Has anyone performed the 430 oil mod recently? I drilled out the oil passage to 5/8” using a 6” bit. But the 12” bit I bought won’t remove any material. If you have used a 12” bit that worked, where did you buy it? TA does not show the drill bits on their website anymore. Looking for a bit that will work and not waste money trying different ones. Thanks
Drill bits are for drilling holes........ What you want is a counter bore.. They are used for enlargement of a existing hole. like this.=====5-8-3-flute-solid-cap-screw-counterbore-1 Drill bits WILL walk its own path....... CBs stay in the original path.....
I think reamers would also work (granted this is an expensive set as an example but you could just buy the couple individual sizes you'd need): https://www.mcmaster.com/product/3008A8 I used them at my old job to enlarge existing holes a lot!
My machinist uncle made drill bits for me with the tip narrowed down to guide the bit perfectly concentric through the original hole so that it does not wander off center. Also do not use oil when drilling cast iron. Oil combined with the heat generated by the drill bit will harden the cast iron and make it extremely hard to drill. Drill cast iron slowly and with no oil.
The way I am reading it, there is too much shank. The drilled material is not transfering back towards the drill and out of hole.
Possibly, if so and the bit is actually sharp then it's a matter of technique. I've done the same job a few times with maybe five inches of body and the rest shank (my homemade bit is something like a six inch drill welded to 1/2" round stock). It's a matter of drilling & making some progress, then pulling the bit completely for cleanout, and just keep repeating. Devon
I’m sure it’s the drill bit. The 6” dewalt bit I used bored out the block easily. Unfortunately, dewalt doesn’t make a 12”x 5/8” drill bit. The bit I bought has 8” of body so clearing out the material shouldn’t be an issue, if it would cut. Thanks to Devon, I came up with a solution. I had thought about welding some 1/2” round stock to the end of the drill bit which worked, but I don’t have a way to align the two ends perfectly to weld. It then hit me, sleeve it. I can use some bushing stock, 5/8” OD 1/2” ID, insert then weld both ends. That should give me perfect alignment without using some jig or a lathe, which I don’t have. Thanks.
