Air regulation for my Engine

[Iain DownsParticipant @iaindowns78295]

Soon (in a relative way) I will have got my engine in a place where I can push some air into it and hope that it turns round.

What I'm looking for is a regulator which I can control at the bottom end of the pressure scale (I hear posters boasting of their engines turning over at 2psi or less).

So I want something to do two jobs. Firstly to regulate up to a couple of bar with some granularity and secondly to have a tap on so I can turn it off quickly.

Or do you professionals just turn the regulator tap to start and stop?

Any advice welcome!

Iain

[Iain DownsParticipant @iaindowns78295]

Buying advice

[Jeff DaymanParticipant @jeffdayman43397]

Granularity?

any regulator 0-100 psi and a ball valve next to it for on/off would do

[JasonBModerator @jasonb]

I use the compressor regulator to set the pressure that I want ( yes I'm a low psi man)

The speed is then regulated buy a second flow valve which I find far more controllable than a ball valve. I use several of the the push fit ones of various sizes screwed into a manifold but you could just use a single one in the airline.

You really only need to adjust the pressure if the engine is put under heavier loads as the speed can easily be adjusted with the flow valves, couple of examples where the pressure is constant but speed adjusted by the flow valve. They can also be screwed shut to stop the engine which needs a couple of turns if you want instant ON/Off then that's what a ball valve is best at and fitted just after the compressors regulator.

[Brian MorehenParticipant @brianmorehen85290]

A compressor regulator as shown when adjusted will give you 2 bar and more ,your compressor may well have one fitted . To have precise control of the air to your model you require a needle valve which you can open to a suitable pressure which the more you open this the more bar pressure you will supply to your model.

I have just built a small osillating model with my lathe that runs on 4 bar . Has only taken me over 40 plus years to decide that I had the time for this , Hope to add a photo soon.

Regards Bee.M

[Iain DownsParticipant @iaindowns78295]

Thanks, Jason.

I've had struggled my way through amazon to work out the ancillary bits needed to hook up the regulator and so on. And purchase them.

I got to the end to find that the Amazon version of the regulator will take a month, so I went back to bearing boys. Should have stayed there in the first place.

Many thanks.

Iain

[JasonBModerator @jasonb]

The needle valve won't alter pressure, just volume of air or steam for that matter that can get to the engien. On an unloaded engine i's all about the volume of air getting into the cylinder.

My compressor reg will go right down to zero bar but most of the small double acting engines I will set it to 0.2BAR (3psi), single acting usually need a bit more about 0.6BAR (10psi)

Another example in this video compressor remains set at 10psi, for the first 90secs I'm making use of the reverser to alter the cut off so speed changes relative to how much air can flow into the cylinder. After that I'm using the flow valve to get speed right down to a tick over or going like mad. Too high a pressure on an oscillator will lift the cylinder off the port face or need excessive spring tension and therefore friction to keep it on the face.

Edited By JasonB on 25/09/2021 13:05:25

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