HOW  LOW  CAN  YOU  GO?
Another test of 1/4-inch [6mm] OD Titanium tubing, about as deep in the
tailpipe as we could figure out how to place it. The bent end of the tube
was turned down, so that the top of the vise could be dropped as low as
possible [actually lower than it appears from this viewpoint]. With the
vise this close in, it was impossible to start the engine with the jaws
higher in relation to the rear opening of the tailpipe.
Photo Copyright 2003 Cottrill Cyclodyne Corporation