jdelo

I'm having one hell of a time drilling and removing a Stainless steel stud that broke in one of the emi headers.
I used colbalt drill bits. I tried to drill a pilot hole with a bit size of 1/8". Nothing, the bit didn't put a dent in it.
Does anybody have any other ideas with out having to remove the header?

Thanks
Jdelo

AKA TSUNAMI

maverick1

I've got the cure. Stainless is a different beast when it comes to drilling it.

Start with a drimmel tool - grind a small "notch" in the surface for the drill bit to catch. THEN get your drill bit and a variable speed drill - run a VERY LOW RPMS - otherwise you will just immediately cook/dull your bit. Once the bit starts cutting it will cut like butter! Send me a PM after you discover that this DOES WORK!
MAV

jdelo

MAVERK1,

Thanks, I will let you know if it works.

mcollinstn

Be CAREFUL. If you drill goes offcenter, it will "walk" into the aluminum which is much softer and easier to cut than the stainless.

The only way to be SURE you are gonna get good results is to remove it and set it up on a mill to cut it out with and endmill. Go bigger and bigger till you are at the thread minor diameter - then the stainless threads will come out in a big spiral slinky.

Big Boys Toys

Stainless will drill with conventional sharp drills.
The secret is to start of with a perfectly centered hole. If you do not start in the center everything goes sour from there on.
If you have allready screwed up the hole the dremel tool will allow you to clean out your mistake and start over.
Postitoning yourself with the headers in the boat is also going to be a difficult situation. Get a couple of moving blankets and get yourself set up so you can apply some pressure and keep the hole straight. Have some else standing by to do the oiling while your drilling.
You also need to keep the rpms down otherwise you work harden the broken part by heating up the tip of the drill bit.
Keep the rpms down and use some cutting oil to lubricate the drill.
Take your time once that the small hole is in you can step drill it open a sixteenth at a time.
Good Luck
Brian

Dave M

My friend had the same problem twice this past season. He removed the manifold and took it to a machine shop. He got it put back together only to have it happen again. He called EMI on this and they are going to make good on it. I think they are sending him new manifolds. EMI is aware of the problem

blue thunder

Drilling should only be a last resort. Rarely do I need to resort to that. The old punch and hammer trick works neverly every time. That is, you can back the bolt out by tapping on the outer circumfrence of the bolt with the punch/hammer. Don't be shy about how hard you hit it. Just make sure you stay on the bolt and not get into the threads. Good Luck.

BT

jdelo

Everyone,

thanks for the recommendations. Dave M, this is the thrid time it's happened to me. the two times before I was tearing the motor down so I was able to use a drill press.
I emailed EMI their response was to take the manifold off and oh bye the way email your address so we can send new gaskets and studs. I"m very interested as to what EMI told your friend, regarding this problem.