I need to find six vacuum take-offs for my TB project and they need to be quite small but still have enough bore to do their job (~3mm hose) 1/8"npt grease nipples would appear to be cheap and plentiful and I wondered if anyone can forsee any problems using them. Any other suggestions would be welcome as always

[Edited on 11-9-10 by RazMan]

what about .8mm Mig welding tips ?

Threaded and often have a flat on the end to wind them in.

The grease nipples have sprung loaded bearings to keep water / dust out will they alter the readings ?

a Grease nipple works that positive pressure on the out side pushes the ball down and positive pressure on the inside holds the Ball against the sealing face. Using it to plug a TB will not work as the TB is negitive pressure on the inside.

So theory is that as you increase the vacume then the ball may be pulled away fro the sealing face and draw in air..

However I doubt the engine will produce a big enough vacume to cause this to happen

lpg injection nozzels

Go to and industrial hose supplier and ask for some air fittings to suit 3mm nylon air line as used on industrial machinery.You will get a choice of thread sizes such as 1/8 or 1/4 bsp or metric etc and can also get tee pieces etc with matching hose.
Paul

Excellent ideas and explanations there chaps - I didn't think of going to my local hose supplier (duh!) so I will do that next week.
p.s. most of the air and lpg fittings are a tad bulky for my application but thanks for all the suggestions

Can't you just drill out the grease nipples so they are permanantly open?

How about THESE

If you have a lathe I'd be inclined to make exactly what you want from brass hexagon bar.

quote:

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Originally posted by 2cv
If you have a lathe I'd be inclined to make exactly what you want from brass hexagon bar.

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