Nov 12, 2011
What a mess blow-by makes, an oily firewall, underside of hood and even on fenders. We install breather pipes or steel wool and even rags to slow it down. What causes it? I’ve heard a lot of theories but I didn’t have a clue.
Recently while running a new engine on a test stand, I experienced rough idle and a lot of blow-by. I was really puzzled. Rechecking the timing and carburation didn’t help. My first thought was to tear the motor down. While doing this I noticed exhaust burns on the manifold gasket. I took the manifolds to the milling machine and cut them flat.
After reassembling the motor and running it on the engine stand, I was delighted to discover that the problem was solved. No more blow-by and a smooth idle.
This tech tip was provided by AJ Pennington and was printed in the July 2003 “A” Quail Call.
Nov 5, 2011
Recently I replaced a clutch and throw-out bearing in a Model “A”, which I have done several times before. But this time when the clutch pedal was engaged, there was a loud ticking noise.
After dismantling the whole system again, I found the problem. An obvious mark was seen on one of the four bolts that hold the flywheel to the crankshaft. The replacement clutch has springs where the original did not. These springs help absorb shock when engaged, but does create a clearance problem. The springs were catching on the bolt. After measuring with calipers, I found one bolt head .050 thicker than the other three.
The correct bolt head thickness is .310. The clearance is close, but don’t leave out the spacer ring. It holds the dowel pins in. To help your clearance, the best thing to do is to use a punch and hammer on the flanges next to the springs on the flywheel side only. Normally there is about .070 clearance between the springs and bolts. But if the flywheel has been refaced or cut down to fit the V8 pressure plate your clearance can change.
This tech tip was provided by AJ Pennington and was printed in the May 2003 “A” Quail Call.
Oct 29, 2011
#1. Two summers ago, I went on a Don Harvey day tour to Olean, New York. Starting out in Waterford, PA, my radiator cap broke, so I asked Don what to do. “Stick a rag in it,” he said. “A rag,” I replied? Don replied, “Yeah, a rag.” I thought this isn’t going to work, because all the water will come out. Reluctantly, I stuck a dirty old rag I had into the top of the radiator and away we went. What a picture that was! To my surprise, it worked, with only a little water coming out all day.
#2. As we were returning from Olean, I noticed a slight miss in the engine. After a stop for ice cream and as the group started up a hill, the miss became worse. I thought this is it, I will need a tow back to Erie. I pulled to the side of the road. The engine was missing so much it would barely move the car. Meanwhile, someone radioed ahead to tell Don my car had broken down. Soon he came back to where I was and asked what was wrong. I told him, and without opening the hood, he asked if I had a spare distributor cap with me. “Yes, I did,” I replied. Don said, “Put it on.” I questioned, “Aren’t you going to look at the engine to see what’s wrong?” He said, “I don’t have to.” Ok, I thought. I put it on the replacement piece, started the engine, and drove off with full power from the engine. My question is: How did he know it was the distributor cap? It could have been any number of things, bad spark plug, bad capacitor, points, coil wire, etc. How did he know?
After arriving home, I examined the inside of the cap and discovered a crack, which was shorting out the ignition system.
#3. On the replacement gas caps for the Model A there is a flange on the inside of the cap. This flange is just a little too wide for the cap to fit on the gas tank. It will fit, but is very tight. Being so tight it could result in the rivet holding the flange on the cap to break. If this should happen, the cap will just spin and not come off. If you use a file or Dremel tool to slightly trim the flange and you will have a better fit.
This tech tip was provided by Tom Easley and was printed in the May 2003 “A” Quail Call.
Oct 22, 2011
Editor’s note: This article was recently printed by the Auto Doc in the Columbus Dispatch newspaper.
If you have trouble with overheating in the summer, it might help you cool down to know that straight old ordinary water has more than twice the ability to dissipate heat (thermal conductivity) as common glycol antifreeze/coolant. Our mechanic sources also indicate that a 1:1 mix of glycol has a boiling point of only 15 F higher than that of water (with a 15 psi radiator cap). They also recommend using pure distilled water only in the summer (with an anticorrosion agent mixed in) and as little antifreeze as possible used to get you by for winter. Flush the entire system once a year. Mixing glycol antifreeze at 1:2 ration (instead of the common 1:1 ratio) with water still gives protection down to 0 degrees F. Be sure to check with your owner’s manual before proceeding.
This tech tip was printed in the October 2002 “A” Quail Call.
Oct 15, 2011
The spark plug gap should be .035, right? That’s what I thought. But like lots of others, I tried different things. When installing electronic ignition, it came to my simple mind to try a wider gap. Modern systems use wider gaps with electronics.
.040 was a bust, so I went back to .035. Then Ed Better was showing me an article in Les Andrews’ book that caught my interest. It stated that with high compression heads you should close the gap to .030.
OK, done! This will be my secret until I know the results. I was then off to the nationals in Cincinnati. Wow, an average of two miles to the gallon improvement on my fuel consumption! I then told others and all experienced the same improvement as long as they had high compression heads.
This tech tip was provided by AJ Pennington and printed in the Mar/April 2003 “A” Quail Call.
