Identifying a thread.

DaveEFI · Post by **DaveEFI** » Fri May 13, 2011 1:38 pm

Flapper injection inlet manifold.

On the back of the housing the thermostat fits in - underside of the manifold - there's a threaded hole approx 3/4" diameter. On some applications it's blanked off with a screw in plug but on the SD1 there is a steel pipe which feeds the heater. This pipe is NLA - so I'd like to be sure what the thread actually is. BSP, UNF, etc? The EFI side seems to be a mixture of every thread known to man...

The thread is the only seal, so it needs to be a good fit.

Hotwire manifolds don't have this hole at all.

SimpleSimon · Post by **SimpleSimon** » Sat May 14, 2011 4:31 pm

Hi dave,if its about 3/4 why not go to a friendly plumbing shop and ask if you can try some of there pipe bungs(they stock lots)you can then have a play on the counter to see if any fit this the hole

got to be worth a go.

ChrisJC · Post by **ChrisJC** » Sat May 14, 2011 6:43 pm

The microfiche doesn't give a thread size, but I would expect it to be BSP if it's a pipe. Possibly BSPT.

Chris.

ged · Post by **ged** » Sat May 14, 2011 6:55 pm

Dave,

I've just measured one. The thread is 3/4" U.N.F.

Regards Ged.

DaveEFI · Post by **DaveEFI** » Sun May 15, 2011 7:56 am

SimpleSimon wrote:Hi dave,if its about 3/4 why not go to a friendly plumbing shop and ask if you can try some of there pipe bungs(they stock lots)you can then have a play on the counter to see if any fit this the hole got to be worth a go.

As I said you can quite easily get a thread that 'fits' - ie, roughly the correct diameter and with the same threads per inch - but for an good seal it needs to be the correct one. Unlike most things, this doesn't clamp down onto a face, so you can't use a sealing washer, it's all down to the thread.

Domestic plumbing bits are usually BSP.

DaveEFI · Post by **DaveEFI** » Sun May 15, 2011 7:57 am

ged wrote:Dave,

I've just measured one. The thread is 3/4" U.N.F.

Regards Ged.

Thanks, Ged.

ged · Post by **ged** » Sun May 15, 2011 8:23 am

I forgot to mention that there were traces of sealant on the thread, similar in appearance to the OEM head bolt sealant. PTFE tape or Plumbers Mate would do the job.

Regards Ged

DaveEFI · Post by **DaveEFI** » Sun May 15, 2011 9:11 am

ged wrote:I forgot to mention that there were traces of sealant on the thread, similar in appearance to the OEM head bolt sealant. PTFE tape or Plumbers Mate would do the job.

Regards Ged

IIRC, the OEM sealant is Scotch-Clad 776. Which I have. But PTFE tape should do just as well.

DaveEFI · Post by **DaveEFI** » Sun May 15, 2011 11:31 am

Anyone got a source for the blanking plug? Can't even find it listed on Rimmer's site. Brass, rather than steel, would be great. It's sort of similar to a sump plug.

unstable load · Post by **unstable load** » Sun May 15, 2011 12:14 pm

Git thee doon t' yon local hydrobolics shoppe for that plug.
Local plumber's merchants could also possibly help...

ged · Post by **ged** » Sun May 15, 2011 5:19 pm

If we're still talking about 3/4" UNF here's a couple. Unfortunately not in brass. One is plated steel & the other is stainless.

http://www.kiowa.co.uk/products/unf_hyd ... _plug/FUP8
http://www.flowtech.co.uk/browse_produc ... ng%20Plugs

Regards Ged