Going to have the engine rebuilt on the '19. It has original pistons, rods, and crank. The engine is getting tired. When installing the pan, wouldn't it take the same shape as it is now? Even if it were bent, just the act of re-installing it should straighten it out to where it is now.??
Straightening the pan on a KW pan straightening jig should be a part of any engine rebuild, especially on an original engine that has never been rebuilt. Straightening the pan will undo 98 years of rough roads, engine vibration and sagging just from the weight of the engine block and transmission. It will also align the pan so that it is a straight and true shot from the first main bearing to the fourth main which will cut down on the vibration and strain on the various engine components, especially the crankshaft. You should also replace the cast iron pistons with aluminum pistons. This alone will greatly reduce the weight and strain on the engine. Good luck. It should be fun. Jim Patrick
As Jim suggests, very few pans don't need straightening.
Pan straightening video:
There are a lot of stresses on the crankcase. There is the front ball joint which pushes on it every time you hit a curb or a pothole. Then there is the rear radius rod at the universal joint which can put a sideways stress if you back into something with one rear wheel. Not only those but the weight of the engine and transmission and sagging of the frame or distortion of the frame over the years. Then there is the torque of the low gear or the brake being applied. Any of these can bend the crankcase. The important thing is to keep the transmission rear bearing (4th main) in alignment with the three main bearings in the engine so that runout doesn't cause the crankshaft to bend at the rear flange or upward at the center main. This flexing of the crankshaft is like bending a wire over and over, finally resulting in a break.
Anyway, that is the reason for straightening the
Jonathan: one more thing, if you don't straighten the pan and you apply too much torque on the bolts and nuts to try to bring the pan to the block you can break off the outside of the bolt hole on the block. That don't take a whole lot of torque there are 2 or 3 bolt holes like that on my engine that were that way when I bought the car....I now have another engine in my possession and it will be right when it goes in. As dad always said "If you don't have the time to do it right, when will you find the time to do it over!"
It is my opinion that bent pans are significant contributing factor to broken crankshafts
Aligning the Forth Main bearing with the three main bearings is just as important, if not more important, than making sure the bottom of the pan is flat.
Jonathan: Here are a couple pictures of the before and after of the fourth main surface. Had we reinstalled as you've mentioned most likely would of done damage to engine. Took a few minutes,a little heat and few taps and it's good as new.
Pan straightening. It's a no brainer....mandatory check engine rebuild check list item. Save your self a bunch of headaches later and have it done.
Anyone in northern Indiana provide this service?
I have a pan jig but I am in NW Ohio. 40 miles from the IN line.
Thanks Jack for the reply. Is this something you do?
Yes I do pan straightening. I can be reached by cell at 419-3zero6-3966.