I am beginning to restore my 1909 Touring. The car has the wrong frame under it right now. I purchased the correct frame for it and when I checked it out I found it to be about 5/16" out of square. The "new" frame was used as a hay wagon and the front crossmember was loose on the passenger side. I removed the crossmember with the intent of re-riveting it back on. Can I cross clamp the frame pulling it square and then re-rivet the front crossmember in place? Any suggestions?
Check and make sure the frame is not sagged before you call it "Done". It should be easy to pull it square....try a Come-a-long. You will need to pull it further than what it needs to be as it will "Spring" back. Do not try and do it all in one pull....it normally takes several pulls to get it square.
I have tie downs in my shop concrete floor and have corrected numerous bent car frames.
How much of a crown should there be in the side rails?
I've heard about a 1/2".
The upper flanges were completely flat originally. A 1909 body is fairly light, so it shouldn't sag much in service.
Here's John Regan's frame drawing that's correct for 1909-13, but works up through 1925:
The frame should be straight along the top edge, as Roger said. Most frames today have some sag where the crankcase ears rest on them, so they need to be straightened. I've never heard of intentionally adding a crown to the frame rails.
George, I think a slight crown is better than a slight sag.