Cracked lifter blocks

[Tunglegubbin]

I preparation for getting my OEM cast iron lifter blocks machined for oversize lifters, I started to clean them a little.
Upon inspection I found that one of them has been sanded smooth (preparation for chrome plating?)
On two of the fastening holes there is a crack from the hole to the edge.
The lifter block is sanded down in that area as well but not so much that I would think it's integrity has been compromised.

My suspicion is that someone has used screws for counterbored holes in a countersunk block?
Would that wedging cause this?

Scouting ebay for a better candidate it seems to be a common fault.

Anyway I soldered the crack with silver solder and it looks good.
But if the original material did not stand up for this, does my fix?
Is it worth spending further machining on?

Furthermore I tried to clean up my soldering by running a countersink bit, but it seems to be something else than 90°.

/Mikael
Does anyone know what the countersing angle is on a Harley fastener?

[58flh]

Tunglegubin!---I have repaired a few cast ones by -v-ing slightly with a Dremmel & using JB-weld!---It Works!,Some are on thier 4th year in heavy-daily service!--As to your ? The wrong bolt will def. do this!-Also the Blocks dont need to be Tourqued to hell!--12-15lbs is PLENTY!--I have one on mine that was split when I purchased the cast-guides!--Sure enuff the wrong screws were used & that caused the split!---I have repaired this guide over 20yrs. ago-It was 1-bolt-hole & its still running today!-& I use mine daily!-(weather-permitting).--If you have 2 holes that have been split on the same block,-You should be fine with v-ing it a little & soldering like you did!--As far as the angle or curve of the bolt needed for your blocks -I dont know!---But IM sure others will know!---I took a guide & matched the bolts to em in a dealer of Fasteners & the like!--I then ordered the correct thread & Length.---Good-LUCK----RICHIE

[RUBONE]

The outside corners of many stock blocks are sanded/ground by the factory as part of the production process to eliminate excess material. They are all also prone to cracking at the mounting holes, especially the aluminum ones. One of the common ways they are broken is by guys using the screws to pull the blocks into the case. Many are a slight interference fit and warming the case before assemble helps. Another way they are broken is when guys try to pry up the corners to get them out. They are fairly easy to fix so not too big of an issue. As far as the angle I must say I have never checked it, I just ground a drill bit to match the screws and went from there.

[Larry]

If your "silver solder" is in fact "silver braze", the repair will be nearly as strong as the base metal, provided the iron took the braze properly. I believe the angle of the screw is 82 degrees, a common countersink.

[Tunglegubbin]

You never stop learning things.

Countersink angle for metric and english fasteners is 90°
American fasteners are 82°

...and ebay hardware stores has them.