14-05-2018, 07:35 PM
The chassis I used for our new supercharged single seater was distinctly bowed between the front engine mountings and the first cross member. In addition it had several large holes drilled into it plus three cracks. Clearly a previous owner was a a bit of a fatty who liked to use his electric drill.
I solved the problem by clamping a length of 40x40x2mm into the underside of the chassis rail using some big C clamps. I then welded these into position with 1" tack welds underneath. I had previously drilled out all the holes and run a thin angle grinder blade through the cracks. The square tube and inside of the rails were well coated in Wurth zinc rich weld through primer and I used this primer to slide the tube into the rail when it was all still wet.
I then welded the holes closed by welding the chassis rails to the new box tube underneath, did the same with the cracks. As this was going to be a special on a chassis acquired by Dad nearly 50 years ago, plus I made new engine mountings as I offset the motor, I didn't worry too much about originality in the aesthetics so this solution might not work for everyone.
In the light of your current situation, I'd cut out the repair, then use a section of box tube to hold things straight. Once this is clamped and things are straight you can begin to replace the cut away section of the rail. In your shoes I'd then weld the box into the underside of the rail and the repair to the top of the tube. Once all is straight and welded, I'd then carefully cut away the bottom of the box tubing flush with the underside of the rail. Then weld the edges to the underside of the rail. Now drill the engine mounting holes in the box tubing by just drilling directly through the old holes.
Simple and the Wurth primer will ensure that it doesn't rust and seam sealer will keep the water at bay
Ciao
Greig
Sunny South Africa
I solved the problem by clamping a length of 40x40x2mm into the underside of the chassis rail using some big C clamps. I then welded these into position with 1" tack welds underneath. I had previously drilled out all the holes and run a thin angle grinder blade through the cracks. The square tube and inside of the rails were well coated in Wurth zinc rich weld through primer and I used this primer to slide the tube into the rail when it was all still wet.
I then welded the holes closed by welding the chassis rails to the new box tube underneath, did the same with the cracks. As this was going to be a special on a chassis acquired by Dad nearly 50 years ago, plus I made new engine mountings as I offset the motor, I didn't worry too much about originality in the aesthetics so this solution might not work for everyone.
In the light of your current situation, I'd cut out the repair, then use a section of box tube to hold things straight. Once this is clamped and things are straight you can begin to replace the cut away section of the rail. In your shoes I'd then weld the box into the underside of the rail and the repair to the top of the tube. Once all is straight and welded, I'd then carefully cut away the bottom of the box tubing flush with the underside of the rail. Then weld the edges to the underside of the rail. Now drill the engine mounting holes in the box tubing by just drilling directly through the old holes.
Simple and the Wurth primer will ensure that it doesn't rust and seam sealer will keep the water at bay
Ciao
Greig
Sunny South Africa