KR Wilson Main Bearing Reamer

[Smitty]

Anyone know where I can have a Wilson main bearing reamer machined to under-size?
S

[Joe K]

Originally Posted by Smitty

Anyone know where I can have a Wilson main bearing reamer machined to under-size?
S

Yes - original replacement Model A Cranks (which the reamer is designed for) can be pricey

Any machine shop that does cylindrical grinding should be able to do the job.

Even a shop with a tool-post grinder if the machinist doesn't mind crapping up his lathe.

But - maybe the task better served by beg, borrowing or stealing a kwik-way line bore? http://www.fordgarage.com/pages/kwikwayparts.htm

There are other brands.

Or bring it to a rebuilder for just that part of the work?

Joe K

[larrys40]

Originally Posted by Smitty

Anyone know where I can have a Wilson main bearing reamer machined to under-size?
S

To answer question directly I do NOT know if anyone who would be able to undersized and sharpen your reamer . I’m a Krw junkie and in my opinion if you are cutting Babbitt and line boring you need an a adjustable reamer and mic to take it to the required precise size. Cranks vary and of course after turning to undersize today and their variance one size fits all isn’t practical.

I use a lemco bar, there are many others out there. You might contact arylyn Bieber on the forum here as I know he uses a modified Kr Wilson setup at Hansen’s garagecout in San Diego. Just spoke to him yesterday and Arlyn is a friend and super occomodating Model A friend. Guys like Herm Konke are also resources that know this stuff in their sleep.

Larry Shepard

[Joe K]

If you're in Massachusetts, possibly the BEST place to bring a Model A engine is J&M

He does work at a VERY high level - like "blueprint" engine level. But he'll work with you.

https://www.jandm-machine.com/lineBoring.html

There are others.

Joe K

[Smitty]

I am familiar with J&M and others in the area. The idea here is to do my motors in-house.
Way too expensive to farm motors out for rebuilding, especially considering the life span they have.
I have been building my own motors for over 50 years and have all the needed equipment here with the exception of good line-bore setup.
May bite the bullet and drop a Merc. flathead in her.
S

[redmodelt]

Sponsored Links (Register now to hide all advertisements)

Check around for an outfit that does re sharping of tooling. The guys that I have been around that do T, A etc babbitting work have reams done up to do the standard under bore sizes so there must be places to have it done. Example they will have Std, .010, .020 etc reams ready to go. I understand the variances in grinds, you still have to fit the crank (or rods) after boring and reaming.

[John]

As you may know, the original KRW setup used a boring frame with fixed cutters to bore to the diameter needed to use the KRW reamer. This was a good practice as crankshafts were cheap and plentiful and one only machined the bearings to the original specifications. Later with reground crankshafts, many of the old time engine rebuilders altered the KRW boring frame so that the cutters were adjustable. The adjustable cutter principle is used in the Kwik Way and Ammco bars and the Tobin Arp tooling for line boring. The reason for the adjustable cutters was that any main bearing could be bored to match any crankshaft journal size and no reamers were needed.
I have seen Model A crankshafts where the center main was ground to a different diameter than the front and rear journals. So even though I have several of the reamers for the main bearings myself, get a line boring setup with adjustable cutters. This type of setup can also be used for boring the mains when installing insert bearings.

[redmodelt]

Sure you can do it that way but you really have to pay attention to the radius and angles on the cutter. If the the cutters are ground wrong, you will end up with ridges, that's why it was a two step process (after poring and peening), cut the boar then ream to get a good finish.

[Smitty]

From what I am hearing it sounds as though the KRW Combo machine rpm is low and feed rate is high causing the bar to make a rather rough cut.. Which would be why the reamer was used to finish..
Is there another way to shape the tool bit to give a smooth cut?
S

[BRENT in 10-uh-C]

Several options in this regard.

There are tool grinding shops that can sharpen reamers however it does alter the finish size. For someone doing their own crank work, the crankshaft can be welded and then be ground to the new size of the reamer.

If someone is still wanting to use the combo machine, as mentioned by John, just machine a boring bar to fit the plate that uses adjustable cutters. You just need to be creative on driving the bar.

