Oil hole confusion

[duTch]

 Interesting stuff, as it's only being flung to the barrel skirt around TDC~, otherwise it's just being squirted to the inside of the flywheel.....

   Maybe Briz, if you considering this as an R&D for your Bonneville Hotrod....?

  If you come good on this project (and good luck too), maybe they'll take heart, and rename Bonneville- 'Beezaville'..?

[Russ]

Thanks all for your input, much appreciated. I am no longer confused.
Russ

[muskrat]

  otherwise it's just being squirted to the inside of the flywheel..

At a few thousand revs it will fling off the flywheel up the bore.
Cheers

[bsa-bill]

But where is it being flung from? That little hole would put some on the flywheel and maybe on the bottom of the piston skirt, but if I am correct

From the point of view of cooling it maybe doesn't matter too much where it's flung precisely, even in the air it will transfer/carry heat away from that area so if it does just catch the bottom of the cylinder that would do, the heat dispersed from the part it hits (or air around it) would be replaced by heat from the rest of the barrel in that area.

If it was unnecessary why did BSA continue it on the A50/60 range.

Agree Muskrat they smoke more on the left but not always mine does sometimes smokes on the right, however thinking about it if that little hole
is working then there will be more oil in the left side than right to burn, interesting if a few of you who run bike pre little hole could comment on where yours like to smoke from we might conclude something - ummm maybe we wouldn't

[bsa-bill]

Thanks all for your input, much appreciated. I am no longer confused.

Sorry Russ - looks like we failed then

[Briz]

Interesting stuff, as it's only being flung to the barrel skirt around TDC~, otherwise it's just being squirted to the inside of the flywheel.....

  Maybe Briz, if you considering this as an R&D for your Bonneville Hotrod....?

 If you come good on this project (and good luck too), maybe they'll take heart, and rename Bonneville- 'Beezaville'..?

LOL!
We'd have to make a pretty big splash to accomplish that!
Unfortunately, with almost no BSA major internal parts, the experiment would be a bit flawed

[olev]

Gday,
I'm probably wrong here but it looks like the hole in the side of the crankpin only matches the hole in the big end shells when the piston is half way up the bore.
When the motor is running, the two holes aren't going to be lined up for long.
It would seem only a gnats *** worth of oil would get out even at low revs??
cheers

[bsa-bill]

looks like the hole in the side of the crankpin only matches the hole in the big end shells when the piston is half way up the bore.

Are you saying these holes match up ? I thought the idea was that the small hole was fed from the pressure between the shell and the crankpin with the help of  centrifugal force

Seems not a great idea to design a built in leak into a bigend to a cylinder that's  overheating anyway and reduce pressure to the bigend once every revolution, plus given the size of the small hole and float on the bigend I wonder if you could guarantee that the holes would be in sync often enough.

Ah well given we can't go back and ask anybody we might just have to wonder ( wonder how on earth the things still go when we keep finding so many faults in the design)

[KeithJ]

Interesting thread.  Can't see why it is important for the holes to line up unless to do with "rolling pressure".  Perhaps its the film of oil in the bearing and the pressure build up caused by the crank pin rotating is a key factor?  At some time will the holes be in the oil film be at higher or lower pressure?  As long as the oil gets around the bearing and out the other side, all should be well.  ATB

[duTch]

  Caaarn Brizzo, All the way ta Beezerville, superficialities will be fine, if it looks like a Beeza, it's a Beeza...

 

looks like the hole in the side of the crankpin only matches the hole in the big end shells when the piston is half way up the bore.

,
 

reduce pressure to the bigend once every revolution,

 Beg to diffre Bill (that's the French version), there's two holes so it gets a squirt on the down-stroke also....?? which would likely do farque-orl, except be scraped straight into the scavenge zone.....??

 A bit off tangent,
           I have a Lister 3-1/2 HP that I've spent some intimate time with, and it has no oil pump, just relies on splash lube, via a tang on the bottom of the big-end cap, and on either side of the rod is a oil feed hole into which -funnily enough- oil is fed, well funnelled really, as the holes are about from memory~ 3/16" (give or take an inch~), with a big entry bevel. The big-end shells have (originally had) scrolls carved into them to direct the oil, kinda like in g'box/cam/idler bushings, and that is the total oil feed.
 And last time I used it worked fine. must tend to that too.....