The BSA A7-A10 Forum
Bikes, Pictures, Stories & more => Chat, Offtopic & Everything Else => Topic started by: Worty on 14.05. 2025 18:06
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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?
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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.
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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 *eek*
John
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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 *sad2*
Rog.
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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?).
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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.
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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?
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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.
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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.
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I always thought, and I could be way off the mark, that British bikes hardly ever/never used taper threads?
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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.
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Hi Worty,
That's very neat *smile*
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
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Hi Worty,
That's very neat *smile*
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 *smile*
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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 *eek*
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?
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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.
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Worty that is neat and i bet you're rate chuffed wit result lad *wave* *beer* *good3*
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Rate (as Bergs would say), I have all the plumbing and electrics done. Oil flow is fine now there's a bit more oil in the tank.
If you look at the pictures, you may notice the small, plastic plunger on the earth wire on the valve. I was told this needed to be IN for the bike to start, and OUT when the oil's off. This is bollocks - good job I tested it with the plugs out and checking for sparks. Turns out it's the opposite way round. This meant having to undo part of the plumbing, move the switch 90 degrees, then replumb - all is good, no sparks with the oil off. This unit has two earths, one to the maggie and one to the frame - not sure why the body of the valve has to be earthed though. The little knurled knob on the maggie that secures the cut out wire is absolutely s*****d, so I had a hunt around. The first nut I found that was about the right size fitted perfectly, just needed a couple of washers to tighten properly and jobs a good 'un.
Quick question. It looks like the banjo on the return is still weeping where the big nut is that holds the banjo on. Will a judicious application of PTFE up to the banjo help fix the issue when the nut is put back on, or should I avoid PTFE in that area (dont' want to risk blocking anything)?
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Quick question. It looks like the banjo on the return is still weeping where the big nut is that holds the banjo on. Will a judicious application of PTFE up to the banjo help fix the issue when the nut is put back on, or should I avoid PTFE in that area (dont' want to risk blocking anything)?
Use Some Loctite blue on the thread. Worked for me alright
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PTFE is more than adequate for a good seal.
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Would a 1/4" Dowty be suitable, or would it be too thick?
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This may be a stupid question, but I'll ask it anyway.
If you remove the return side feed and banjo at the tank, will it leak oil out if you have a full tank of oil. I'm guessing some will leak out from the pipes but, given the return hole in the tank is above the oil level, theoretically no oil should come from the tank. This would also make sense as one wouldn't want a flow of oil into the return from the tank. I suppose it could be another way of testing whether the pipe inside the tank is in good condition.
Shoot me down folks.
I'm only asking to see if I need to drain the tank again to seal the leak around the banjo nut.
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Hi Worty,
You assumptions are correct *smile*
A too thick washer inside the banjo would make the pipe union nut foul the banjo nut and not seal!
Here's a theory *eek*
The banjo locknut can leak along its threads as there is nothing to seal them?
I'm thinking that's where mine weeps from?
I would worry that ptfe tape could get into the return pipe or rocker feed and cause problems??
When you come up with a. permanent fix let us know *????*
John
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Cheers John
I'm pretty sure a weep from the banjo locknut is responsible for the coating of oil down the r/h silencer and rear footrest! As you say, no seal on the threads at all.
Given that the bore of the rocker feed is so small, it wouldn't take much to block it with some errant PTFE or sealant (although others have had success with both, as I understand).
There's always a way to fix a problem! Watch this space for any possible solutions *smile*
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if someone's made a pipe joint and the PTFE has got inside the pipe then clearly they've done it wrong.
When the nut is screwed on the PTFE will tend to get "pushed" down the thread, ie, further away from the open end.
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if someone's made a pipe joint and the PTFE has got inside the pipe then clearly they've done it wrong.
When the nut is screwed on the PTFE will tend to get "pushed" down the thread, ie, further away from the open end.
I see what you mean Rex. Having thought about it, any PTFE put on where the nut is can't really be forced past the fibre washer and banjo. In fact, if the PTFE is pushed toward the fibre washer, then it will help forge a seal against the washer as well as the threads. I'll give it a shot - I'm more confident now that the PTFE won't make its way into the banjo.