any tips on boring a con rod on the mill table?

[Servicar rider]

Just google Storm-Vulcan U-30 rod aligner and you'll see pictures of what I use. After you bore a couple of Harley rods you'll figure out why people just bend the rods to straighten them. Most of them are pretty good and don't need much if any correction. AAMCO and KO LEE made checkers too but they are not as accurate as the Storm Vulcan. You'll find boring the wrist pin holes is a pita? But good luck.
I like that Berco machine, I've seen a couple older ones that were similar but another brand.

 

[john.k]

I have a manual rod boring setup (as an ornament) and included with the bits and pieces was set of internally tapered mandrels ,split one side ...these are the mandrels to test rod alignment.....there is a taper peg to suit mandrel internal taper ,mounted in a cast iron plate about 6"wide and 18" high.....you mount the rod big end using the correct expanding mandrel so its rigid,and then use the SeaLion to determine rod bend ,twist ,or whatever.............then by use of the rod bending vise supplied with the set ,you correct the rod ,and retest.........both Harley and Indian have details in the shop manual on rod alignment using a bending bar .

 

[1940indianchief]

Here is a shot of my AB320
Rod mounts vertical (no sag due to gravity) \
Spindle mounts solid boring bars (40 taper)
Expanding mandrel mounts to slide that sets the rod length. Different mandrels cover a size range.
Can hold the rod either way and bore either the big end or the small end.
Bed provides the long power feed

2and photo taken after adding DRO to long feed to control facing cuts (White metal rod applications)

Looks like there is one on bid spotter.....

Berco Model AB-320 Rod Boring Machine, s/n 662B, Minimum Boring Diameter 19/32”, Maximum Boring D

Lot 215 at CENTER DIESEL & MACHINE from Thompson Auctioneers.

www.bidspotter.com

Cheers Ross

Here is a shot of my AB320
Rod mounts vertical (no sag due to gravity) \
Spindle mounts solid boring bars (40 taper)
Expanding mandrel mounts to slide that sets the rod length. Different mandrels cover a size range.
Can hold the rod either way and bore either the big end or the small end.
Bed provides the long power feed

2and photo taken after adding DRO to long feed to control facing cuts (White metal rod applications)

Looks like there is one on bid spotter.....

Berco Model AB-320 Rod Boring Machine, s/n 662B, Minimum Boring Diameter 19/32”, Maximum Boring D

Lot 215 at CENTER DIESEL & MACHINE from Thompson Auctioneers.

www.bidspotter.com

Cheers Ross

Wow! That Berco machine is a Beauty! and what an awesome machine shop you have. Thanks for the bidspotter link, I will be looking into it.

 

[1940indianchief]

Just google Storm-Vulcan U-30 rod aligner and you'll see pictures of what I use. After you bore a couple of Harley rods you'll figure out why people just bend the rods to straighten them. Most of them are pretty good and don't need much if any correction. AAMCO and KO LEE made checkers too but they are not as accurate as the Storm Vulcan. You'll find boring the wrist pin holes is a pita? But good luck.
I like that Berco machine, I've seen a couple older ones that were similar but another brand.

Thanks for your input and everyone else who replied. I appreciate and read everyone's input.

 

[just Dave]

I have the S&S checking pin, and the Sunnen hone and dozens of mandrels. I'm just trying to re invent the wheel, if I can make both bores perfectly parallel, then I won't need to bend the rod. Any chance you could post a pic of your storm vulcan rod alignment machine? Thanks

The rod is already bent, if you don’t straighten it before machining it the force associated will be off center.
Do you see the problem?

 

[AlfaGTA]

There are OEM rods that are made off center by design
If the bores are parallel so are the forces.
Think the big issue is to be sure the rod small end is not “leaning “ on one side of the piston. (clearance)
Think the need to straighten comes down to the amount the rod is bent.

Cheers Ross

 

[PackardV8]

Love the Tobin-Arp rod boring machine! We get one in for rebuild/resale every once in a while. They're the most flexible-yet-precise manual machine I've ever operated. We've bored rods, big end and small end, as well as piston pin bores and it holds tenths with no problem.

jack vines