PONY BIG END CLEARANCE

I know, another pony question.  My manual FE030522-02 says the big end clearance for my pony motor should be between .005" and .008".  That seems really large, is it correct or a typo?  Thanks!  Elton D4 7U36219
 

If you are talking about end play clearance on the crank, my -01 book says between .010 to .015 with a max of .025. Do you maybe mean main bearing or rod bearing clearance?

Big end = rod
Gudgeon = wrist pin

If it's in that book, it'll be correct - plenty of editing and checking over 80 years of that spec : )

The -01 book says .005 to .0075 clearance new (same as Elton's -02) and worn out at .013 clearance crank journal to rod bearing.. Worked on the neighbors 6U when we rebuilt the pony and clearance was less than .010 after some 30 years of use. It's an ag tractor (1952) so we went back with std bearings and it runs great. Only thing is it is a rope start.

After having gone this far, I wanted to make sure I was doing this thing correctly. "You can educate ignorance, but you can't fix stupid!" I would rather be educated than stupid. Thanks a lot for your help!
Elton

Hi Team,
yet again specifications for pony engines sheet, form no 12922, dated 6/59.
Eddie B.

remember that is in thousandths of a inch. the average spark plug gap is 25 thou which is approx .85 of a millimetre. make sure your reading the correct marks on the wire feeler gauges.

actually a product called plasti-guage is made just for doing this (note this is usually done before installing the new parts with the crank sitting on the bench or to check if how worn the crank is with new std bearings to know if regrinding is needed plasti-guage allows the average person to check this stuff with out fancy and expensive tools like micrometers and calipers which are a pain to use on round objects anyway, all you need is the product, good lighting and a tension wrench)

to use:
you cut a piece of it and place the piece across the bearing shell so its inline with the crank pin. install rod and bearing assmbly onto crank and tighten to spec.
now remove end cap, remove the now squished bit of plasti guage and compare to the chart on the packet if it matches the desired mark good to go those parts are correct and once oiled can be installed. plasti-guage is available from all good engine shops and auto part stores some bearing suppliers carry it too.

it is always a good idea to check every main and bigend bearing shell against the crank even with a reground crank as you can get bad bearings. i know someone who did for a car engine the supplier had gotten a bad batch 6 sets all of them wrong the bloke had a few choice words for the salesman.