1/8th NTP? connection for early Series 2 oil pressure gauge

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jagnut66
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1/8th NTP? connection for early Series 2 oil pressure gauge

Postby jagnut66 » Tue May 18, 2021 10:07 pm

Hi,
I am looking for the 1/8th NTP (I think that's right but please correct me) connection that screws in the engine block (1) mainly but if it comes with the pipe that feeds the gauge (2) so much the better.
Image below.
I anyone has one spare that they are able to let me have then I would be very grateful.
Many thanks,
Mike.
DSCF3833_LI.jpg
DSCF3833_LI.jpg (435.88 KiB) Viewed 295 times
1954 Series 2: 4 door: "Sally" -- on axle stands needing more welding......
1955 Series 2: Traveller: "Elsie May" -- on the road and enjoying her 'as is' for now but I see work ahead......
1970 Triumph Herald 1200: "Hetty" -- driven back from Llangollen in Wales

jagnut66
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Re: 1/8th NTP? connection for early Series 2 oil pressure gauge

Postby jagnut66 » Fri May 21, 2021 11:36 pm

Since posting this I have found this adapter on eBay (link below), which looks to be the right one, in case anybody else may find themselves looking in the future.
It has now been delivered and fits the pipe connection, so I now just need to see it screw into the block. I will report back.
Best wishes,
Mike.

https://www.ebay.co.uk/itm/273520725705
1954 Series 2: 4 door: "Sally" -- on axle stands needing more welding......
1955 Series 2: Traveller: "Elsie May" -- on the road and enjoying her 'as is' for now but I see work ahead......
1970 Triumph Herald 1200: "Hetty" -- driven back from Llangollen in Wales

Mick Lynch
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Re: 1/8th NTP? connection for early Series 2 oil pressure gauge

Postby Mick Lynch » Sun May 23, 2021 9:33 pm

jagnut66 wrote:
Tue May 18, 2021 10:07 pm
Hi,
I am looking for the 1/8th NTP (I think that's right but please correct me) connection
Could be a NPT? National Pipe Thread.

It’s a taper thread and the same pitch and diameter as BSPT, but slightly different angle. Both will fit into each other with some pipe dope or thread tape and make an acceptable seal.

Glad you found a part that works

jagnut66
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Re: 1/8th NTP? connection for early Series 2 oil pressure gauge

Postby jagnut66 » Thu May 27, 2021 6:38 pm

Could be a NPT? National Pipe Thread.
Sorry, yes, I meant NPT.

I can now confirm this screws nicely into the side of the engine, although it gets tighter the further in it goes and doesn't tighten in all the way, or at least I wasn't prepared to risk snapping it off in the block for the sake of about 3mm.
Which means the copper washer I put on isn't doing anything, so it can come off when I have cause (or inclination) to remove the adapter.
However, as it doesn't leak on test, I am happy with it.
With the new head on (8 new hardened valve seats, skimmed and lightly ported) the oil pressure gauge was nearly on 100 when I first tried it, from cold with choke, when it had warmed up it settled down to just under 50. This was whilst sat on the drive, so hopefully this is a good sign, as I haven't seen what it reads out on the open road yet....
Best wishes,
Mike.
1954 Series 2: 4 door: "Sally" -- on axle stands needing more welding......
1955 Series 2: Traveller: "Elsie May" -- on the road and enjoying her 'as is' for now but I see work ahead......
1970 Triumph Herald 1200: "Hetty" -- driven back from Llangollen in Wales

Boomlander
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Re: 1/8th NTP? connection for early Series 2 oil pressure gauge

Postby Boomlander » Thu May 27, 2021 10:49 pm

If there are no leaks then the tapered thread is doing its job.
I would check your oil pressure relief valve though as it should open at pressures above 60psi and 100 psi seems way too high on start up. :o


jagnut66
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Re: 1/8th NTP? connection for early Series 2 oil pressure gauge

