What's new
What's new

Portable crankshaft grinder drawing

nick c

Plastic
Joined
Jan 28, 2008
Location
Ocala Fl.
I saw a Winona in the bolk crankshaft grinder that can be attach to the underside of a truck engine or to a lathe and turn down the rods and the main journals. I saw it on the forum for model A Fords called the Fordbarn. I could build one if I had a drawing. Are ther any drawings out there?
thanks nick c
 
I know someone who has a turning tool for use on crank journals on a lathe. It has a long handle (torque arm) that rides the front edge of a way or chip pan and IIRC some sort of V-block arrangement to get roundness back. No control of crank stroke so the centerline winds up wherever it winds up. Probably same vintage. Does that sound like the device you're thinking of? No drawings, but it could be sketched up.
 
I watched one of these grinders in operation when I was about 8 years old (a couple of hundred years ago) in my dad's truck shop.

6 cylinder International "Metro" had a spun rod bearing. The local auto machine shop had a portable, brought it to my dad's shop. Set the Metro on jackstands for enough working room, pulled the oil pan, pulled the head and the piston/rod in question. The grinder clamped over the upper side of the journal, and the grinding wheel was below the journal. Crank was rotated with the engine starter. Grinding commenced!

I scooted under the truck and watched, the grinder was going up and down on the rod journal, a real arm breaker if you got in the wrong place.

Sort of a cheap short term fix. I am sure the rest of the bearings were near failure due to all the spun bearing material in the oil system, not to mention the grinding residue left over from the "fix". But this was way back in the dirt poor South, folks could barely afford a shade tree quick fix, let alone a full engine rebuild.
 
First off check ebay as I have seen the grinders for sale on ocasion. Second you can only do rod journals in the vehicle ,no mains. A friend of mine had one throw in one of his semi-tractors turned in the engine in the last year or so. They hang down quite aways so if there is a crose member in the way you are SOL. Was a good deal in the 30-50s era.
 
I built one to repair a hay-baler crankshaft---3 1/2" diam crankpin, and 28" of stroke.

It worked. I could take some photos..don't know if I kept the sketches I worked from.

I started by going to a little old engine machine shop, and asking about them They had one, at the bottom of a box of junk, and I looked it over. You may be able to find one to look at closer than you think. They used to be common
 
There's virtually no hope of finding drawings for one of those grinders. It would be an reverse engineering job of dubious merit. I found one for sale inside a minute with a simple web search. If you need one they're available. Van Norman built them too.

Last time I watched one used was in 1958 and all the grit flying was astonishing.
 

Attachments

  • Winowa In-The-Blok.jpg
    Winowa In-The-Blok.jpg
    11.1 KB · Views: 2,903
If I saw something on one website, why go to another and ask about it?

I would like to understand the logic behind the behavior.

And why would a Prius owner go to a Smart Car site and ask how to get a key made? I saw that behavior, also.

Just wondering...
 
Of ????? merit MOST times...

Not every job has to be perfect..

I know of an OLD JD 690 chain drive excavator , No letters... worth squat.. has 1 rod journal .015 out of round.. Every other year, it gets a new rod bearing, Loose as a goose engine (diesel ) with known rod bearing issues for that model engine..

Owner does not rev it up past 70% or so... been running for 10 years...

An inframe crank grind would get it up to 90% or so

Grit is easily flushed with a solvent spray gun... Gravity works for the sluicebox... lots of clearance under an excavator engine oil pan.

Perfect solution NO, but bush Alaska is an imperfect world..

50's style rebuilds... (new rings and a valve job) sucked.. But many an engine was limped along a few more years...

When the machine is worth 2x more as scrap steel, it's a machine that is worthy of only a cheap ass repair..

Not a classic collectable, more of a 1975 4 door Chevy with unibody rusted out.. Smog equipped ..
 
