crankshaft shims

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seattle##gs

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I have .029 end float. Old Britts used to have a kit with a few shims of different thicknesses. AN has .003 shims at about $4.00 apiece. That's about $24 for 6 shims. And waiting for them to arrive. .029 seems excessive. I know there is opinions about shimming or not to shim. I'll try shimming. anybody know of a source here in the USA? Or have extras to sell?
 
My 850 had 0.031" with the original cracked crankshaft and 0.029" with the replacement, because I was there (engine stripped) and could machine my own stainless steel shims I did so.
Does it matter, probably not but if you can, why not.

I reduced it to around 0.012".
All my spares were sent to a member in Europe for free, you probably read about here. 😄

s7.jpg
 
The AN shims are not case shims, they go under the crankshaft inner of the bearing.
Don't use them. (I bought those only to fine that which led to making my own in the exact thickness needed (one per case bearing)

I might add, when you grab the end of the crankshaft, 0.029" feels more like 0.29"
Would I strip an engine to do it, no.
If the engine is apart and you have the skills and means to do it, I say yes.

I did make sure to add a weight until the engine case was cold to avoid creep from the shim.

s55.jpg
s44.jpg


There might an online option to have custom shims cut. You just enter the size.
 
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I installed the bearings and crank, bolted it up and measured the end float. Didn't even have the cam in. Now's the time to adjust end float if I can find the shims. I've had shims made for Triumph push rods and they are really expensive...$200 for 60 of them. Someone must have a set to sell.
 
seattle##gs said:
I installed the bearings and crank, bolted it up and measured the end float. Didn't even have the cam in. Now's the time to adjust end float if I can find the shims. I've had shims made for Triumph push rods and they are really expensive...$200 for 60 of them. Someone must have a set to sell.
Click to expand...
CanukNortonNut said:
Macmaster Carr!

www.mcmaster.com

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.
www.mcmaster.com www.mcmaster.com
Click to expand...
McMaster Carr has them.

2" Ring Shims. #98126A366... .006 others available...
 
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Another thread mentions these in the direct link below or is it the same part as above.

www.mcmaster.com

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.
www.mcmaster.com www.mcmaster.com
 
These are the dimensions I used, the 70mm OD sits just inside the fillet in the base of the bearing bore of the engine case.
The ID if smaller would not matter, I did it that size to suit the bearing race.

crankshaft shims
 
seattle##gs said:
I have .029 end float. Old Britts used to have a kit with a few shims of different thicknesses. AN has .003 shims at about $4.00 apiece. That's about $24 for 6 shims. And waiting for them to arrive. .029 seems excessive. I know there is opinions about shimming or not to shim. I'll try shimming. anybody know of a source here in the USA? Or have extras to sell?
Click to expand...
It will be perfectly fine unshimmed.
 
Fast Eddie said:
It will be perfectly fine unshimmed.
Click to expand...
It will.

Or for an off the shelf shim to go under the bearing, look at VW crankshaft shims, nominally 10 and 12 thou thickness available. One of the thicker shims will work fine and give around 0.017" end float, middle of the MkIII spec!

Purchased from eBay. Febi Bilstein brand, part number, thickness in thousands of an inch and mm. #1738: 0.009488", 0.24mm. #1740: 0.011811", 0.30mm.

McMaster Carr does not ship to Europe.


​
 
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IMHO, shimming either the drive or timing side blindly to get the end float to a number is a mistake. If you assume that everything is manufactured correctly, then at a minimum when shimming, 1/2 of the desired shims should be on each side.

Again, IMHO, to actually blueprint, the crank should be shimmed to put the conrods in the center of their bores while the conrods are in the middle of their side-to-side movement.
 
The closest shims on the McMaster chart is...

2 3/4 O.D.

2" I.D.

.005 thick pack of 5 $9.12 McMaster # 970 22A 356

Next question...While measuring the bearing bore I noticed there is a baffle to the rear of the crankcase which gives a fairly high (in my opinion and not based on any engineering) level of oil in the crankcase before it is picked up by the sump filter. I'm guessing there is about 3 cups of oil while running down the road. Why so much? Seems like a lot of oil for splash feed.
 
That sounds like a 1972 crank case and the breather, the oil pick up is still at the bottom of the case.
The reason I machine my own shims to go under each bearing in the case is to avoid stacked shims, one shim under each bearing, it also reduces (halved) the stick out of the bearing race itself.
 
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This an 850 case, sump filter to the rear. I don't see any other oil pick up point.
I'm assuming you punch the shims from shim stock though that would leave a wrinkled edge. Yours look as good as it gets. I have a lathe but I couldn't shave off a .005 or .010 shim with great accuracy.
 
seattle##gs said:
This an 850 case, sump filter to the rear. I don't see any other oil pick up point.
I'm assuming you punch the shims from shim stock though that would leave a wrinkled edge. Yours look as good as it gets. I have a lathe but I couldn't shave off a .005 or .010 shim with great accuracy.
Click to expand...
Do you mean the raised dam (wall) at the back of the case, it is only one case half so the oil flows around it. (I had to machine it to get my Comstock reed valve to screw home as some engine cases have extra material on it and the riser tube contacts it)

crankshaft shims


crankshaft shims


As far as the machining jig, multiple shims were done at once, stacked up and clamped together tightly to become one so it was like normal OD and ID turning/boring.
 
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seattle##gs said:
You're right. So what's it's purpose?
Click to expand...

I guess it is a partial dam to hold oil around the pick up, that other part of the case above it might be a scraper to peel oil off the crankshaft to flood that lower area.

6:15 AM Downunder.
 
seattle##gs said:
This an 850 case, sump filter to the rear. I don't see any other oil pick up point.
I'm assuming you punch the shims from shim stock though that would leave a wrinkled edge. Yours look as good as it gets. I have a lathe but I couldn't shave off a .005 or .010 shim with great accuracy.
Click to expand...
When any shim is made, it needs to be stoned to remove any burrs on the edges that are felt with a fingernail
 
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