wheres my little end ?

[mrshells]

Been out for a ride today and she developed a knocking
almost like a tappet rattle
which got worse !
much worse !
when I got her home  I found after removing the barrels
the little end had gone on the left hand cylinder
Really gone !
As in not there!!!
like some one stole it or forgot to put one in
I know it was ther when I built the motor last year ????

I think i may have to wash it from the sump

[LJ.]

OH no! thats bad news... Hope you managed to get it all sorted out soon. Sorry I did not get to the Wolds run last week, I was away at an Old Pupils reunion lunch with the Missus down near Gatwick, I hear it was a great ride. 

[rocket man]

ive never heard ove a little end wearing out in such a short time
was it a pattern one or an original carnt be too carefull these days
there are a lot ove substanderd parts out there

[shabashow]

I just finished rebuilding mine after the right hand little end broke into a thousand pieces. That was about 350 miles after its first rebuild! Some of it was still wedged between the conrod and piston.
The oil was a fine suspension of golden flakes, and there were a few scores on the crank. They  polished out ok. Everything needed stripping and cleaning.
Should have replaced the old one at that time, but, you live and learn.
If yours broke up, there should be pieces everywhere, especially on the screen filter in the sump.
Good luck in finding it!
John

[A10Boy]

Oh dear, thats bad news. If it broke up, there is going to be bits of it throughout the oil system. You will obviously need to strip the motor and clean it out. Bits of it are likely to be in the oil tank, pump, sludge trap and pressure release valve too.

Good luck.

[mrshells]

theres bits of bearing everywhere
my No 1 concern is that the rod isnt oval
dont know how long its been in there but it was there when i bought it 1500 miles ago
will order a new bush tomorrow and start stripping for a clean up
Summer is allmost upon us and I need to be riding it not looking at a pile of bits !!!

[rocket man]

good luck mate

[a10 gf]

I need to be riding it not looking at a pile of bits !!!

I know the feeling. Best wishes.

[RichardL]

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.

[RichardL]

OK, I'm getting that "obsessed with the issue" feeling.

Why the left side and why at all? Obviously, oil starvation. But the left side has this little hole in the hollow of the rod that, some say, squirts oil on the side wall of the cyclinder to add lubrication on the left side. However, I think the hole is there, at least mostly, for allowing oil to flow through the crankshaft journal, for both big-end bearings, without being held back by air pressure in the crank or slow flow through those bearings. So, say it squirts on the cylinder wall and is scraped into the inside of the piston where it drools onto the gudgeon pin and lubricates the small end. Other lubrication mechanisms are splash and mist. Anyway, I am not coming to a conclusion here. I just wanted to get the ball rolling, discussion-wise, to be sure there is a diagnosis, such that another occurance is not in the offing. Minimally, I think, be sure the little hole is there and it's clear.

I look forward to hearing from you and others with hypotheses as to why the left and why at all?

Richard L. 

[bsa-bill]

Now then Richard , if the hole was there to allow oil flow it would not matter which way the hole faced.
It is written that it should face inward to the centre of the barrels, this would make sense in as much as there were apparently problems with the left side overheating and it would surely be the centre of the barrel that overheated?.

There now let debate continue.

All the best - Bill

[Dynamo Regulators Mike]

Richard, funny how many threads, especially of late, relate to oil system faults or weaknesses.

One thought is that the LH cylinder, even with the hole in the rod still gets less oil than the timing side piston which benefits from inevitable leakage around the timing side bush at high pressure (if you are lucky). It has been asserted that the LH big end gets less oil than the RH as it is further from the pump. But the symmetrical feed from the sludge trap tube makes a nonsense of this.
Looking forward to other insights . . . .

[RichardL]

Interestingly, billet rods from MAP (also sold by SRM) do not include the little hole, as they say "don't need it." (Loosely quoted.) I couldn't live with the idea that the likes of Roland Pike probably thought the hole was needed, so I drilled my own.

Also, the billet rods do not have bronze bushes. The gudgeon rides on the aluminum.

Richard L.

[beezalex]

I'm thinking that the "High performance" rods (carrillo rods don't have holes either) don't have the oil hole because it creates a stress point and likely starting point for cracks.  A high-revving motor should also have enough spray to keep the DS bearing and cylinder wall properly lubricated.

[RichardL]

Alex,

I think that means I did the right thing in drilling the hole, as I've no intention of revving to racing speeds.

Richard L.