fuel line connectors 1/2 inch - 18 thread

[pcarew]

I wanted to connect a fuel pressure gauge to my elan fuel pump, but the fuel gauge connector has a different thread density.

The fuel pump connector is 1/2 inch 18 thread pitch I believe. The pressure gauge seems to be 20 pitch.
Car parts shops do not seem to have 1/2-18 fuel connectors. Anyone able to suggest a converter/adaptor?

Thanks
Paul

[tonyabacus]

Paul
Try your local plumbing store or one of the specialist tuning outfits like Dave Bean or RD both on your side of the water
Tony

[tonyabacus]

Paul
I was thinking a little more about your connector, it is likely to be a British Standard Pipe thread or depending whether it is the standard pump or an electric pump could be a Metric thread. So can you confirm what sort of pump you have and who made the gauge(British or other). Also do you need a connector with external threads at both ends or internal or a combination?
Tony

[oldelanman]

What fuel pump do you have ? The original AC glass bowl pump has 1/2"-20 UNF threads.

viewtopic.php?f=40&t=42686&start=

[h20hamelan]

I figure it’s gonna be a bit tough to find the exact one you’re looking for.
Easier might be to return the gauge, or go to a giant auto parts place for the fitting. But I fear you barking up a the wrong tree, as most are for domestic autos within the last 10 years. Specialty fitting place, or try Spruce Aircraft or McMaster Carr.
Sunpro should have it, this isn’t what you need but it might start the hunt.

https://www.amazon.ae/Sunpro-CP7573-Met ... B00029JXLG

[Fred Talmadge]

What I do, alt least with plumbing, is bring the parts to the store and ask, "I want to connect this to that" With the big box stores, at least you can try different fittings to see what fits so you are no longer guessing. I understand you may not want to take about the fuel system of your Elan.

[elans3]

If you want a pressure gauge to check what the carbs are getting, you should fit it at carb height ideally. I have a gauge with a T piece and two short lengths of fuel hose. When I want to check the pressure, I just undo the hose between the two carbs, and fit it temporarily between the two, I keep the gauge with t piece in the spares box in the back of the car.

[pcarew]

Hello and thanks all for your thoughts,
The car has a replacement fuel pump, but I happen to have the original AC (Glass Bowl) pump that I've just refurbished that I want to retro fit.

Both pumps (the current and the original) have 1/2 inch- 18 threads (I measured and counted the threads).

The reason for all of this shenanigans is that I've been having a weber flooding issue and the fuel pump might be part of the problem with it's fuel pressure, hence the wish to measure it and the desire to replace with the refurbished original.

Putting a 'tee' in the fuel line was a good idea, but my fuel line is steel braid and it doesn't look very easy to inset a Tee into it.

Paul

Fuel line

[h20hamelan]

Bolt in through a banjo fitting.
Yes, there are fitting for banjo to gauge.
What height is your fue at in carbs. Easy to measure off the car.

[pcarew]

I re-measured and now I think I may have made a mistake,
I'm now thinking that maybe the Fuel Pump thread is actually 1/2-20

[tonyabacus]

Elan3 has the right idea.
But you say you have a steel braided pipe. Substitute this with a length of rubber pipe.
1. Purchase a four way brass fitting with the correct thread to take the gauge and three hose outlets.
2. Next purchase some rubber fuel pipe of the correct diameter,
3. Cut the pipe to the length between the two carbs less the width of the "T" piece
4. Join the pipebetween the "T" piece and the carbs and clamp them up
5. Join the remainig pipe on the four way with the fuel pump (you may need a straight brass fitting with a thread to match the pump and a hose outlet pipe
6. Clamp up the fuel pump end

That is all you need, so now you can start up and check the pressure, but check at idle and with an open throttle to verify it is not over or under pumping
Tony

[pcarew]

Ok, I can definitively say I made a measurement mistake. The Fuel Pump is definitively 1/2inch-20 UNC.
I just ran out to the local parts store with the fuel pump in hand

(A nod to Freds suggestion)
What I do, alt least with plumbing, is bring the parts to the store and ask

and verified the thread.

I now have a 1/2inch-20 thread to barb fitting that I think I can attach via hose to the gauge.

[pcarew]

Elan3 has the right idea.
.....
That is all you need, so now you can start up and check the pressure, but check at idle and with an open throttle to verify it is not over or under pumping
Tony

Thanks Tony, if the barb to hose fitting doesn't work, I'll go down this path

Paul