What type of drill bit do you use on a cam gear?

James Montigny
07-19-2006, 12:01 PM
Got the timing set, got the bushings.
What kind of bit do you use to drill though this stuff?
That's some tough looking material.

I really don't want to end up buying a bit that costs more than the custom cam LOL.

Javier97Z28
07-19-2006, 03:06 PM
I'd use Cobalt bits as they seem to be the strongest.. and to be honest this is something I'd probably do in a drill press, not a hand drill. I have access to one tho, so it may not be an option for ya.

James Montigny
07-19-2006, 03:17 PM
I'd use Cobalt bits as they seem to be the strongest.. and to be honest this is something I'd probably do in a drill press, not a hand drill. I have access to one tho, so it may not be an option for ya.

LOL, I did not intend to do this in my back yard with a hand drill.:p
And I'm certainly not using a carpenter's drill press on this.

The car is at a shop with a press designed to make this type of precise
bores. It's just a matter of getting the correct bit. They did not feel that
anything they had was going to work well with this material.
Hopefully, they've located the bit by now. I'll talk to them later tonight.

BTW, your PM box has been full for a while.
How can I harass you if you can't receive messages? :D

MachinistOne
07-19-2006, 08:45 PM
Colbalt bits will hog through just fine, just dont overspeed the bit...that is the most common mistake people make - if it aint making streamers or at least chips, you're doing it wrong.

jerminator96
07-21-2006, 08:54 AM
Gary,

As a toolmaker you had access to a machine shop of some sort i'm sure. Now would you risk damaging an expensive piece of whatever that you had just bought because you were too lazy to set up a drill press? Just because it can be done doesn't necessarily make it the right way to do it.

Just my opinion,

Jeremy

James Montigny
07-21-2006, 02:37 PM
The cobalt bit couldn't touch it LOL
The machinist told me that it's "sintered" (powdered metal) forging.
He ended up using a titanium nitride coated carbide steel bit
submerged in a high grade oil.
It boiled the oil and the dust came off like gray baby powder.
That's some tough metal.

The timing set went back on without any problem.
The new chain doesn't have the play the old one did and everything lined up.

Hopefully I'll have dyno numbers by next weekend.
Thanks for the replies, if anyone ends up having the same issue
they should find this thread useful.

Javier97Z28
07-21-2006, 06:08 PM
James, I made some room in my PM box.. sorry I'm popular! :D

If I could pay more for even more than 250 PM's I would lol

MachinistOne
07-21-2006, 08:56 PM
Well I figured that the colbalt bit would eat through no problem if run slow and with cutting fluid:( .... was it a GM gear? Cloyes?

s10er8
07-21-2006, 09:32 PM
At the price that shops charge for labor you should have just gotten an adjustable timing chain set and been done with it

http://www.jegs.com/webapp/wcs/stores/servlet/CategoryDisplay?storeId=10001&catalogId=10002&catalogIdentifier=Jegs_Direct&categoryId=26691&parentCategoryId=10241

MachinistOne
07-21-2006, 10:33 PM
Don't put us all in the same catagory...if all he needed was a hole drilled I would have charged him $5 if that, and tell him to come back if he needs anything major....

James Montigny
07-21-2006, 11:00 PM
I could not find an adjustable timing set for a 93 LT1
They make them for SBCs and 95+ LT1s, but not for 93s.
They do make them for 94 LT1s, but they are for cast-iron headed LT1s.
(The cast iron headed LT1s got the new cam and timing set design a year early)
I probably could have made it work even though it was the wrong part,
but I opted to use the bushings.

I bought a Lunati set (which appears to be a rebranded GM set)
and just drilled a hole. It didn't cost me anything extra to drill the
hole, the same shop doing the install did it for me.

jerminator96
07-22-2006, 03:12 PM
Don't put us all in the same catagory...if all he needed was a hole drilled I would have charged him $5 if that, and tell him to come back if he needs anything major....

I wish I lived closer to you then. Of course, the hole I needed to be drilled was a rollpin in the shift rail of my T-56 (it got kind of "welded" in there:mad: ). Anyway, $100+ to drill it out, or $20 to cut the $25 rail....tough choice.