Postby jagnut66 » Thu May 27, 2021 11:18 pm

I would check your oil pressure relief valve though as it should open at pressures above 60psi and 100 psi seems way too high on start up. :o
Interesting, I have fitted a classic Mini style one, as recommended by 'philthehill', which uses a ball bearing rather than a cap on the end of the spring, which I have been warned can jam closed.
Maybe I should reinstate the original Minor spring, whilst retaining the ball bearing rather than the original cap. The Mini spring was considerably 'firmer' and made it a hard job inserting the set up back into the engine.
Perhaps the new spring is too firm.
Best wishes,
Mike.
1954 Series 2: 4 door: "Sally" -- on axle stands needing more welding......
1955 Series 2: Traveller: "Elsie May" -- on the road and enjoying her 'as is' for now but I see work ahead......
1970 Triumph Herald 1200: "Hetty" -- driven back from Llangollen in Wales

Boomlander
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Re: 1/8th NTP? connection for early Series 2 oil pressure gauge

Postby Boomlander » Fri May 28, 2021 1:19 am

I did exactly the same with the relief valve on my Series II Jethro.
Struggled for ages to compress the spring enough to screw the cap in then on start up the needle on the oil gauge nearly left the housing.
A sadly missed senior member (Roy) put me straight and advised reinstatement of the standard assembly.
Sage advice as always! :D


jagnut66
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Re: 1/8th NTP? connection for early Series 2 oil pressure gauge

Postby jagnut66 » Fri May 28, 2021 9:18 am

Out with the spanners again then...... :wink:
Like I said I look to keep the ball bearing but reuse the original Minor spring, is this what you ended up doing?
Roy's advice was usually good, he spoke his mind too. :lol:
Best wishes,
Mike.
1954 Series 2: 4 door: "Sally" -- on axle stands needing more welding......
1955 Series 2: Traveller: "Elsie May" -- on the road and enjoying her 'as is' for now but I see work ahead......
1970 Triumph Herald 1200: "Hetty" -- driven back from Llangollen in Wales

philthehill
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Re: 1/8th NTP? connection for early Series 2 oil pressure gauge

Postby philthehill » Fri May 28, 2021 9:49 am

If you replace the oil pressure release valve cup the BMC wksp manual recommends that the cup is lapped to the valve seat but that means that you should afterwards thoroughly clean the engine to get rid of any lapping paste.
The reason(s) that the 5/8" ball bearing is recommended is that it does not need to be lapped in and it is near impossible for the ball bearing to stick which is a real possibility with the cup. If fitting the cup it is advised that several holes are drilled in its outer face to allow the release of any crud that gets trapped between cup and valve seat.
There are at least two springs that hold the valve cup to the seat. They are the standard Minor spring and the Cooper S spring.
If you have excessive oil pressure either spring can be shortened to reduce the spring load on the cup or ball bearing. The shortened end of the spring should be fitted into the cap. You can also fit an adjustable oil pressure relief valve cap which allows in conjunction with the shortened spring to set the oil pressure to your preferred setting.
Use the Minor oil pressure relief valve spring with the ball but you may have to shorten the spring to get the right oil pressure. Too much oil pressure is nearly as bad as not enough oil pressure.
See link below:-
https://www.calverst.com/technical-info ... oil-pumps/


jagnut66
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Joined: Fri Apr 11, 2008 7:28 pm
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Re: 1/8th NTP? connection for early Series 2 oil pressure gauge

Postby jagnut66 » Sat May 29, 2021 10:45 am

Use the Minor oil pressure relief valve spring with the ball but you may have to shorten the spring to get the right oil pressure. Too much oil pressure is nearly as bad as not enough oil pressure.
Thanks for the advice Phil.
If its still high when I start her next I'll shorten the spring.
Best wishes,
Mike.
1954 Series 2: 4 door: "Sally" -- on axle stands needing more welding......
1955 Series 2: Traveller: "Elsie May" -- on the road and enjoying her 'as is' for now but I see work ahead......
1970 Triumph Herald 1200: "Hetty" -- driven back from Llangollen in Wales


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