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KingDom · Post by **KingDom** » Wed Sep 20, 2006 3:11 am

I have removed the aluminium plugs from my 2.0 litre crankshaft and put a tap through to make a 7mm thread. (I broke 3 taps doing this process!).
I now require 7 mm grub screws.
Does anyone know where I can get these? Preferably in Australia.
I could use bolts sawed off after tightend in position but prefer socket headed grub screws for ease of removal.

Thanks,
Dom

Mats · Post by **Mats** » Wed Sep 20, 2006 8:06 am

M7 grub screws? And I thought it was difficult enough to find regular M7 screws...

sh0rtlife · Post by **sh0rtlife** » Wed Sep 20, 2006 8:28 am

try a local bolt shop..and id be suprised if they couldnt order it for you

Barry · Post by **Barry** » Wed Sep 20, 2006 10:16 am

I had a terrible time finding M7 grubbs....

Took a masonary drill bit,ground the tungsten tip to 6.8mm wide,drilled the crank and then tapped it m8...

V6`s I fit m14 pipe plugs...

x-rad · Post by **x-rad** » Wed Sep 20, 2006 4:57 pm

I got 8mm plugs, seeled them, and peened them in with a hardened chisel.

Mats · Post by **Mats** » Wed Sep 20, 2006 11:25 pm

One thing I don't get in this crank business...

Why is it so fricken hard to drill the holes? The depth of the hardened bit should not be very large?

TS_turbo · Post by **TS_turbo** » Fri Sep 22, 2006 6:07 am

those cranks are forged hardened steel..very dificult to dril or tap

.. i broke 3 taps and 2 dril bits in single nord crank

second dril bit broke deep.. then i sealed oil holes of 2nd main jouurnal and driled direct oil way trought main oil galery to 2 and 4 main bearings

KingDom · Post by **KingDom** » Fri Sep 22, 2006 4:36 pm

looks like I will be inserting 7 mm bolts tightend into position then saw off flush to the crank web.

TS_TURBO is it necessary to plug the main crank journals of 2 & 4 after drilling in the block for additional oil supply to the bearings 2 & 4

TS_turbo · Post by **TS_turbo** » Sun Sep 24, 2006 7:00 am

no its no need, i just blocked oil feed to 2 and 4 main bearing when i broke drill bits inside

Barry · Post by **Barry** » Sun Sep 24, 2006 8:25 am

If you guys use a masonary drill bit with the tungsten tip,it will drill the nitrided crank like mild steel.Slowish speed and gentle pressure.
Like a hot knife through butter..

I dont know why you guys battle with this.

MR2 Zig · Post by **MR2 Zig** » Sun Sep 24, 2006 10:54 am

As Barry said, or, you can go to the local industrial supply house and get an appropriatly sized carbide bit. Also, don't drill your holes using the regular drill chart that uses 75% thread engagement, use a drill size that has 60% engagement and you'll not be breaking your taps.

As your steel gets harder/tougher you will need to slow your drill speed (rpm). Alignment is critical as the carbide bits, while very hard, are brittle and won't take a side load.

HTH,
Scott

7 mm grub screws

7mm grub screw