assembling the Model A engine.

Licensed to kill

Well-known member
Wound this video and found it rather interesting. Especially the part about bearing clearances. I don't know if this method is specific to NEW babbit but found his comment about "everything you thought you knew about building engines...forget it". Thoughts on the interference fit of the crank journals??. https://www.youtube.com/watch?v=anDIASMNmCQ
 
I would never, ever, set up an engine that tight! I've had a local babbitter do a couple of engines, and/or just rods for me. I have added a .001" shim to each an every bearing during assembly, and have always had good luck with babbitted emgines. The crank should easily turn in the block. I have set-up rods on the crank before assembly, to be sure they turn freely. I also fit my pistons a little looser than many recommend. On stock or nearly stock engines I bore to .003", then hone another .0005". On my personal engines, even more clearance.
 
The last engine I overhauled had the main & rod bearings at 0.0015" to 0.002", pistons to cylinder walls at 0.002" to 0.003" and piston pins floating. With new rings fitted, the crankshaft in the short block turned below 50 lbs-ft of torque.
The starter motors always were able to start the rebuilt and overhauled engines in my cars, and these engines have high-compression heads.
 
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