I'm trying to drill some holes thru the ends of the plate that has the slots that the pins of the weights go thru....

The idea is to tap a small screw in the end so I can adjust the max centrifugal advance possible.

The only problem is that my drill bit doesn't even scratch it. (Same bit that easily cut thru grade 8 bolts for safety wiring).

And also my pin punch for an alignment dipple didn't dipple it either....

How hard is that metal, and what kind of bit do I need. (TiN don't work)

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

You're going to have a tough time...it's case hardened!

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Yep......Like Dan said. You might want to start with a Dremel and small grinding stone, and a very steady hand.

Roger

heat it up, work it and then give it a "false" temper by heating it to cherry red, then drop it in a bucket full of kerosene (be sure to have a cap for that bucket and make it tin bucket)

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Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

You get the dremel carbide bit out

Set up the drill press for highest speed

start to try to grind things away

Hey, it actually made a mark this time

try again,................

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.
.

then all at once you see some powder, then the bit starts to work.....

Now you have a indentation for the drill bit, and are thru the case hardening.

Set the drill press for slowest speed, start drilling away, get almost to the end and break the bit (the case hardening on the other side). Get the remains out (for once the brittleness of the drill bit pays off, it break out in little chunks), resharpen the drill bit, and slowly ever so slowly make the hole.

Now you start on the other side, and it's worse than a repeat of the first side (break the bit 2 more times). You get thru, break the bit for a third time (4 total), and just have enough of the drill bit left to ream out the hole...............

Now I get to tap the hole.

Any bets if I'll break the tap?

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

bets are 2569853321554989756445321213:1 that you'll break the tap. use a shortened tap (to prevent unnecesary stress on the extra unneeded lenght) and if you can, grind the tip of that tap with a longer taper shape.

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Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

Sounds like it might be easier to just make a new plate out of something that isn't so damn hard in the first place.


I'll give you points for persistance.

Who's idea was it to case harden this crummy part anyway?

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1980 Aspen 225 super six

Yep, the tap broke...........

A 2-56 tap is just too weak to tap case hardened steel (you can see it twist....)


New plan........

I'll use my hard-earned holes as centering holes for various gauge wires to do the same thing.............

What I'm trying to do is lower the over centrifugal advance so I can up the base timing (currently 2.5deg) without going to high at the upper rpms. Wanted it somewhat easily adjustable so playing with it would be easier

BTW, I'm getting really quick at removing and disassembling the distributor....

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Ed... I just filled up those slots with silver solder using a propane torch. After that... guess what: no more case hardening... I played with the idea of regulators... but it's way too complicated. Another way to go would be completeing those slots (cutting off the remaining piece of hardened steel with a dremel cut off wheel) and then weld a piece of soft steel hinge tubing and then tap it and fit the regulators... I'm working on that so I'll provide pix as soon as I can get outta bed. (I'm sick as I can be... I have been with "high temp issues" for the last 4 days...)

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Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

like this (hope is clear)

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Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

I have a MIG welder, but my small scale welding sucks...........

I started the hole&screw idea to avoid the welding and then the shaping of the arm only to have it the wrong size and really ugly looking...........

The screw stop idea was supposed to be a quick, and infinitely adjustable solution....

Don't have a spare arm, and need to get the car working, so for now safety wire thru the hole (to keep it centered) and back to the outside and twisted to snug it up (I've done the multiple wraps around the outside section on another old car, and it's hard to control the tightness the actual thickness because of the multiple wraps.... the twisting action of the safety wire snugs it up good)

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Although if you are to do some welding, rather than weld in some softer metal, then grind/shape it, then drill it, then tap it........

Just weld in a threaded insert. Nice premade hole and threads already in it.

Probably should braze it so you don't deform it.......

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Aha! that explains it! I'm a woodwind repair tech so my small fab skills are overdeveloped.... The govnor I'm working on has those pieces lined outa toolsteel stock, then I'm gona silversolder them and cast the heated thing into oil or kerosene. That will harden up the thing again. As far as threading it (or tapping?) I have plenty of very good TITEX swiss SHSS taps that will cut thru almost anything....

your "lazy bones" wire solution's gonna work...

(remember that ole song? Lazy bones.... sleeping in the shade.... howd'ya expect to get your corn meal made...??)

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Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.