The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: ninny on 20.09. 2014 10:09

Title: Oil Line
Post by: ninny on 20.09. 2014 10:09
I am  getting close to completing a rebuild on my AA7 (short stroke motor).   When installing the oil line to the tappit covers, I noticed that there is a small bead inside the plastic tube which connects the oil line from the oil tank to the oil line to the tappit covers.  This bead has a very fine hole in it.  I am worried that this very small hole would not allow enough oil through to the top of the motor.  Is this small bead supposed to be situated in this oil line?  Any info would be greatly appreciated.
Title: Re: Oil Line
Post by: bsa-bill on 20.09. 2014 11:09
never heard of anything supposed to be in that line but haven't heard everything yet.
Possibly a PO attempt to restrict the flow to the tappets if there was excessive smoking or similar
Title: Re: Oil Line
Post by: RichardL on 20.09. 2014 15:40
I think the answer is "No", no bead in the line. You should be sure there is no issue with the hole size(s) in the rockerbox feed bolts. Look here: http://www.a7a10.net/forum/index.php?topic=2001.msg12809#msg12809 . (Maybe, even, look at the link on my post there. Been here so long it's hard to avoid myself.)

Richard L.
Title: Re: Oil Line
Post by: muskrat on 20.09. 2014 21:47
A PO has probably soldered the joint and not cleaned out the hole.
Cheers
Title: Re: Oil Line
Post by: duTch on 20.09. 2014 23:42
 
 I don't think they originally came with a plastic hose *conf*-rubber maybe, but a ball in there is like a non flow valve, *eek* get rid of it....!
 Also make sure you use banjo bolt with the right size hole, as too big a hole will supply to much oil and cause issues, as and Richard suggested, and to small, Weeeell...?
  They do come in different sizes..as I discovered....!
Title: Re: Oil Line
Post by: ninny on 21.09. 2014 00:41
Yes, I agree with you guys. This bead has a hole in it the size of a sewing needle and would restrict oil flow too much.  Thinks for the reminder about banjo bolt hole sizes.

see pics
Title: Re: Oil Line
Post by: ninny on 21.09. 2014 00:43
pic 2
Title: Re: Oil Line
Post by: Triton Thrasher on 21.09. 2014 10:59
Is it there for the same reason children notoriously put beans in their ears?

http://youtu.be/7YyGNybINeU (http://youtu.be/7YyGNybINeU)

Actually, if you really want to play around with oil supply to the top end, how about altering the restriction effect in the scavenge line, downstream of the takeoff to the rocker box? 
Not that I can think of a good reason to mess about with it.
Title: Re: Oil Line
Post by: ninny on 21.09. 2014 11:56
I have removed the restrictor bead and connected the pipes back up.  Will see how it goes.  I think too much oil to the rockers is better than not enough.
Title: Re: Oil Line
Post by: bsa-bill on 21.09. 2014 12:22
Quote
if you really want to play around with oil supply to the top end, how about altering the restriction effect in the scavenge line

not sure I like the sound of that TT.
I believe the small hole in  return pipe in the tank is BSAs preferred option, wonder if that's been tinkered with Ninny
Title: Re: Oil Line
Post by: Triton Thrasher on 21.09. 2014 13:06
Quote
if you really want to play around with oil supply to the top end, how about altering the restriction effect in the scavenge line

not sure I like the sound of that TT.
I believe the small hole in  return pipe in the tank is BSAs preferred option, wonder if that's been tinkered with Ninny

I know that some people do try reducing the diameter somewhere, to squeeze more oil up there. I don't know how they got on. 

Reducing oil supply to the rockers sounds mad to me and anyway the hole in that "bead" looks small enough to get blocked completely.
Title: Re: Oil Line
Post by: BSA_54A10 on 21.09. 2014 13:59
It used to be a fashionable modification .
We used to pinch off the oil return stand pipe to force more oil to the head.
I think it was started by some one who pined for the days of 2000 mile decokes as all the was accompliched was flooding the head and sucking a lot more oil down the inlet guide.
Hay but were all ace "tuners" when we war 18 wern't we ?
Title: Re: Oil Line
Post by: bsa-bill on 21.09. 2014 14:20
Quote
Hay but were all ace "tuners" when we war 18 wern't we ?

Hell no I got that far at 17 via a NSU quickly (not very), I probably held the record for maximum use at full throttle and number of drive shaft keys used in a year (until my dad cured that one with a home made, tempered key made from the end of a file, cured the key breaking issue but involved buying new drive shafts  *conf*
Title: Re: Oil Line
Post by: Triton Thrasher on 21.09. 2014 15:16
Isn't it strange: a teenager's assumption that the factory made mistakes that he must rectify with his dad's joinery screwdrivers and bed frame spanners!

That was me too.
Title: Re: Oil Line
Post by: bsa-bill on 21.09. 2014 15:21
or even a small bead with a hole in it *smile*
Title: RE: Oil Line
Post by: Rgs-Bill on 21.09. 2014 17:56
Here goes, I had an old timer BSA guy tell me he used to install the bulbous end of a medium sized cotter pin, into the oil return pipe in the oil tank, and then bend the feet around the tube to keep it there.  This creates a little more resistance to all of the oil going back in the tank, and sends more oil, (the old timer said 25% more) up to the rocker arms.  I asked Musky and bsa-bill about this.  They both agreed this was probably not a good Idea.  BSA did not do everything right in their manufacturing, but this oil feed factory made restriction must be right on, look how long it has worked for these bikes. REMEMBER also that originally the upper oiling was relying on the oil splash system.  Have you ever run your bike with the valve covers taken off and observed the goings on, well there is oil splashing every where, it gets thrown off of the tappet adjusters, if it is working as designed there is plenty of oil up there.  bsa-bill said sure you would have more oil in the cam trough (drains down the push rods to followers and cam) so no danger of starving the cam bushes for oil, but the PRV is designed to do just that.  Musky said he would be concerned that there might not be enough oil for the scavenge side, of the oil pump, to cope with it.  Both of these observations by them are very valid positions. It harkens back to >>  "if it is not broken do not fix it" .  NUFF SAID, please comment back on these observations, from your experiences with rocker oiling's.

                  RGS-BILL
Title: Re: Oil Line
Post by: bsa-bill on 21.09. 2014 18:07
Quote
Have you ever run your bike with the valve covers taken off and observed the goings on, well there is oil splashing every where, it gets thrown off of the tappet adjusters,

Good way to waterproof the leggings Bill
Title: Re: Oil Line
Post by: Rgs-Bill on 21.09. 2014 18:19
Bill. the part about a good way to water proof the leggings, well that is one I never thought of.  Really  a fun point !!!!
 *smile* *smile* *smile*  yuk, yuk, yuk,  etc.
Title: Re: Oil Line
Post by: Topdad on 22.09. 2014 10:46
Bill and Bill, Yep, can agree, took my tappet covers off to check how things were going quite a while back and soon had an oil splash zone around the bike that proved beyond dought that the oil was getting there ( thankfully )!! don't intend to do it again anytime soon , BobH.
Title: Re: Oil Line
Post by: bobandbec on 24.09. 2014 15:32
Just to digress slightly. What internal diameter should the oil lines on a 1960 A10 be, 5/16", 3/8".?  I thought they were the smaller but someone told me they were 3/8?
Thanks
Title: Re: Oil Line
Post by: Billybream on 24.09. 2014 19:37
Hi. I run 5/16" bore oil hose on my A10, and make the hose assembly with barbed type connectors which allow hose to simply push over, for extra security you can add hose clip.
Title: Re: Oil Line
Post by: bobandbec on 24.09. 2014 22:26
Thank You