Crank end float - best guess?

[limeyrob]

I'm swapping cases so I don't have a start measure for the crank end float shimming. I have the inner roller off and a few shims to hand.  What would be a good shim thickness to start?  Obviously I'm hoping to get it right first time and save loads of work . 
My best guess is around 0.010"

[muskrat]

G'day Rob.
You must start with NO shims to get an accurate measurement. 2 to 3 thou endfloat is what to aim for. This gives clearance when cold, you'd be surprised how that increases when hot.
It's a PITA I know getting the roller bearing off but must be done. Do a search for different methods.
Cheers
 

[Billybream]

Best to use a dummy bearing, with diameter relieved so it can be easily removed

[limeyrob]

That idea I like, I can mic the bearings and correct if there's any difference.

[KiwiGF]

That idea I like, I can mic the bearings and correct if there's any difference.

I used emery cloth in a lathe, it doesn’t much to remove the interference fit.

With just 2 thou end clearance there is still a big clunk when pulling the crank one side to the other.

[Colsbeeza]

Rob, Further to endorsing Muskrat's advice, I purchased two new roller bearings and relieved the inside of one as a test "spacer". However, upon measuring both new identical bearings one was 1.5 thou wider than the other so you need to measure both to calculate the correct shims. I aimed for 1.5 thou but got 1.8 after final assembly. I had 5 trial assemblies before I was satisfied.  For joining the cases in final assembly, I used Blue Hermatite and measured no change in end float.  You also might consider a NJ206 bearing rather than the standard NF206 which leaves the rollers in the outer case, so you can in future lever off the inner bearing without difficulty. Also ask for a C3 clearance bearing. Otherwise the rollers may be too tight when assembled. I would recommend you search "End Float" in the Forum archives for much more experiences.
Colin

[limeyrob]

Thanks all. My beginnings of a plan are to relieve the old bearing a bit, put in 10 thou then use feelers on the case joint in the fashion of a Velocette (which has preload) as this means I have a little gap to get the knife edge bearing extractor in. With Hylomar I think that will come up at around 1-2 thou so I'm thinking I'll set for zero then check on the dial gauge once bolted up with sealer, and pulled up hard on the drive nut. Obviously at this stage I'm not looking to have to make any changes.  Its frustrating becuse I had all the measurements ready then (and only then) noticed they were mismatched cases and had to start again with the matching cases.  My mistake was assuming anything about the engine build such as "of course they would use matching cases". Wrong.



.

[berger]

Colsbeezer i had problems using the two bearing method, i even mentioned it a long time ago on a crank end float discussion. i think it was something to do with the outer race lip and roller lengths being very slightly different. when i bolted it all up with the new bearing it locked the crank because i wasn't getting a true reading for the new bearing . i scrapped the idea and just used the bearing that was going in and gently clamped a puller on the inner race rollers to slide it off and fit the shims.

[sean]

makes me wonder how they were assembled in the factory ....
you can also get crank brgs with the nylon cage  which allows disassembly of the brg so no damage to the cage .

[limeyrob]

I do wonder when struggling with jobs like this how they did it on the production line with a couple of minutes at most to get it right.  My shed/workshop is about -2C just now and I'm thinking that would equate to about 2 thou pre-load to be right for an average day.  I think I'll wait.  Can't bring it in the kitchen like the"old days", SWMBO's body language was very clear

[Topdad]

I've only done this once and I think I was  born under a lucky star  or blind ignorance got me through it .  My second A10 a small bearing swing/arm  when bought had ane engine which ran but sounded like 2 skeletons f**king in a tinbox  . I had a thought that a plunger motors guts bwould fit fit and I knew where one was located from a friend who assured me it was a sound motor . Has you did in those days the engine found its way to my Bedroom for the princely sum of £5 !  I took the old engine there as well stripped it .The barells were very worn the big ends shot and timingside would have made a break for freedom any time soon ,cases were ok. I cleaned everything and was pleased with the results . pulled the plunger apart and it was a really good clean motor . compared and was satisfied it would fit keeping everything in the right place on rebuild it went together really well and I seem to remember fitting the later iron head in place of the plunger one . I thing I didn't even know about was end float but In must have just fitted it spun the crank and thougt ok ,They proved to be the best A10 engine , it was battered and took all the abuse and came back for more ,Itwas eventually sold for a few pounds as I'd secured a job sell ing bikes and got use of one as transport ,Next time I rebuilt one  I did know about it but went for an end feed conversion basically to avoid the grief   

[berger]

i really feel sorry for you guys with SWMBO's who don't let you play nice in the house. i would be looking at swapping mine if she didn't let me play. she now wants me to get a move on and time up the berglar build so i can get it out into the garage and into the frame. she wants betsy beezer back indoors for christmas so she can put the fairy lights on her. what you guys need is a SHED sign in the house and convince her indoors that your house is the shed. the only little problem i have is i forgot to get the thick cylinder head washers, anybody got 9 spare??.also to keep urma yondas petrol tank nice and warm it has it's own shelf, it is empty of course. my cat is chief mechanic and keeps an eye on my workmanship. i will have a beer to the bestest girl in the world

[muskrat]

makes me wonder how they were assembled in the factory ....
you can also get crank brgs with the nylon cage  which allows disassembly of the brg so no damage to the cage .

G'day Fellas.
Yes I use that type of bearing. Just pop the rollers out and use a bearing separator type puller on the inner.
I mark each roller so they go back in the same direction and order. That's probably a bit pedantic.
FAG NJ206E-TVP2-C3 Cylindrical Roller Bearing, Single Row, Straight Bore, Removable Inner Ring, Flanged, High Capacity, Polyamide/Nylon Cage, C3 Clearance, Metric, 30mm ID, 62mm OD, 16mm Width
https://www.amazon.com/FAG-NJ206E-TVP2-C3-Cylindrical-Removable-Polyamide/dp/B00631AWJO
Cheers
 

[sean]

I built my motor in the basement during covid …. Time was wasted with parts delays and the machine shop boring for liners wasted 8 months and I really wanted to get it out of the basement before I couldnt carry the lump up the stairs…. Not getting any younger is concerning , but all was good .