1993 Jeep XJ 4.6L short block assembly - Hagerty Media

It high time for assembly to begin on the Jeep straight-six living in the Redline Garage. The steps on a short block go fast, but that doesn’t mean we overlook any essential details. Davin, after all, is never one to take shortcuts. However, sometimes that means taking literal cuts. Stay with us.

The engine block recently returned from a second machine shop trip to re-cut the deck height, and it was  also re-cleaned so it can be ready for final assembly to begin. That process starts with the freeze plugs—and also a few threaded plugs—in the case of this particular engine. Those threaded plugs are a taper pipe thread, which means they don’t technically need any sealant of coating. Davin points out that assembling dry is perfectly acceptable but more than likely will lead to the plugs becoming all but unremovable in the future. A quick dap of teflon sealant will keep them serviceable.

Then it is on to the pilot bushing in the crankshaft, the cam bearings set into the proper places, and then the final torque of the crankshaft main bearings. Toss on the pistons rings and send those into the bores and things were going swimmingly. Almost too smoothly.

The combination of parts Davin uses is all Jeep in origin, but that doesn’t mean they were designed to function together.  The first time these incongruences appear is just as the harmonic balancer is installed on the snout of the crankshaft. The new balancer sits a little further in, and thus Davin has to do some fabrication with the plasma cutter and lathe to make an appropriate “washer” to ensure everything is held properly by the crankshaft bolt. In the end, it’s a fairly easygoing and quick process.

Will Davin keep this pace as the assembly continues next week? We all hope so, but even if it doesn’t you’ll get all the grimy details in the next episode of Redline Update. Be sure to subscribe to the Hagerty YouTube channel to never miss a new episode.

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