Fortunately, it looks as though the engine in my Lemons-racing Volkswagen 411 wasn’t damaged as badly as we may have thought. Two cylinders had normal, good compression! But the two cylinders on the passenger side did not, and one cylinder with no compression at all was thoroughly mangled.
The more I learn about aircooled Volkswagen engines, the more I like them. They’re brilliantly modular. Whole cylinders of the engine come off, so if one’s bad, you can just replace it, provided it’s balanced with what’s going on with the other side. Many opt to replace all four pistons and cylinders at once because they’re easy enough to do, and why not? Anyway, that’s what I’ll need to do with the pistons and cylinders for one side of the engine.
One thing I have learned, though, is that these engines do have a cooling system after all—which we weren’t running at all when we raced the car. A series of tins surrounds the engine to funnel cool air in to the engine’s most important bits, and keep hot air from the exhaust underneath from coming back up.
We simply didn’t have most of these tins when we raced the car, as you can see by the amount of daylight peeking through the engine bay. It went 104 laps like this. Yikes.
Fortunately, it seems like it didn’t damage much else, if anything, that I can see. We had an oil temperature gauge in the car and kept bringing it in when it was getting hot throughout the race. Maybe—just maybe—that saved us. The engine technically ran when we pulled it‚ just poorly.
When the passenger side of the engine had 52 psi of compression in one cylinder and none at all in another—and normal should be closer to 100—I started disassembling that side to see what was up.
The head didn’t seem to leak from either side, so it seemed fine. Then we looked at the cylinders themselves and found some big problems. The piston in cylinder No. 1—the 52 psi one closer to the cabin—was scraping a bit on the side of the cylinder wall.
But at least its piston rings still moved around some, as piston rings should.
The zero-compression cylinder No. 2 was the more morbidly fascinating one, though. Just look at this once-hot mess.
The piston rings were completely scraped and melted together into a solid, un-springy mass, and the top wasn’t even round anymore from bits that had ground off.
Piston rings are pretty important, as they seal the combustion chamber in an engine and keep the fuel/air mixture from blowing by the piston, for one. They also help regulate oil consumption by scraping the cylinder wall. This could explain all the oil that oozed out the passenger side of our car, then.
One theory is that because oil gets thin when it gets hot, it may not have been properly lubricating this side of the engine, leading to the piston rubbing the cylinder wall like this.
Charred oil was all over the bottom, looking a bit too much like burnt cheese as we pulled these way too close to lunch time. (Mmm, pizza.)
If anyone has a couple of working pistons and cylinders for a 1700-cc stock Type 4 engine or even just a running engine nearby, please, for the love of all things holy, I need them as soon as possible. The car is still supposed to race on November 11-12, and I’m starting to run out of time.