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Old 10-20-2020, 08:23 AM   #16
BRENT in 10-uh-C
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Default Re: Time lapse Model A engine build

Quote:
Originally Posted by Licensed to kill View Post
Are you saying that the assembly of the engine in question was done correctly being assembled as tight as it was (in the other video of the assembly)?. I ask because, as i remember there was a LOT of dissension among the ranks regarding the tight tolerances used on the bearings which surprised me as i would have thought that they guys from Hagerty would know the proper procedure prior to assembling the engine.
Often times in specialty topics such as this, jealousy and personal agendas tend to overshadow facts. Dissention is often the results.

While I have not reviewed the video in awhile, as I recall, they towed the 'tight' engine for 20 feet or so and the engine started. I don't recall any sliding the drive wheels because the engine was so tight, or jumping up & down on the hand crank because the engine would not turn. As I stated earlier, the Ford-approved procedure was to burnish the cast bearings. I doubt there are a handful of us engine rebuilders that do this operation today. For the ones that choose not to burnish as part of the rebuilding procedure, then setting clearances up a little tighter and allowing the cast bearing to fluidize during the initial starting is likely the next best way.



Quote:
Originally Posted by duke36 View Post
How about the red coating (some builders use this) which looks like Glyptal from past decades, that's inside the block ? Can that come off and / or does it block passages in any way?
This topic has also been discussed at length here. "Can that come off and block passages..."? Yes it can, ...however it usually does that when the insulating varnish was applied poorly. Some rebuilders never have this become an issue on engines they rebuild.

This controversy (IMHO) stems from the facts that not all engine rebuilders have a good way to clean parts. And, ...not all engine rebuilders take the time to thoroughly clean all the parts. The cleaning process when done correctly takes time and requires a large financial investment to have the proper equipment. I personally have a 3 step process in 3 separate machines that takes it from greasy to clean. It really should not matter whether the cleaning process is done thermally or by chemicals as long as the oils are completely removed from the pores of the cast iron. Residual oils in pores, crevasses, or obscure corners are what causes the varnish not to adhere properly. Get them clean where the varnish can grip into those pores, and you will find it is very difficult to remove it during the next rebuild.

Just so we are clear, the main reason for using varnish (-such as Glyptol which is still available) is for insulation and oil control. Rust prevention is secondary or even thirdly. Windage inside of a Model-A engine is pretty rampant which affects the engine oil location and temperature. Having a smooth surface where the oil does not cling to that surface is ideal. This ultimately places the oil back in the pan where it can be cooled. Varnishing also seals the metal pores where any suspended debris cannot attach itself to. This debris can be anything from the cast iron being scraped off of the cylinder walls due to friction, to piston rings being abraded away, to metal wearing off of a camshaft lobe or tappet, -or just general carbon & coked oil. As far as insulating properties, consider what is being transferred into the valve chamber are through the roof and backside of the chamber -and why. While some argue the effectiveness of the insulation, I feel it really boils down to whether it is a value to you, and what level of quality you are seeking for you engine. Are you wanting the best you can have, -or is mediocre acceptable for your engine?

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