Old News
I picked up a new project car, a 1972 Corvette Convertible in late December, 2005 and have been disassembling the car since then. I am in the process of removing the body and completely stripping the frame. I am going to have the bare frame chemically dipped/stripped and then e-coated inside and out to prevent any future rust. I am also going to have the entire frame powdercoated semi-gloss black.
So far I have removed the entire front clip from the rest of the body. I am going to replace it with a brand new, jig mounted, press molded, one piece front end. I have also removed the windshield and stripped out the interior. For a car almost 35 years old, the frame and birdcage are in suprisingly good shape but I did find some minor rust in the windshield frame that I am currently in the process of repairing. I replaced the windshield frame top, top corners and sides with a brand new pieces from Paragon Reproductions. I also cut out the bottom corners along the factory welds and panel seams and am replacing them with good panels from a donor frame I bought off of eBay.
Luckily, the rust damage is limited to this area and the rest of the birdcage is in excellent condition. The body mount pockets located behind the kickpanels are an area that is commonly rusted out but mine are in great shape. I was able to remove all the body mount bolts on both sides of the car with very little effort. I have already fabricated a pair of body braces to prevent the body from flexing, cracking, and possibly breaking when I remove the convertible body from the frame. I cut a piece of 1"x1" square tube mild steel to fit each door opening, bolted each piece to the top door hinge receiver flange, and welded a tab onto the other end of the tube, and bolted it to the door jamb striker bolt retainer. This effectively ties the two ends of the birdcage together and will prevent it from breaking under it's own weight. I already bought a body lift kit and am ready to lift the body off the frame.
Here are some pictures of the windshield frame areas I had to cut out.
Left Side...
Right Side...
Prior to cutting out and replacing the windshield frame itself, I welded several pieces of steel tubing and rod to the body brace I installed previously. I welded two pieces of steel tubing to the windshield top frame to support it in place while I removed the sides of the frame. I also welded two pieces of steel rod to the body brace angled up to the top corners of the windshield frame in order to provide a reference for the windshield frame rake and width. Additionally, I took several measurements of the original windshield frame to ensure that the new frame is dimensionally accurate and located properly in relation to the rest of the car. While there is some tolerance between all the individual panels, windows, doors, etc, accuracy will ensure a proper fit and reduced wind noise and water intrusion. Regardless of all of this preparation, needless to say, I was still nervous about cutting out the windshield frame. A mistake during this repair could be expensive and time consuming to fix since I won't detect it until after the car is painted and I reinstall the doors, windshield, and convertible top. I still have the original windshield so I will verify it's fitiment prior to finish welding the frame.
In order to determine where to cut the side frame, I measured the length of the replacement frame and compared it against the original frame. I determined that on my car the cut should be made 19 1/2" from the top corner of the frame. After marking the location of the cut, and taking a deep breath, I put the Sawzall to work.
After preparing and cleaning the area and the replacement side frame for welding, I carefully located it in position based upon the measurements and braces I had previously made. The new side frame is supported by the braces and magnetic welding supports.
I tacked the side frame in place with my TIG and verified that it is positioned correctly. At this point I only tacked it enough to position it firmly, but not enough that I couldn't make adjustments to it if necessary as I continued along with replacing the entire frame.
Next, I moved onto the right side of the car and repeated the process...
I was initially going to tack the top corner pieces to the side frames as was done when teh car was originally built, according to the Assembly Instruction Manual (AIM). When I test fit them against the frame top, I realized that the corner pieces were not stamped with the same contour and sharp corner as the top piece so I decided to install the windshield frame top first. Based upon my previous measurements, the original frame inside top corner was 19 1/2" high compared to my reference point, which was the cut line at the bottom. Again, I tacked it in place with my TIG after carefully positioning and clamping it in place. When the new windshield frame is fully in place I will spot weld all the pieces together, replicating the factory welds and assembly of the frame.
