4.2 engine crank sludge plugs

XK-Engine
1

Good day to you all.

What size allen key hex head fits the sludge plugs in the crank shaft on a 4.2L engine.?

Thanks Lee

2

They are 1/2” on mine. I just had them done, and the machine shop had to drill the old ones out and retap the holes.

Note the tap is an unusual 5/8-14 BSP, but I was able to source one on eBay from Britain for a reasonable price.

3

Got the head all rebuilt?

4

Good to point out the tap needed. BSP is international standard for plumbing/hydraulic except for quite a bit of North American applications using NPT instead. Some overlap on threads, but not much else. BSP is available many places in the US but caution on identifying correct tap is right step.

5

I had been focusing on the bottom-end, but I finally tore into it the other day. I found that one of the tappet guides was dickered, but I was able to pull one out of my old head. Need to start measuring everything to see what it actually needs, but so far, so good.

Hope all is well.

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