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Old 02-20-2018, 10:05 PM   #13
Kohnke Rebabbitting
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Join Date: May 2010
Location: 60615,330th Ave.,Clare, Iowa, 50524
Posts: 1,454
Default Re: Oil viscosity (weight) for model A

Our conclusion is that the use of the higher cost Synthetic Multi-Grade 10W-40 Motor Oil for newer Model A engines is justified since it has a benefit in terms of a higher temperature margin for preventing cylinder wall scoring. " END QUOTE "

Higher Tem. Margin, OK. But cylinder wall Scoring comes from pistons fit to tight. I have seen that hundreds of times. Never set clearance to what comes in your piston box!

The oiling of the cylinder walls is accomplished by scoops (dippers) on the connecting rods. These dippers pick up oil from the corrugated sheet metal pan and create a "fog" of oil that lubricates the pistons and cylinder walls. " END QUOTE "

Oiling of the cylinder walls, done by dippers, NEVER, the dippers are there only to oil the rod. What puts oil on the cylinder walls, is the crank, and the rod as a whole, kicking the oil out of the dipper tray.

I have heard many times that the two holes in the web, are there to oil the cylinder walls. NOT TRUE, they are to relieve air, and oil locks that would take place in the top of a dead end X groove.


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