Pipe dreams!

[Worty]

For those of you who have an interest, I would invite your comments as to the conundrum which are BSP pipe fittings (this is in relation to my replumbing of the oil feed on the GF).

Given that the tank spigots are 1/4", as are the crankcase spigots, I was trying to work out what would work best for the maggy oil switch cut out tap.  This is what I found regarding BSPP and BSPT fittings.

1.  A male BSPT will fit into a female BSPP fitting, but not the other way round (so male BSPT to either female BSPP or BSPT).  If you happen to have a female BSPT fitting, it will ONLY fit onto a male BSPT fitting (not BSPP).

2.  When I asked if I could get an adaptor with male 3/8" BSPP to male 1/4" BSPP, I was told no-one supplies these.  The item I have is male 3/8" BSPP and male 1/4" BSPT.  However, I have found an adaptor with BSPP both ends, so WTF!

3.  When using BSPP to BSPP, the threads won't seal themselves so PTFE tape has to be used or a fibre washer (this makes sense with the oil tank setup which use BSPP threads).

I've not started with the male and female 60 degree cones either.

So far, I have the following.

From oil tank feed spigot, female BSPP 1/4" 90 degree equal swivel 60 degree cone.  This screws onto the BSPT 1/4" male adapter which, in turn, is screwed into the tap body.  The same arrangement using an identical adaptor  is on the other side with the oil pipe screwing onto the adaptor that side.  The oil pipe is turned around so the nipple end that used to screw into the tank spigot is now screwed into the crankcase side (like what Roger did elsewhere in the forum).  I take it there's no issue in the crankcase connection as there's no female cone on the crankcase spigot to accommodate the male cone on the oil pipe.  It does, however, seem to tighten up fine.

Anyone following this, or are you sound asleep?

[Swarfcut]

 These pipe threads come as parallel or taper thread forms, so for practical purposes will not mix.

  https://en.wikipedia.org/wiki/British_Standard_Pipe

 We are not concerned with high pressures, and a simple " tight on the pipe" push on rubber hose and clip will make an oil tight connection.  Auto fuel injection hose is fine, reinforced and has reasonable longevity.

 Compression fittings in metric sizes are readily available and far easier to connect up if you want solid pipework, just like domestic plumbing but on a smaller scale.

  Applying a male cone to a flange fitting means a minute surface area of contact, and a recipe for disaster. This does not sound right for the crankcase fitting.  Flange joints need a  soft washer between the faces to make the seal, retaining nuts are there to compress this, not act as a seal.

 Swarfy.

[chaterlea25]

Hi Worty,
The crankcase adaptor should have a 60 degree female taper to accept the oil pipe connection? If it hasn't maybe  the work of whatshisface

John

[RogerSB]

Hi Worty,  This is one of the drawings I made when I was getting some oil hoses made when fitting my tap, it illustrates what John was saying. Don't help with your tap connectors though
Rog.

[Worty]

These pipe threads come as parallel or taper thread forms, so for practical purposes will not mix.

  https://en.wikipedia.org/wiki/British_Standard_Pipe

 We are not concerned with high pressures, and a simple " tight on the pipe" push on rubber hose and clip will make an oil tight connection.  Auto fuel injection hose is fine, reinforced and has reasonable longevity.

 Compression fittings in metric sizes are readily available and far easier to connect up if you want solid pipework, just like domestic plumbing but on a smaller scale.

  Applying a male cone to a flange fitting means a minute surface area of contact, and a recipe for disaster. This does not sound right for the crankcase fitting.  Flange joints need a  soft washer between the faces to make the seal, retaining nuts are there to compress this, not act as a seal.

 Swarfy.

Cheers Swarfy. 

What confused me slightly is that the BSPT male will fit into a BSPP female, which I was told, originally, was incompatible.  Apparently, this does not work the other way round.

I'll look at all the fittings again and see what works.  I get that the male cone onto a flange fitting isn't really great, but I have an idea to get round that.

I want the maggie cut out oil valve to be mounted on solid pipework from the tank to avoid it flopping about, and wanted to utilise the existing oil pipe in the set up.  I think I have the tank to valve set up right, but want to ensure the flexi oil pipe from valve to crankcase is going to work ok.  I think it will, with a bit of innovative thought, but will see what transpires once it's all set up.

Unless I get a pipe made up, it looks like the existing flexi pipe is a bit longer than I'd want but, again, I have a cunning plan for this (if it works, of course?).

[Billybream]

BSPT Male to BSPP Female is almost industry std for low pressure connections, used in conjuction with thread sealer or PTFE tape, regarding cone fitting into flange, use of a Dowty seal should work, just ensure flat sealing faces to both.

