Valve Guide drill bit source needed

[john walker's workshop]

I used to get them from Baum tools. Jerry Woods Had them for a while IIRC. Getting a batch made from a tooling outfit isn't cheap. Any idea who still stocks them?
Pilot end is 9mm to fit the guide bore.
Drill bit OD is 11.80mm/.464".
I'm down to my last one.

[1982911SCTarga]

Could you make a few step drills using your metal lathe, a toolpost grinder (or even a Dremel mounted to the toolpost) and the correct-size drill bits (.464" O.D.)?

Nix

[Missed Approach]

Apologies John- not much data out there. Using the Wayback Machine, I was able to find the old listing from the Baum Tools online catalog for May of 2005. Below is the main image clip. The pop-out was not available, but it references Tool #87 as well. Hopefully, this helps in the search...

Link: https://web.archive.org/web/20050507123638/http://tools.baumtools.com/index.jsp?menu=por&newIndex=3&index=11&make=por&model=&part_number=&primary_section=&secondary_section=&tool_use=

[john walker's workshop]

Baum said they didn't have them, but I'll try calling with the number 86B.

[Charles Freeborn]

Looks like a modified twist drill bit. A good machinist with a grinding attachment on a lathe and the proper sized collet could knock out a batch reasonably quickly. Mc Master will have the core bit.

[Trackrash]

Originally Posted by 1982911SCTarga

Could you make a few step drills using your metal lathe, a toolpost grinder (or even a Dremel mounted to the toolpost) and the correct-size drill bits (.464" O.D.)?

Nix

I have done this. Takes time, fiddling, and knowledgeable use of a lathe with a tool post grinder then finished with a drimel, but is do-able for a DIYer.

[john walker's workshop]

Don't have a tool post grinder. Rather buy several. Already priced getting some made and it's out of hand. Must be some out there for sale.

[Jeff Alton]

John,

I will poke around as we would buy a bunch as well.

[otto_kretschmer]

can you go to .492 OD?

https://www.cylinderheadsupply.com/dcmkwikway.html

item 7211 is sorta kinda close

all you're doing is drilling out the old guide and leaving a shoulder so you can pound it out?

[otto_kretschmer]

maybe another

https://www.mcmaster.com/29525A56/

I don't have the stem diameter so I looked at my BMW motorcycle book and the airheads use 8mm stems.

[jlex]

[fanaudical]

John - I suspect there are many Seattle-area shops making custom machining / cutting tools for the local aerospace industry. I did a quick Google search and came up with this one:

Cutting Tool Control, Inc

Cutting Tool Control, Inc

Cutting Tool Control, Inc

I'm sure there are others. If you know somebody local in the machine-shop business, they may have a favorite tool grinding service they use.

[ab1752]

Originally Posted by Jeff Alton

John,

I will poke around as we would buy a bunch as well.

Hey Jeff you may want to reach out to Modern Engineering on River Road, they may be able to help.

Cheers,

Andrew

[john walker's workshop]

Cutting tool control did the last batch, but new people in there now that are less than cooperative.
Swift tool wants $149 for one and $84 each for six. Gotta be a better deal.

[john walker's workshop]

Originally Posted by otto_kretschmer

can you go to .492 OD?

https://www.cylinderheadsupply.com/dcmkwikway.html

item 7211 is sorta kinda close

all you're doing is drilling out the old guide and leaving a shoulder so you can pound it out?

If the OD is much larger, the remaining shell is thinner and I fear it could break from the driven part and remain in the bore. The size I have now works fine.

[john walker's workshop]

They were ready made and available several years ago, just for drilling out 911 guides, so there should be a source from the past that provided them.

[Jeff Alton]

Originally Posted by ab1752

Hey Jeff you may want to reach out to Modern Engineering on River Road, they may be able to help.

Cheers,

Andrew

Thanks!

[Essexmetal]

Since this has the same layout as a drill piloted counter bore, what stops you from sharpening the current ones you have?

The drill point is pretty standard and the counter bore portion can be sharpened on a tool grinder. Same operation as tip sharpening an endmill.

[otto_kretschmer]

Originally Posted by john walker's workshop

If the OD is much larger, the remaining shell is thinner and I fear it could break from the driven part and remain in the bore. The size I have now works fine.

the one I found on McMaster Carr has a big ID of .469 and a small ID of .313 (8 mm) and they want $59

this should work and I doubt you will beat the price

[john walker's workshop]

But I need a 9mm pilot. 8mm works for a 993. I have those.