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.....about an F-134 in an M38A-1. I just got this engine back from the machine shop and was going through the motions last night of getting it ready to paint. After mounting it in the engine stand I was removing the protective wrapping from the block and noticed something strange. The two expandable plugs installed on the passenger side of the engine appear to be installed what I would call correctly....with the cup edges facing inward toward the engine. The larger expaning plug installed at the end of the camshaft journal on the rear of the engine appears to be installed backwards.....with the cup edges facing outward. I've looked in the engine manual for installation instructions (since this would mean that the plug would need to be expaned from the inside of the engine) and at the parts pics for visual guidance but they both seem to support that the plug should be installed with the cup edge facing inward. So.....does the machinist know something I don't know......or was there a revision issued somewhere to turn this cup around......or have I caught the guy in an oops.....and need to get the plug turned around? Thanks for all the help.

Jim

This is the correct way:

okay.....so quick answer is.....there are no quick answers? Is that an L-head......cause you got twice as many expanding plugs as I got....in both locations......side and rear. The one I'm interested in is the large one located at the rear of the camshaft gallery......the one hidden by the rear engine mounting plate. It almost looks like yours is installed with the cup lip out too....but I'd need a closer up pic to tell for sure. Thanks for the reply.

Jim

The plugs are installed the same way on both engines. That's an early M38 L134 which has 4 plugs on the side and one at the top rear. The later M38 and the later F134's only have 2 on the side and none on the back for the water jackets.

The plug in the rear cam journal bore is not the same as the others. There are several different kinds of welch plugs. Some with a outer lip and some with no lip. Most outer lip type go in rounded edge first leaving the lip showing. The clue will always be the same on how they go. The raised center always faces you and when it is in position you dimple the raised centeraway from you to set the edge of the plug.