How Close is Close Enough?

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When a fifty five pound flywheel / transmission is turning at 1200 to 1800 r.p.m., the alignment and balance better be more than close.  Did you ever hold a bicycle wheel by the axle and spin it and then try to turn it from side to side?  The gyroscopic force is tremendous! Guess what happens if the crankshaft flange, the flywheel register surface, and the transmission shaft flange are not parallel?  That heavy flywheel, with all of its gyroscopic force, is going to wreak havoc with any misalignment! Usually it breaks the crankshaft.  An out of align fourth main (ball cap bearing) will do the same thing.  Alignment is also critical in Model A crank-shaft/flywheel assembly. 
 
At KMW every part is checked for proper fit and alignment.

​The K.R. Wilson  pan straightening fixture is an absolute must before assembling the engine/transmission unit on the pan.  A bent, bowed, or crooked pan automatically throws the fourth main bearing out of alignment.  This condition must put lateral stress on the transmission shaft which is then transfered to the crankshaft flange. The flywheel, acting as a fifty five pound gyroscope; then acts to straighten the out of align condition and causes undo wear at the third (rear) main bearing and usually breaks the crankshaft.

    How do pans get crooked?  Think about the radius rods. Every bump you go over,  every time you run the front or rear wheels against a curb the impact goes straight to the pan.  




This photo shows a transmission shaft being ground on a universal grinding machine.  Both sides of the flange are ground;  one side mates to the crankshaft and the opposite side mates to the flywheel,  NOTHING is left to chance. 











Left:  Final photos of this operation.  The entire engine is set-up on a Norton universal grinding machine.  The rear flange of the crankshaft is then ground in place whist the crankshaft turns in its own bearings.  Again, NOTHING is left to chance.  Set-up and ground in this fashion, the flange of the crankshaft can not possibly have any runout.  Absolute perpendicularity and concentricity is guaranteed.  



Left:  The dial indicator on the flange tells the story.  No runout!  Another step on the way to a perfectly aligned and therefor smooth-running long lasting engine. 




Contact: 775-883-3324, [email protected]