i have a 9/16 drill bit to drill out the oil passage on a buick block. also i had a machinist friend make a cutter with a 3/8 guide so you can get the hole stated correctly. it cant wander because you can get the hole about half way following the original hole. this really worked great and i didnt worry about the bit wandering off and putting a hole in my original block. i have no use for it now so if someone wants it i'll do $50 shipped anywhere in the 48 states.
The pilot bit is a good idea for this application, but I wonder if he should be considering talking to a lawyer about patenting this. Your machinist friend may be sorry he didn't down the road. A piloted drill bit is not a new idea, but for this application it may be. I used to work with a guy that that years ago looked at Harley's Big Twin 5speed transmission and figured out a way to add an additional (overdrive) gear. As far as I know he didn't patent the idea and of course everyone copied it. Even Harley finally added a sixth gear to their Big Twin product line. At the time Bert opened up his own successful motorcycle transmission business, but the money he could have made off of royalties alone.... .....just sayin'.
Like that idea quite a bit, actually! I have two blocks I'd like to 'borrow' this for (I'll buy it, but then would likely be selling it, like this) - count me inline if it makes it to me.
well ,no patent or royalties. lol i'm sure if you are in the tooling field something like this isnt unusual.
i think he just modified a commercially available tool. it has markings on it. i will post them tomorrow.
Not sure patenting it is really necessary in this case but would your machinist friend be interested in making some of the pilots? I'd buy one. Maybe make them in 5/8" too. I'm not sure but is enlargement to 5/8" not possible or just not deemed necessary on the 350?
heres whats stamped on the tool. putnam tool co. 3/8 x 9/16 cs24 m-2 dano - it just looked really scary to go to 5/8 . ta says they do it but to me it wasnt worth the risk on my original 350 block. i will reach out to my friend and see if he can get more or you guys can try the internet?
Thanks! I searched that # & didn't come up w/anything but probably could find it in a tooling catalog. I coukd probably even do the mod myself but was thinking if it was something he modified maybe he'd want to set up and make a bunch to sell on here. Doubt anyone is getting rich off it but... I agree on the orig. block. I have the 2 orig. 350's for my GS's which I'm planning on m/l stock builds but would go 9/16" on them & then 5/8" on the subsequent higher HP builds so if your friend wants to make them, I'd take one of each.
Back in the day, they told me 9/16" was as big as you wanted to go a 455 block with the small passage. It was still much better than the old passage. On my original 71 350, I drilled mine from 7/16" to 1/2" and it worried me. You might get 9/16" if you are really lucky but I'd bet going 5/8" on a 350 will be a very risky event. TA sells a 1/2" pickup for the 350. If you try, please document it for future readers to duplicate.
Guys, I don't think anything over 9/16" is needed. I have all the o/p I want at 9/16" up to 7k+ using 5/8" pickup. Don't re-invent the wheel....