FAG superblends

Hi, I already have an ad' in the wanted section but I thought I'd try here also. I'm after a set of discarded super blend crankshaft bearings so I can get them machined to ease installation and removal in order for me to check end float, anyone got a pair lying around they'd like to part with? cheers, David

Just buy cheapest roller available.

http://www.ebay.com/itm/N306E-2306E-30x ... Sw-K9ZFVJw

$13.16 or best offer inc shipping if in US.

SO,... You're trying to avoid the hassle of assembling the crankcase twice by having a pair of loose fitting bearings that drop right in the cases so you can measure your crank end play for shim requirments on an easy to assemble/disassemble dry run assembly. Correct???

I wonder how the factory did measured their end play. Does anyone know??? Did they have a fixture to take the place of the crank and bearings to measure case width, or did they assemble once, measure each assembly's end play, then disassemble to add the required shims for a second assembly?? Anyone know how the factory did it??

I would be surprised if the factory did much more than grab the end of the crankshaft after assembly and check for end float, float and off it went.
With two dummy bearings you minimise repeated removal of the stock outer's (interference fit) you can also easily check on centre for the bores (give or take a 'thou)
Just detail, plenty of folk torque connecting rod bolts in general without blocking (feeler gauge) the side clearance twisting the rod on the journal.
If you had large enough measuring tools you could probably measure the inner width at the case bearing bores and compare that to the width at the crankshaft outer journal thrust faces.

How many times are you planning to do end float checking?

Some use a 'used' inner section and enlarge in the inside (emery) until it slips on and off the timing side of the crank, what more do you need?

What's the problem with the twisting of the conrod when doing up the big ends? With about 0.005" clearance it's unlikely to do any damage to the shells.

gripper said:

What's the problem with the twisting of the conrod when doing up the big ends? With about 0.005" clearance it's unlikely to do any damage to the shells.

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That is exactly what I thought, did you ever see anyone recommend you do that?

o0norton0o said:

I wonder how the factory did measured their end play. Does anyone know??? Did they have a fixture to take the place of the crank and bearings to measure case width, or did they assemble once, measure each assembly's end play, then disassemble to add the required shims for a second assembly?? Anyone know how the factory did it??

Click to expand...

Sure, none with roller bearings were checked or shimmed from the factory. [and I have never seen a problem because of it] Jim

Yes , I've never seen an issue with crankshaft end float. So many other issues to deal with on a Norton. Use Superblends always. Beautiful bearings .

Engineering tolerances ensure that all the bits fit together properly. I believe Henry Ford was the instigator of production line engineering. Until recently ( 20 years ago) if you bought a new panel for your Morgan sports car it would have to be "fitted" How quaint.

Yes I have a pair I just replaced them I'm not back in NZ till Sept if you can wait I will send them over to you

comnoz said:

o0norton0o said:

I wonder how the factory did measured their end play. Does anyone know??? Did they have a fixture to take the place of the crank and bearings to measure case width, or did they assemble once, measure each assembly's end play, then disassemble to add the required shims for a second assembly?? Anyone know how the factory did it??

Click to expand...

Sure, none with roller bearings were checked or shimmed from the factory. [and I have never seen a problem because of it] Jim

Click to expand...

Thinking about this a bit, trying to meet the assembly tolerances is akin to trying to hit the side of a barn with a rock while standing right next to it......in my opinion. At least one of my manuals calls for no less than 0.005" and up to 0.015" end float though I recall it may have been specified a bit greater tolerance elsewhere so that leaves at least 0.010" to play with. I doubt the bearings supplied (at the factory, OEM replacement or another supplier) will have much of any significant variance. My hunch is the factory set up machining and gauged the first few parts and perhaps in process checks and then the acid test was some crusty old fella right after crank-in-cases assembly grabbed the crank, gave it a good yank and with decades of experience would say yea or nay. Probably a dial indicator and a quick end float check.

I say 0.010" is a big target, especially given the number of controlled (bearings) and presumably not so controlled (cases, flywheel and crank cheeks) components involved.

Here is what I did. Measure the distance with the crank and new superblend bearings assembled. Measure the distance between the bearing surfaces with the just the cases assembled. The difference gives you the initial endplay. When I re-assembled with shims for real endplay was pretty close to desired.

George