Here's my tool rig, from an old post:
"My personal rig for Model B, and I am nearly certain it will fit Model A just as well. Better than the OEM crank because you can turn both ways when working on valves or ignition, better than extension rigs because you can work entirely under hood without having to reach around radiator...
First, you need a socket, and it needs to be 1/2" drive because the 3/4 ones are just too bulky to go in there. Following advice from someone on this board long ago, I found that Sears has a 36MM that is just about right and available everywhere. Finding a real inch one that is not too fat will take more effort...
I then snapped one of the little button adapters Sears sells into the 1/2 drive...this give you a 3/4" nut in the place where the extension would go. This is cheap; it comes in a set of the three most common drive sizes. I do not remember what sears calls the widget but it lives near the sockets in the store.
That goes right onto the crank nut without hanging up on the crossmember or the spring clamps.
Now, you can rotate engine with an open end...but I splurged and got a ratcheting box wrench for the job, giving me easy and reversible turning from right within engine compartment."
On getting it to turn...put your wrench setup on there. Then rotate by giving the wrench handle a good smack with a mallet. It will come loose even if not in gear. This has been known as an Okie impact wrench...
