Lifter bore ridge

Drewster

Wish I Had A Clone. AKA Andrew Youlio
Joined
May 31, 2001
I can't get the lifter into the bore. turns out there is a ridge at the top of the bore.
I wonder if the block missed a chamfer step at the factory.
Anyone see this before and have recommendations to correct or recommend thinner lifter
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lifters


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It needs to be hit with a lifter bore burnishing tool



Actually all the bores do. After putting hands on one I will never build an engine without that step.
 
Earl Any recommendations on the tool to use? do you knock the ball all the way through or just at opening? The tool I saw said .845 dia which I thought was too wide for the whole bore. But a video I saw the guy used an air hammer and went down the entire bore.
Good idea about the Dremel but I'm at the point of the least debris the better.


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Earl Any recommendations on the tool to use? do you knock the ball all the way through or just at opening? The tool I saw said .845 dia which I thought was too wide for the whole bore. But a video I saw the guy used an air hammer and went down the entire bore.
Good idea about the Dremel but I'm at the point of the least debris the better.


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I knock the ball all the way to the inside, the slide hammer it back out.

The one I use is a Goodson unit.

It's amazing just how well that tool works. Rather than making it 'look' good, or enlarging the hole to make a tappet 'fit', it actually puts the hole back round and burnishes the finish.
 
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That's the tool I use. Notice it comes with three balls. It'll do GM, Ford, and Chrysler (I think).


If you ever put hands on that tool, you'll never assemble an engine without it.
 
My bores had rust in them ( fire sprinkler system) and has to have a BHJ fixture or CNC to put bronze bushings in.:( I wish I could use a tool like that.
 
thanks for the info. I ordered all the pieces separate and only the ball needed to save some coin.
 
Did you have the block thermally cleaned and shot blasted? The shot blast process peens the upper edge of the bore over slightly on most blocks.

I use a Sunnen lifter bore honing mandrel , a truing sleeve and a "HoneALL" to eliminate the ridge. It also leaves a beautiful crosshatch in the lifterbores without taking out a substantial amount of metal. The tools I use are the same tools most pro machinists use to hone lifterbores oversize or finish the bronze bushings to size.

I usually do this operation when the block is still in the cylinder hone tank so I can use the coolant from the hone.

I have thought about getting the Goodson burnishing tool, but was afraid that it might oversize the unaffected part of the lifter bore.

Earl. Have you measured a lifterbore before and after using the burnishing tool? If so, what did you find? I'd be interested to hear your results.
 
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block may have been shot peened looking at the pic, but I bought it from someone who went another direction so I'm not 100%. was definitely magnafluxed. I was thinking of burnishing the top of the bore and checking size before running through. Ill post after checking
 
Earl. Have you measured a lifterbore before and after using the burnishing tool? If so, what did you find? I'd be interested to hear your results.


No, I've never bothered to measure, it works that well.

That tool doesn't make any shavings, it's just kinda "brute forces" the shape back round. Going by feel, the lifter bores feel like a different block after using the burnishing tool. It's amazing how much better the tappet feels inside it's home. Borderline uncanny.
With the amount of people that still insist on using flat tappet cams, this operation might be the difference between an engine living and a $3000 mistake!


With the amount of tooling you have, I recommend that you get one. It'd be nice is someone other than Goodson made it though. They think waaaaaaaay too much of their stuff. I haven't looked to see if you can just get the ball and build your own slide hammer.


....that gives me an idea.... :D
 
Hmmmm????..... I wonder if it could clean up a rusty lifter bore? If not it has to go to another machine shop that has the capability to CNC or hone the bores with the BHJ fixture.
 
Surface rust, yes. It'll knock it right out. If it's serious flaky rust from hell, that would have to get wire brushed first.
 
Worked well. Lifters fit now and still have .0010 -.0012 clearance.


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Hopefully someone with more experience can chime in on lifter bore clearance specs.
Saw a few different clearance specs when searching .0010-.0022 seems to be consensus for GM. However I have a Comp cam guide said .0015-.0020 was MINIMUM to avoid damage.....Not sure of Maximum. I rechecked 2 bore on mine after burnishing and came up with .0016 and .0018. I'm sure excessive lifter clearance will cause pressure loss and bottom end can suffer but I'm not 100% sure what the acceptable lifter clearance range is for Buicks .
 
Its' not so much the clearance as it is the shape. You can have .003" clearance but if the bore is wavy and egg shaped, the lifter will bind.

That's why I don't like the idea of running dingleball hones in there until the tappet 'feels right'. That method means you're removing metal everywhere until the tightest spot frees up. The burnishing tool basically shoves everything back in place (and applies a good finish).
 
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