Lifter bore hone

[Boiler Ben]

I’ve disassembled my short block (see separate post below) and I’ve noticed the lifter bore closest to the distributor has a rough edge that prevents the lifter from seating in it.  I think the assembler must have tapped the oil galley plug there but left an edge in the lifter bore.  What’s the best way to clean this up?  Hoping I don’t need a $50 tool for 3 seconds of use.

https://fepower.net/simplemachinesforum/index.php?topic=12451.0

[pbf777]

      If the issue is as I envision it, just pickup a piece of 3/4" wood dowel, wrap a piece of say 180 grit sanding paper around it, and then with some reasonable technique (important!), and in a barbers' pole twist & trust, including reversing the direction of motion, you should be able to "deburr" the oil gallery intrusion relatively simply.  If the sum of material displacement within the bore is anything greater than that of just a "deburr" operation then the block should be taken to a proper machine shop, who has a proper honing mandrel (not a "ball-hone"!  ) to square it up.   

     Oh, and that "proper honing mandrel", well, it costs significantly more than fifty-bucks!   

     Scott.

[Boiler Ben]

Thanks Scott. I think it is definitely a deburr situation. If I understand correctly, the technique is kind of a corkscrew motion down and back?

[WConley]

If you just need to deburr the bottom of the hole, a hand tool like this could work.  The triangular cutter pivots so you can slip it down the bore, then flips out underneath.  You need to check the size of the tool vs. the lifter bore:

https://www.amazon.com/NOGA-Reversible-Tool-Holder-Set/dp/B002NERHN4

[djburton]

Just went through this. Did what Scott mentioned and the lifter dropped in fine but I noticed some thin metal around the edge of the oil hole that I wanted out of there. With my luck it would have broken off and somehow jam up the lifter. I made a small deburring tool and ran it through the front of the block. The device WConley posted would work great if small enough diameter and long enough to go all the way through.

[blykins]

Depending on the burr, you can also take an old lifter, cut some grooves in it, weld a bolt to the top of it, and use that to break any burrs free in a lifter bore.

[pbf777]

If I understand correctly, the technique is kind of a corkscrew motion down and back?

      Yes, including a wiping motion across the area needed dressing.  This process should highlight the offending raised surfaces but also the factory's boring machining marks which can provide as a guide for what effect your having in the endeavor.  Caution: do not be overly aggressive, just knock the high spot down and stop!   

       For the purpose of deburring such as on the oil gallery junctures, I often will utilize a die-grinder and sanding roll with the trailing last wrap peeled feel of the barrel, this to create a flexible "flap-roll", this mounted onto the mandrel length required to reach into the gallery pathways.  Again, with proper technique can make for quite nice radiused edges.   

      Scott.

[Boiler Ben]

I am still having trouble with this. I tried what Scott suggested and the lifter does drop in a little lower now but it’s still getting stuck. I’m attaching one photo from below, through the front cam bearings, and another photo from the top. You can see a little gouge and the lifter gets stuck there.  Just using my finger, it doesn’t feel much different than any of the other lifter bores but it still isn’t good enough. Any ideas to try next?  A brake cylinder hone?  I’m also including a top view of the other side of the bore showing the tapped threads and slight imperfection there too. Again, doesn’t feel extreme at all. 

[WConley]

That's such a small raised edge, that I would probably use a Dremel with a small carbide burr (ball) to gently hit it.  A stone cutter would work, but leave a lot of gritty dust everywhere.  I'd go for the carbide. 

With my old eyes, I'd have a jeweler's magnifier on.  You need to have a steady surface to rest your tool hand on as well.  Would be a pretty quick job.

[Boiler Ben]

I’m going to give it a try.  Thanks for the suggestion.

[Boiler Ben]

Carbide ball worked great.  Just needed a slight touch.

[WConley]

Great to hear Ben!   Looking forward to more updates on your build. 

- Bill