Old Wive's Tales

BILL WILLIAMSON

BILL WILLIAMSON

Well-known member
How about discussing Old Wive's Tales about Model A repairs that are not based on common sense knowledge & good mechanical skills?
Often I see poor running blamed on such things as, "I think the timing jumped!" Baloney, this doesn't happen unless you broke a tooth on the timing gear or the oil pump and distributor drive gear.
Let's focus on proven ways to diagnose & repair our Model A's.
 
How about the myth that if pistons are installed with the ring gaps all in line the engine will not start due to lack of compression or it will burn copious amounts of oil, etc., etc. Not so!............ ....Some math: A piston's ring land diameter is approx. .030"-.060" smaller than the cylinder diameter so let's say we have .030" space between piston and cylinder wall above the ring gap and a .020" ring gap. That is an area of .0006" sq. in. exposed to compression pressure. Whatever compression gets through that tiny gap has to begin pressurizing the space between the top and 2nd ring before it will escape through the 2nd ring gap. This space is comparatively large and any compression pressure can easily find the 2nd ring gap no matter whwere it is. Likewise with the top rail of the oil ring, no matter where that gap is located. Rings do rotate in their grooves so who knows how often the gaps all line up in an engine's lifetime?!
 
This from another post:

dumb person said:
But.. but.. if the valvechest is cracked what is the worst that could happen? oil leaks? They told me the cracks in the combustion chamber would fill with carbon.
Dad bought a car that had a huge crack in a cylinder wall that had been driven for years until the combustion gasses had carved a huge gap between the cylinders. Bought it thinking it was just a blown head gasket. He filled the gap with weld (arc weld, not sure what type of rod) filed the cylinders round again & replaced the head gasket & that car was perfectly fine for about 10 years. Are all you guys sure about this replacing parts thing?
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Cracks in the valve chamber will leak water into the oil NOT, the other way around. Cracks in the combustion chamber will leak water into the piston and in severe cases into the oil. Any of these will contribute to severe rusting in a very short time. I will say, I know this because of past mistakes made at my expense and customer dismay. What you claim falls into the category of an old wives tale.
 
Another one...never go to a different brand of oil,or a different weight....The motor will start using oil then.
 
The biggest wives tail:

It just a Ford 4 cylinder, you do not have to do anything very accurate when building it. Just put it together and it will work fine.
 
The only thing that Henry changed from 28-31 were the bodies. Everything else interchanges and is EXACTLY the same. HA!!!!!
 
40 Deluxe said:
How about the myth that if pistons are installed with the ring gaps all in line the engine will not start due to lack of compression or it will burn copious amounts of oil, etc., etc. Not so!............ ....Some math: A piston's ring land diameter is approx. .030"-.060" smaller than the cylinder diameter so let's say we have .030" space between piston and cylinder wall above the ring gap and a .020" ring gap. That is an area of .0006" sq. in. exposed to compression pressure. Whatever compression gets through that tiny gap has to begin pressurizing the space between the top and 2nd ring before it will escape through the 2nd ring gap. This space is comparatively large and any compression pressure can easily find the 2nd ring gap no matter whwere it is. Likewise with the top rail of the oil ring, no matter where that gap is located. Rings do rotate in their grooves so who knows how often the gaps all line up in an engine's lifetime?![/QUOTE

If the ring gaps are aligned it wouldn't lose enough compression to keep it from cranking but it certainly wouldn't be a good thing.The rings fit tightly to the cylinder walls. A .020 ring gap is a .020 ring gap and the width of the piston ring land diameter doesn't change ring end gap. All of the new ring sets that I have ever seen or used stressed the fact to stagger the ring gaps. If the ring manufacturer didn't think that staggering the ring gaps made a difference they wouldn't recommend staggering them. I have no doubt that the rings will rotate in the grooves. Will lined up end gaps cause oil burning, I haven't tried it. I know that I wouldn't try it.
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This is not specifically A model but when I was a kid the word was that when a car wrecked the speedometer would "stick" on the speed they were traveling when they hit. This way the cops would know how fast the wrecked car was traveling. Myself and all the kids I knew honestly believed that. I saw many wrecks because my friend's dad ran a junkyard and alot of them had the needle way around past 120 mph. HA HA !
 
"I had one just like this" bla bla bla "Now what year is this one" Im thinking it must be the same year as the one you had right? LOL
 
How about the ole standard, "If you put detergent oil in your old car, you will ruin the engine".
Actually, this did have a lesson to learn. When detergent oil FIRST came out, the engine blocks were sludged up. If you put detergent oil in your car, it would break down the sludge and clog your passage ways. It did lead to ruined engines.
To this day, some people still think that you can not use detergent oil in old engines.
MIKE :)
 
Air-balancing a carburetor when using an air filter is getting to be an old wives' tale. As long as the GAV gives normal responses, the air balance is not needed. The air balance will not take away the air flow resistance of any filter.
 
Ive worked on hundreds of old engines,I have never seen one that the detergent oil instantly scoured out the sludge when used.My grandfather subscribed to that theory.He felt detergent oil will give your engine an instant enema.He put two quarts of it in an old Falcon,a week later the engine came apart.I took it apart after to play with it,when I pulled the valve cover it acted like a jello mold.The sludge was perfectly formed to it,and you couldn't see one rocker arm,pushrod,or head bolt.Almost the same with the oil pan.I got the gasket free,then had to yank the pan off.It was hung up on the sludge around the oil pickup.The engine knocked,ran hot,left a blue haze behind it on the road,but it was that damn detergent oil that ruined the engine.He sold A's new,and to him Ford never made a good car after until they came out with the Falcon.He said the V8's wore out because the pistons laid on their sides and gravity got to them.Myself,I have used Rotella since about 1977 in almost everything.I've had a few motorcycles that I could not use it in.
 
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