I imagine the only people with an accurate jig would be those who make new chassis, Spyder or Banks. The other dampener is that I'd struggle to see how you could accurately check the chassis without removing the body; you can visually check for distortions but measuring it would be difficult.
Spot on, Brian. Pulling the shell is not the most onerous job on these cars, just fiddly. Advantage is that you can get a good look not only at the potential damage, but also whether there is any twist or distortion that may have occurred further away from the instant damage.
On a positive note, you can always measure diagonals across the chassis and that should indicate if it's badly twisted. You can measure wheelbase from centre to centre on the wheel hubs quite easily and compare sides.
String, plumb bobs, drop from the bottom front suspension pin up against chassis, measure to end of opposite rear fork will give you 'squareness' front to back, setting the chassis on 3 of the same size blocks (2 at front, one at y-to-center box, and measuring to floor (assuming floor is level fr-back, side to side) will give you twist (measure at end of rear fork arms, again). Then you can go from there. Luckily, you folks on the other side have shops that know how to work on this frame...over here...we're a little more constrained
One thing that does come to mind is a full alignment check on something like the Hunter setup. If the car was correct pre-impact and is still the same then you're good. If it's drastically out then a good operator should be able to give some idea of where any problems lie if you tell them beforehand why you're doing it.
Again on a positive spin, damage to one part of the rear forks might not be serious enough to change the chassis unless you've got the engine/gearbox out of alignment. Given the rear suspension hangs off the engine/gearbox unit, any distortion should come out in a geo check ?
Brian
Absolutely correct. Can't discount that. Lots of measuring to get the right insight as to what (if any) divergence from the manufactured part was. Assuming your suspension arms, track rods, etc are ok...the only thing that will need rectification if the figures show damage is the frame itself. Actually easier to deal with than if it was one of those glued-together monocoque shells that are the current style. I freaked out the first time I had to do a swap. No argument there, but not the end of the world.
These weren't precision-made (being hand-welded on jigs), but should be within the tolerances that the factory originally accepted as a usable part. Thinking that the repops are actually done to a closer standard these days, 50 some odd years on...just my $.02, having reconstructed a few frames along the way...besides, here's a chance to clean up, refresh, and really set the car to better than what was pushed out the Hethel back door (finances/time/patience allowing). Yeah, shunts suck...but...may be a blessing in disguise to have something at the end that was better than what you started with!
