My 1948 Willys—nicknamed Project Slow Devil—has been dead since its engine lost all compression on a rural Kansas road. Time of death: Saturday morning, 1 a.m. Ever since, I’ve struggled to get even a wink of sleep as I tried diagnosing the problem. But on Monday, after having a second look at the innards of the Go-Devil motor, my coworker Freddy and I finally found the culprit.
The first thing I thought when I heard my engine turn over after it croaked that fateful night in rural Kansas was that something had happened to the timing gears—it was the only logical way that all cylinders could simultaneously lose compression.
So on Saturday, Freddy and I towed the Willys to Walmart to have a look inside the timing cover, only to discover gears that looked perfect, and valves that seemed to move up and down just as they should. This made no sense to us, and it made no sense to lots of other internet-ers as well.
My Twitter, Instagram and Facebook blew up with wrenchers who swore they knew what was wrong. Many mentioned the head and head gasket, others mentioned rings, and some mentioned valve seats.
None of that really made sense to me, but I was admittedly confused by the fact that the gears not only looked good, they were also moving the valves up and down at what looked like approximately the right point in the combustion cycle.
Since I had been very concerned about my cylinder head before ever leaving on the journey (I had to basically hang off a crow bar to get it off my block), and because it leaked quite a bit of coolant, I figured I’d find one somewhere. I strongly doubted it would fix my problem, but I put out a message on one of my favorite Willys Facebook pages anyway, asking if someone near Denver had that heavy chunk of iron sitting around.
A guy named Lew, the president of the International Flat Fender Club, contacted me and put me in touch with someone named Eric, who told me he’d just leave a cylinder head leaning against his shop for me to pick up at my leisure, free of charge. It was an incredibly kind gesture for which I am immensely grateful.
When Freddy and I got to the shop, a man named Ray—who owns a gorgeous Ford GPW—invited us in, and helped us clean up the cylinder head.
Eventually, Freddy and I chucked the new head in at O’Reilly Auto Parts and, while it did seem to sound noticeably different than before, the engine still didn’t make enough compression:
“Screw this, let’s pull the timing cover again and have another look,” I decided. So we did. We had to peer very carefully, but we found the culprit, and boy was I happy:
Very, very happy:
The fiber camshaft timing gear separated from its metal center hub. This was a failure that even the most experienced of flat-fender gurus had never seen before, but it makes total sense.
The timing marks on the gears are still lined up (of course they are; timing gears don’t “skip” like timing chains do), making it seem like valve timing is on point. But timing is actually off, because the crankshaft timing gear is able to rotate the cam gear without doing its job of actually spinning the camshaft to actuate the valves at the right time.
It’s a fascinating failure, and one that reminds me of a wrenching philosophy that I could stand to follow more often: the simplest and most obvious failure mode is often the right one. You just sometimes have to look a bit harder to find it.
I’ve got a new timing gear coming into Grand Junction, Colorado tomorrow afternoon. After I pick that up and swap it in, this little Jeep should fire right up.
Off-road trails of Moab, here I come!