Author Topic: wheres my little end ?  (Read 3193 times)

Online groily

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Re: wheres my little end ?
« Reply #15 on: 12.05. 2009 17:46 »
Sounds to me like a one-off failure caused by the bush starting to rotate in the rod. Wonder what sort of fit the gudgeon pin was when it was put together? Not sure with these engines whether, per book, the pin 'should' swivel on the piston, in the eye, or both. Personally, I like them to be a close sliding fit in the little end, and a tight one in the pistons when cold (in my world, that's where a rag soaked in boiling water wrapped round the piston for a couple of mins is enough to allow the pin to move without the application of undue force). But there be varying opinions on the subject, I know.
 
Were it me, I'd just strip and clean everything - and then clean it again - with special attention to the oil tank, lines, drillings, traps etc and liberal use of compressed air, have the rods checked for ovality at the little ends, fit new bushes and ream them if necessary to get a no-play sliding fit (which takes just modest finger power to push the pin in and out). Plus check the gudgeon pin(s) very carefully for damage on any bearing surface, ditto piston. Replace as necessary, erring on the side of paranoia.
 
Reassemble and cross fingers for better luck. The which I wish you!
Bill

Richard

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Re: wheres my little end ?
« Reply #16 on: 12.05. 2009 19:05 »
I notice one thing that no one has yet mentioned the timing side bush if this is worn then oil pressure will be down, resulting in less oil getting to the left side.How I was told to do a quick check my the original Mr SRM was to remove the timing side cover and see if there was any up and down movement on the crank.
Its worth checking anyway.
The hole in the left hand rod was not there on the early engines but was included later with the thought that this would splash some oil in the bore and aid lubrication
IKBA applies
Richard
Richard

Offline A10Boy

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Re: wheres my little end ?
« Reply #17 on: 12.05. 2009 19:49 »
Its enough to make yer brain hurt.....
Regards

Andy

1960 A10 - Black Golden Flash
Plus
1974 Kawasaki Z1a
Yam XJR 1300

Offline mrshells

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Re: wheres my little end ?
« Reply #18 on: 12.05. 2009 21:02 »
If it were me, I'd replace both bushes while I was at it. You might also want to wait on that parts order until it's apart, you are bound to need more.

I think you need to inspect and plastigage the big-end bearings.

Did plastigage exist in 1952 ?
rod measures up No play in the big ends OK so its 2 new little end bushes which were £6.50 each from dragonfly
the dearest bit was the reamer to get the bushes to the right size
a good flush of the oil tank pump etc
then its back on the road

Online bsa-bill

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Re: wheres my little end ?
« Reply #19 on: 12.05. 2009 21:15 »
My crank was tested out of the bike by local machine shop and they commented they could not get equal flow to both sides - left side had less.
Wonder if it has something to do with centrafugal force combined with the sludge trap -  don't know ?
I got a nice set of reamers from RGD tools ( might be RDG even ) about nine or so in the set I think all adjustable - cost about 35 pounds or so,
I needed two gearbox bushes reamed and reckoned it would cost me around that to get it done in a shop so might as well have the set.
Do google for RDG or RGD and have a look

All the best - Bill
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Online groily

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Re: wheres my little end ?
« Reply #20 on: 12.05. 2009 22:09 »
RDG or RGD even do good stuff . . .  for the money  - I bought a couple of their boxed sets a while back and have done a fair few bushes with them since.
It wasn't until I was lent a serious (adjustable) reamer from a machine shop (for a swinging arm) that I realised how these cheap things compare with professional tooling . . . truly no comparison even though they work.
But anyway, several (gearbox) jobs done and so far, plus one little end, and no problems. Classic case of 'You get what you pay for'?
Bill

Online RichardL

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Re: wheres my little end ?
« Reply #21 on: 12.05. 2009 22:20 »
Groily,

I know this is runnin' wild off the topic, but did you need the reamer for the swingarm because the inside bushes didn't line up after busting a blood vessel to get the silent-blocs in place. Anyway, that's why I bought one.

Richard L.
Plan on signing up for the world-wide 2017 DISTINGUISHED GENTLEMAN'S RIDE on September 30, 2018. Watch website at https://www.gentlemansride.com for details.

Offline mrshells

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Re: wheres my little end ?
« Reply #22 on: 19.05. 2009 23:41 »
found it !!! *smile*!!!
any one good at brazing ?
need this lot putting back together !!!! *smiley4*

Online groily

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Re: wheres my little end ?
« Reply #23 on: 20.05. 2009 07:13 »
Blimey! Now that's a jigsaw puzzle! Good to have found (some of) it though . . . I suppose!

Re reamer Richard, it was actually for a Velo single swinging arm and was borrowed from an engineering shop - lovely thing and probably worth more than the 2 whole boxed sets I got from RDG! Touch wood haven't had to replace any BSA s/arm bushes .. . a bridge to cross in due course no doubt!
Bill

Offline rocket man

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Re: wheres my little end ?
« Reply #24 on: 24.05. 2009 20:20 »
looks like most ove it but is there eny more left in the oil passege ways
you can never be too carefull its worth stripping it down if youve removed
barrels and head why not go the whole hog then you will know for sure

Offline MikeN

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Re: wheres my little end ?
« Reply #25 on: 24.05. 2009 21:43 »
Have you measured the bore in your con-rod little-end eye yet? I hope its not been damaged by the pin rattling up and down and your new bush is a good fit.
Mike

Offline mrshells

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Re: wheres my little end ?
« Reply #26 on: 30.05. 2009 18:58 »
got her all back together now
Ive done about 50 miles and all seems ok  *smile*

Offline rocket man

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Re: wheres my little end ?
« Reply #27 on: 30.05. 2009 19:05 »
good luck did you strip down crank cases to see if
there is eany more bits left in her i would have done that just to be on the safe side
and is your little ends alright because if there is eany play there
the same thing will happen again