[Worty]

BSPT Male to BSPP Female is almost industry std for low pressure connections, used in conjuction with thread sealer or PTFE tape, regarding cone fitting into flange, use of a Dowty seal should work, just ensure flat sealing faces to both.

Thanks BB!  Could you elaborate a little more on the cone fitting to flange, i.e, where would the Dowty seal locate and how do you get flat sealing faces.  With my set up, the flange fitting is large enough for the cone to sit about halfway inside it.  So, whilst it's not strictly a female cone to fit with the male cone, the male cone does locate securely and doesn't move once tightened.  I was thinking a bit of PTFE on the threads before belting it up would work?

[Billybream]

Sorry I was under the impression the fittings would bottom out and a sealing washer of some type would seal under the head. PTFE is a good sealing method, just have to be careful when applying to thread, that it does not wind out.

[Swarfcut]

    Both crankcase oil line adaptors are the same part 65 2252. Are you sure one is spurious or just buggered up by the likes of Rivet Man? Swapping out for a better, correct part would solve that conundrum without extra washers, tape etc, if you want to retain the existing cone type connection.  Otherwise keep the flange faced adaptor and make a flange connection on a new custom made up oil line.

 With those pipe threads  I hoped to make it easy to understand why threads that look the same but won't fit together has a simple explanation....some are tapered, some are parallel.

 Swarfy.

 

[Rex]

I always thought, and I could be way off the mark, that British bikes hardly ever/never used taper threads?

[Worty]

This is what it looks like folks - quite neat if I say so myself.

No leaks so far, will have to check when hot.

What's the oil flow supposed to look like at the crankcase end.  I have a rapid drip with cold 20/50 just covering the feed filter.  I know it'll be quicker when hot, but does the pump pull oil through as well?

As you can see, I've turned the oil line round again and fed it up between the engine plates which utilises the 90 degree bend quite well.  The pipe is also pretty well hidden too.  The cones on the tank swivel joint and on the end of the oil pipe seem to sit quite neatly into the adaptors screwed into the valve.  They only go about halfway in, but the nuts tighten well and will compress the cones into the adaptors (or so I'm hoping).  As I said, no leaks so far.

[chaterlea25]

Hi Worty,
That's very neat
Do you have a part number or link to the course of the swivel elbo? 
My brother  has bought the tap and is looking to source fittings for his 59 A10

John

[Worty]

Hi Worty,
That's very neat
Do you have a part number or link to the course of the swivel elbo? 
My brother  has bought the tap and is looking to source fittings for his 59 A10

John

Hi John

Swivel elbow - https://www.ebay.co.uk/itm/142826314751?var=441828840032

Adaptor (for my type of valve) - https://www.ebay.co.uk/itm/134319536811

If you're using the Magneto Guys' arrangement, I think it may be simpler.  The adaptors don't have a female cone, but are wide enough to accept around half of the male cone and the nuts tighten with no problem.  If there's any weeping, a wrap of PTFE should suffice.

As for the routing of the original oil pipe, it goes between the engine plates from the top, then back through the plate at the bottom.  The whole arrangement is very solid, but will monitor for vibration 'loosening'.  If that happens, a bit of medium threadlocker or a bit more PTFE should sort it.

Hope it goes well with your brother's setup

[BagONails]

What's the oil flow supposed to look like at the crankcase end.  I have a rapid drip with cold 20/50 just covering the feed filter.  I know it'll be quicker when hot, but does the pump pull oil through as well?

Looking good Worty.  To answer your question, when I remade my oil lines recently I was curious as to how much flow of 20w60 I was getting just by gravity from the tank down to the connection on the engine and it ain't much!  It was continuous flow tho rather than a fast drip 

The stream would only have been about an 1/8" dia. pretty underwhelming to be honest... like warm honey off a spoon if you get my drift? I didn't measure the flow over a minute in the end, not sure why, as I meant to but I'm pretty sure the oil pump will be pulling it through considerably faster and obviously this would only improve as the oil warms up. 

Have you checked your oil tank breather is clear?

[Worty]

Oil tank is spotless BoN, cleaned out with brake fluid to clear any debris out of the tank (not that there should have been any).  All lines blasted through with carb cleaner, etc, etc.  Could be a bit of an air lock/hydro lock somewhere, so will probably bleed the line before final testing.  I think with a full tank of oil, it'll push through a bit quicker, but the previous flow was as you described - a steady but fairly feeble flow.

The bottom line is that there's a clear passage from the tank through to the bottom of the pipe, so it must be a simple matter to improve the flow a bit.  To be honest, it's not far off a steady stream and I may not have given it long enough.  I do know the valve and pipework is clear as it was double checked prior to assembly.