July 5, 1008

When we pulled the engine from the Banzai Runner, Rich noticed the sparkle of metal in a pool of oil in the head. This got me curious to see where it came from.

July 16, 2008

Well, tonight, I figured it out...

When I dropped the pan from the engine, I found this grey "muck" in it. But it wasn't sludge. I stuck a magnetic screwdriver into the stuff and found that it was metal.

This made me curious to see how bad the bearings were. The engine developed a rod knock on the way home from last year's Monterey Historic Races, but I never could have imagined what I'd find...

Rod bearings are important in an engine, and it's always good to have them. However, when I removed the #1 cylinder cap and rod, THERE WAS NO BEARING!!! That's right, there was no bearing present; and no signs of a bearing (at least intact) anywhere in the engine. And, the underside of the piston was beat up from hitting the crankshaft counterweights. Apparently the additional play between the rod and the crank journal allowed the piston to drop into the block far enough to allow it to get hit by the rotating crank counterwights - never a good thing!

And what might you expect the crank journal to look like? How about 1/16" worn way...

And as you would expect, all the remaining bearings were very worn, rather they are shot. Here are a few of the rod bearings - worn and scarred.

Here are the main bearings, also very worn. Notice that's a sliver of bearing material lifting from the face of the bearing in the 2nd picture from the right below.

Other notable observations... All of the lifters are worn concave. They're supposed to be convex.

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