In order to create the correct contour and sharp corner, I decided to modify the corner pieces by partially cutting them and bending them to match. After it is tacked in place, then I will weld up the cut I made.
The gap was still not perfect, but I can fill it with weld and create a seamless frame that will not allow water to get inside of it.
With both sides and top corners in place, I went back and fully welded everything in place. Additionally, I decided to fully weld all the seams between the individual pieces that make up the frame. This well totally seal it against water intrusion and prevent it from rusting on the inside. I am going to treat and paint the exterior of the frame, as well as the inside in the lower corners, with POR15 paint to further aid in preventing future rust.
For the engine, I decided to use the new World Products Warhawk LS7X block featuring a 9.800" deck height and a 4.125" bore. With a 4.00" stroke I can use 6.600" rod and still maintain a boost-friendly 1.200" compression height piston, yielding a nice 1.65 r/s ratio. Unfortunately, it appears it is not available yet and is on backorder...I called World Products yesterday and was told that the LS7X blocks and heads would not be available until March, so there's going to be a delay in getting my engine program going.
The Warhawk LS7X block is constructed of 357-T6 aircraft aluminum alloy and features 2 additional head studs per cylinder (6 per cylinder total). This is what really convinced me to spend the extra money on this block versus just going with the 6.0L cast iron LS1 block, plus the aluminum block will offset the weight added to the front of the car by the turbo system. I had pretty much ruled out using one of the production aluminum LSx blocks due to the risk of lifting heads or blowing head gaskets since they only use 4 studs per cylinder and there have been reports of pulling/stretching the threads in the block. My last 427TT made between 22-25 psi of boost and I'm planning the same for this one, maybe a little more.
The LS7X block also has both the LS1 and SBC motor mounts cast in, so no worries about using adapter mounts or relocating the mounting ears on the frame. It uses the same billet steel main caps with 200,000psi ARP studs/bolts as the C5R, priority main oiling, dry sump compatible, and will take up to a 4.250" stroke. It uses standard LSx series accesories.
For heads, I am going to use the Warhawk LS7X 12* heads. They also accept the 2 extra heads per cylinder and feature 255cc intake ports with 64cc C5R chambers. 2.200" intake valves and 1.625" exhaust valves. My first TT 427 featured 257cc intakes runners and 2.180" intake valves, with the same 1.625" exhaust, so I'm expecting similar flow numbers of ~ 380cfm at .700". We'll flow bench them when we get them to confirm. The LS7X heads utilize standard LS7 valvetrain components, but I'll probably use Jesel shaft rockers again and either Jesel or Isky roller lifters.
The only downside so far to using these parts is that they won't ship until at least the end of January I am told, so there will be a little bit of delay in actually getting started.
Previous Projects...
Pics of my first turbo engine project....
Here's a little video of me getting squirrelly accelerating from about 4500-5500rpm, and building up to about 7 psi of boost. The boost controller is totally closed, and I swapped out the 20# wastegate springs for 5# on the street. It's still tuned for the 20-22 psi I used on the 1200hp dyno run, but I'll use the softer springs on the street and raise the boost via the controller if I have to - which I can't see doing anytime soon! As it is, it's a real handful, and I still haven't even got into it or spun it past 5500rpm or so on the street. You can faintly hear the BOV's "swoosh" at the end, but I had the t-tops off this time and the camcorders microphone is getting washed out by the wind.
I need to get better video editing software, the package that came with my Sony camcorder sucks. I stared off with a 1:15 minute rcording that was a little under 8mb and edited it down to about 15 seconds and the file size grew to 32mb. This one is 5 seconds and a little over 3.5mb.
Test Run 1
Here's another one, you can definitely hear the wastegates and BOV's in this one.
Test Run 2
Here's the full "shakedown run" video. It's not much in terms of the potential of the engine, but here it is.
Full Test Run 1
Below are a few shots from the dyno testing and tuning session last summer at