Another option for a home hobbyist that doesn't want the expense of a Kwik-Way LBM with the Model-A/B set-up fixtures is to purchase one of Gene French's line boring set-ups.

[redmodelt]

For what it is worth, the KRW feed threads are 36TPI. It could be ruff if the radius is wrong and you could end up cutting threads in the babbitt. Think of it like mowing a lawn, if you overlap the last pass you pickup the grass the wheel ran over.

[Kohnke Rebabbitting]

Originally Posted by Smitty

From what I am hearing it sounds as though the KRW Combo machine rpm is low and feed rate is high causing the bar to make a rather rough cut.. Which would be why the reamer was used to finish..
Is there another way to shape the tool bit to give a smooth cut?
S

The main reason was to make it so anybody could do it, Wilson tried to make it fool proof. The adjustable cutters were made first, that didn't work out, as not all mechanics could get all three mains the same size. So they went to a larger bar, and fixed cutters.

If anybody is wanting to make a cutter for boring babbitt, the bar you are going to use, you have to know how far the cutter, or bar moves in one revolution. That can be done with a dial indicator.

Don't use round nose cutters. So, say the bar moves .010, the cutter tip has to be that, and two to .010 wider. If you give the back of the cutter to much relief, it will catch shaving there and groove the bearing surface. There is a lot to it.

Herm.

[Joe K]

It technically IS possible to hand scrape to a size. You will need a "proofing mandrel" of the EXACT same size as your crank - or use the crank itself. Fine Woodworking Magazine back in the day had a nice article by Bob Johnson about pouring and scraping bearing - there are other articles.

"Repouring babbitt bearings -a low tech way to rescue old machines "
by Bob Johnson appeared in Fine Woodworking Magazine issue # 38 Jan/Feb 1983.

The Critchley piloted reamers came to mind too. Electric motor re-builders use these for the two brass sleeves used in sleeve bearing motors. There is the expandable reamer AND an extension and pilot which one uses in the "other" bearing hole.

Critchley is local to me (Portsmouth, NH) and one imagines they're not averse to "custom work" of making an extended pilot. Or have one made local. The critchley type reamers have been reproduced by the Chinese (minus pilots) and are available at Harbor Freight for relatively small money and reasonable quality.



But all of these methods border on "hand work." While you're not averse to hand work (it seems) one should want to use the best means available to them. Which includes in no small part attention to "setup" which a hand method is challenged to present. And three co-linear bearings are their own challenge.

Joe K

[redmodelt]

You would still need the frame to keep all the bearings bored in alignment, straight and the correct distance to the cam. The cutter would have to slide along the shaft, passing thru each bearing as it was cut. That would be a long shaft that could be subject to flex depending on it's diameter. You could not just use a piloted ream, it has to be index to the center of the cam and does not mean that when the bearings were pored would be centered anyway to used. Most of the boring setups for a 3 main block would use 3 cutters ruff boring and 3 fluted sections for reaming so you are doing all 3 at the same time.

[sphooch]

Originally Posted by larrys40

To answer question directly I do NOT know if anyone who would be able to undersized and sharpen your reamer . I’m a Krw junkie and in my opinion if you are cutting Babbitt and line boring you need an a adjustable reamer and mic to take it to the required precise size. Cranks vary and of course after turning to undersize today and their variance one size fits all isn’t practical.

I use a lemco bar, there are many others out there. You might contact arylyn Bieber on the forum here as I know he uses a modified Kr Wilson setup at Hansen’s garagecout in San Diego. Just spoke to him yesterday and Arlyn is a friend and super occomodating Model A friend. Guys like Herm Konke are also resources that know this stuff in their sleep.

Larry Shepard

Hi, do you collect KR WILSON tools, if so I have some laying around for years in my garage. let me know I can post a pic.

[BRENT in 10-uh-C]

Originally Posted by sphooch

Hi, do you collect KR WILSON tools, if so I have some laying around for years in my garage. let me know I can post a pic.

Like Larry, many of us are 'Tool Whores' and love to buy more tools. Post pics of what you have!!