Jerry, Often the problem in boring operations is the chip. Your tool needs to be sharp and usually have at least a very small radius on the cutting tip. The radius helps to blend the machining line and the sharp is obvious. The tool also needs to have enough side clearance to allow the chip to get by or be broken off. The last is often hard in small bores which is why lots of people ream the holes!
Bill Jepson
-----Original Message-----
From: Jerry Hey <jerryhey@earthlink.net>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Thu, 30 Jun 2005 12:54:59 -0500
Subject: [FlyRotary] Re: Machining help needed
On Thursday, June 30, 2005, at 11:36 AM, Russell Duffy wrote:
> I have to disagree with your observation. The boring
> tool, by itself will not yield a surface appropriate for
> seating the injector o-ring (and easy removal for service).
>
>
> Hi Dale,
>
> I have to disagree, with your disagreement :-) I used a boring bar, > in a mill to open up the stock fuel rail holes for my MSD injectors. > I've also bored holes in a cast aluminum intake for the bottom end of > the injectors. All holes are sealing just dandy, though I was pretty > paranoid about the fuel rail holes. I must have checked those 100 > times to make sure they weren't leaking, but now I hardly give them a > thought.
>
> Cheers,
> Rusty
In this case it depends on the operator. Using the boring bar in the lathe and being very careful on the set up, I could not achieve the polished smooth finish I was hoping for. I am self taught in machining and sometimes come up short. I don't mind having a reamer ground for the purpose. Jerry
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