I spent 20 years in the engine rebuilding shops and look for related antique tooling. I owned a Winona "In the Block" grinder for a time while I was still in the trade (late 80s) and here's my story---
One day the City garage mechanic was in the shop asking if anyone still did that type job, seems they made a deal to trade in a running garbage truck on a new one and a rod started knocking. They had to drive it to Minneapolis to trade it in and pick up the new one. He made an offer I couldn't refuse if I could do it so--- what the heck? Give it a try!
My Winona grinder came with a roller drive unit meant to sit under a rear wheel of a car to turn driveline and it had a small pulley on the end of one roller. NO way could I set a garbage truck on it! So, I propped the drive unit over engine with V belt to the front pulley, I'm guessing it was maybe 10-12 rpm on the crankshaft. You CAN'T use the starter, it's too fast and would burn out with the long cranking times needed. Engine was a 3208 CAT V-8! Diameter of rod journal was a little bigger than what grinder was made for but it fit & worked.
They only had one head off the engine (injectors removed so no compression) which meant I had to regrind 1/2 of one rod journal with the other connecting rod IN place and moving with crank. It was about .007" out of round as I remember but not burned.
Plugged the oil hole, hung the grinder, got the engine turning, and started grinding. Face of stone is dressed with a diamond and wheel is smaller diameter than width of journal so you have to sweep back and forth to get full width as you continue to advance feed. There are adjustable stops to control sweep width. It starts to grind the high spots and when it seemed like it was pretty well hitting all the way around I stopped to check progress. It measured a near perfect .010" undersize with a fingerprint sized spot that was not quite cleaned up, on top of journal, at top of stroke. It would have to go to .020" under for next available bearing and grinder was already hot! SO----
We polished it up with a loop of emery strip, cleaned things up as clean as possible, and put it together with a reconditioned con rod and a .010" under bearing shell. It was driven 200+ miles to Minneapolis and was running fine with acceptable oil pressure. Trade in was accepted and no one knows what ever became of it! I got 8 times $$ what I paid for the grinder--- should have kept it but traded it off years ago.
The Winona grinder is a very well made unit. There were different size hook assemblies for different diameter ranges. They have tiny roller bearings to guide it. If you buy one---- Be sure to get whatever stones are available. They are mostly white grit and are integral to their 10"-12" long shafts. I don't know how you would come up with substitutes.
You might also find a drive unit, either the motorized gear reduction roller unit for rear wheel like I had, or one that goes across fenders and drives front pulley with a belt.
I also STILL have a Sawyer-Weber tool for use in a slow turning lathe. It uses different width cutter bits opposite a V- block shaped hook to scrape the journal round. Never used it but seems like a well made device.
I know SUNNEN also made one of these portable grinding units but it swept across journal the other way so wheel had to be dressed to exact
diameter I think. Wheel was cupped I think and it ground with the face so the trick was to manipulate feed to NOT get barrel or hour-glass shaped journal.
 
Being a "po' boy" in the fifties, I rented one of them to refurbish a crank throw on my '51 Hudson Hornet.

Pain in the butt but it worked. Head off, (had to R&R the piston and mangled con-rod + compression release) grill and radiator out and a friend doing his best hand cranking the engine with a "cheater bar", extention and socket on the front pulley nut, shouted instructions from under the car. That's where I learned that removing metal with a precision grinder is a fussy, frustrating job. At least I got to do it laying down.:rolleyes5: Just filed off some bumps around the gouges on the bottom of the barrel.

Bought my first 2" mikes for that job, "undersized" insert chart in hand.

I don't recall taking any precautions regarding grinding dust, just wiped 'er down afterwards, wha'did I know?

Had one of those "advanced", toilet paper roll filters, wasn't worried about a little grit.

Drove it for a few months, no problems, though my driving style did mature for the occasion. I sold it still working well, (no noticable knocking) which was a surprise and great relief to me. Replaced it with a black '50 Chevy Sports coupe, white top, dual pipes, lowered and red fingernail polish painted inside the 2 side interior light covers, mood lighting....... pulled the lowering blocks for a "rake", cool man....

Bob
 
I owned a Sunnen from '72 until the late '80s and only used it a few times. I didn't give much for it and junked it when I cleaned the shop one time. I couldn't get stones for it through my local sources at the time but I got quite a few with it. It had a motorized roller to turn a tire and a motorized/gear reduction attached to a flexible shaft that engaged the ring gear on a flywheel. It did what it was designed to do but I really sweat bullets when I used it! A crank could have been easily ruined.

Rick
 








 
Back
Top