Today, we did a test run of the engine from MN.

Previously, I'd looked up the various casting numbers. It seems that although this had been recently pulled from a passenger car, it is actually a 1955 second-series pickup engine. The paint color threw me, as I was expecting blue for a passenger car, or gray for a truck. Perhaps this was a rebuilt engine (wrong color of green for a Jasper engine) that was installed in the car.

The engine has a Rochester carb with automatic choke. The starter, fuel pump, distributor, ignition coil, and plug wires are all somewhat recent replacements. Someone split the exhaust manifold between cylinders 4 & 5, so there are two exhaust pipe connections (it seems rather well done). The 3-speed transmission currently on it does not have overdrive.

The oil filter is pretty clean inside, but the rocker arm area is a bit grimy in places. I wanted to start the engine with the valve cover off, so we could ensure everything was getting oil. With a bottle of gas and a little starting fluid, the engine started right up. That split exhaust manifold sure has a different sound than my truck! We only gave it a couple of brief runs, since we didn't have the cooling system connected.

I'm glad we had the valve cover off, because we noticed a problem with the #1 exhaust valve spring. The spring does not quite close the valve. When the rocker arm is at it's highest position, there is still an excessive gap between it and the stem. I can pull the spring upward, and close the valve. I also noticed a lot of lateral play with the valve stem, even when the rocker arm is compressing the spring. Oddly enough, I can't hear a miss, and the #1 spark plug is only slightly more sooty than the other plugs. Here are links to a couple of short videos showing the problem:

#1 Exhaust

#1 Exhaust Compressed

Am I looking at a badly-worn valve guide? If we hadn't had the valve cover off, I would have not noticed that anything was amiss. It's hard to say how long this engine has been running this way. It's difficult to be certain, but the spring looks a little different from the other exhaust springs...is it possible that the spring was replaced with an inexact replacement, and has worn out the valve guide?

What does the brain trust think?

-Kevin
Attachments
Engine Run.jpg (367.59 KB, 138 downloads)

Last edited by Shakey61; 05/16/2021 5:06 AM.
This is what happens when you live with a house-full of women, the wife and daughters name all the cars:
1960 Impala - "Frankie" (Frank Sinatra)
1961 Apache - " 'Mater Jr." (wrecker)
1965 Corvair Monza Convertible
1967 C20 "Ol' Blue" (hidden in a log cabin for 30 years)
1972 SuperBeetle Convertible - "Juliet"
1976 SuperBeetle Convertible - "Olaf"
1988 Alfa Romeo Spider Veloce - "Romeo"