If you are wondering by now what-the-heck it is I'm making here, this little wooden model on a top shelf in the shop is probably it. I carved this out with a band saw and sanding disc one rainy afternoon when I was in my early twenties (a long time ago) as a "what-if" exercise, and cut the wheels out on a small lathe I had access to on my lunch hour at the time. I did like to do designs, but after awhile, who cares (?) if you can't actually build them which is what I'd rather be doing...I didn't make any more wood models then, and this one has sat on this-shelf-and-that ever since. For to actually build this now I chose a Toyota Supra to base details on because the windshield/side glass is about right, however I don't know how much Toyota I am going to be able to use beyond that. One thing for sure, whatever project I've built in the past (which includes the Challenger etc. as well as the building this work is being done in) is a fraction of what I'm signing myself up for here.



Oh well, I ain't in a hurry anyhow.

[Deaf Bob]

That looks like a nice chassis to plop a Coyote body on..(Hardcasrle and McCormick). Altho hi was a mid engine..