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Member postings for Brian John

Here is a list of all the postings Brian John has made in our forums. Click on a thread name to jump to the thread.

Thread: Building the twin cylinder 7BIM engine.
16/10/2014 12:09:14

No, even when I was running it on one cylinder at a time, both sets of pistons and valves were connected to the axle and flywheel with their eccentrics and cranks so the amount of friction is still the same.

I think I am losing much more air than I first thought. Tomorrow I will try sealing all the pipe work with either plumbers tape or Loctite 567.

15/10/2014 10:01:16

Yes, I do have a moisture trap. I was not aware that the full size fittings had tapered threads.

15/10/2014 06:38:57

I have been running the engine with some oil in the displacement lubricator and I now have some oil leakage around my pipe fittings (about one drop per hour). This indicates two things :

1. Even when running on air some oil is picked up and transmitted thorough the pipes. There is also oil slowly dripping from the exhaust pipe so the oil must be getting all the way to the cylinders/pistons.

2. I still have some air leakage around my pipes. The leakage is not just from the tube union but also the L and T fittings.

How can I best solve the air leakage ? I am first going to try some yellow plumbers tape. I also have Loctite 567 thread sealant. Are there any other possible solutions that I have not thought of ?

Edited By Brian John on 15/10/2014 06:39:23

Edited By Brian John on 15/10/2014 06:40:40

Thread: LBSC displacement lubricator
14/10/2014 06:34:24

1. How much oil do you put in a displacement lubricator ? Should the oil level be just below the steam pipe with the small hole in it ?

2. What if you overfill it and it is over the pipe...will this matter ?

3. Does any oil get through to the piston/cylinder at all when you are running on air ?

Thread: Building the twin cylinder 7BIM engine.
12/10/2014 09:32:34

1. What is the difference between the yellow and the white tapes ? They are both heat rated 100-250 degrees Celsius.

Thread: Air compressers for steam engines
12/10/2014 04:00:24

I do have a small hand held steamer for getting wrinkles out of clothes. I wonder if I can use that somehow ? It only runs for 15 minutes but I have seen people running their engines on youtube using the steam from a coffee maker !

Thread: Building the twin cylinder 7BIM engine.
12/10/2014 03:47:31

I have had another attempt at fitting the manifold : I got it closer to the cylinders (it looks more elegant this way) by using shorter vertical pipes. I also got a much tighter fit on the tube union by experimenting with slightly different lengths of horizontal pipe. I can feel no air leaking from the tube union now and I did not have to use any sealant.

It still only runs on for about 6 revolutions after turning off the compressor so I guess this is as good as it gets. I will need to build another bigger base with some cabinet handles. I did not think of that when I fitted it to this small base. It is a pity that the only timber I can buy in Cairns is pine ; a nice piece of cedar or mahogany would look better,

Sorry, I should not have deleted the earlier photos. 

1. Where can I buy some copper cups to catch the water from the exhaust ? I have seen them on youtube videos but I have no idea where to buy them.

2. Could I use (yellow) gas plumbers tape as a sealant ? It is rated for 100-250 degrees Celsius and would be a cheaper option .


Edited By Brian John on 12/10/2014 03:49:33

Edited By Brian John on 12/10/2014 03:52:29

Edited By Brian John on 12/10/2014 04:23:19

11/10/2014 14:16:24

The friction will be the same as both sides of the engine (both cylinders) were connected to the axle when I was running air through one cylinder at a time. I will see how it runs when I have put some sealant on all the pipe work. I suspect that I am getting quite a bit of leakage.

11/10/2014 13:01:42

1. The drain on the lubricator is threaded.

2. I am also puzzled about another point : before I installed the manifold connecting the two cylinders I was running the engine in by connecting the air hose to one cylinder at a time. After turning the compressor off the engine would continue to run for about 16 revolutions. But now that I have connected both cylinders the engine will only run for about 5 revolutions.

Does this indicate that I have not got both cylinders synchronised with each other or is there too much leakage around all the new pipe work ?

11/10/2014 04:12:29



I have been delayed due to a family illness but I have finally had a go at finishing this 7BIM engine by adding the manifold, displacement lubricator and a globe valve. There is still some leaking of air around the tube union on the manifold. I will have another look at this tomorrow. I may have to use some sealant (Loctite 567)

I am also puzzled why there is some air leakage from the bottom of the displacement lubricator ? Note that there is no oil in it now as I am not running it on steam yet.


Edited By Brian John on 11/10/2014 04:27:12

Thread: Air compressers for steam engines
10/10/2014 06:03:30

Has anybody tried one of these compressors for running steam engines ? I would like to know how quiet they are. My current compressor is far too noisy and gets hot after only 20 minutes.


I live in Australia but I would imagine that these are available in the UK .

I have tried aquarium pumps but they are useless.

Edited By Brian John on 10/10/2014 06:04:33

Edited By Brian John on 10/10/2014 06:04:53

Thread: Cutting, drilling and tapping bronze pipe fittings.
14/09/2014 09:58:08

Yes, I am just using a cordless screwdriver to drill the holes.

I need a washer (or something) with a small hole : this will help me to find the centre next time. I will rummage in the nuts and bolts box.

14/09/2014 04:36:55

I am in the process of fitting a displacement lubricator to my newly built 7BIM engine but I realised that I did not order enough Tee fittings on my last order to PM Research. I did have a tree casting though so I decided to give this a go. There are two Tees on the tree.


I want to end up with this :


Easier said then done ! I managed to end up with two Tees but they are not very neat so a bit of information might help next time.

1. I cut them off the tree using a Dremel tool. What would you have used ?

2. I marked the centres with a centre punch. I did it by eye but is there a more accurate way to find the centre ?

3. I then used a centre drill but I found that I was never quite in the centre ! I think my centre punch mark was slightly out but at this stage I do not think there is any way to fix this...or is there ?

4. I drilled out the fitting with a 4mm drill. Charts on the internet show this is the correct tap drill for 3/16-40 ME. I did this with a hand drill. The big problem here is holding the fitting in a vice without damaging it. I was using aluminium soft jaws but these can still squash the fitting out of shape. Any suggestions to solve this problem ?

5. I then used carbon steel taps to cut the thread : taper tap then plug second tap. Some of them turned out okay but others were not quite square. Is there a ''bodge'' to fix this once you have already cut the thread ?

I realise that practice makes perfect but the next time I do this procedure I want to get a better end result. What I have ended up with is useable but you would not take a photo of it to put in a text book !


Edited By Brian John on 14/09/2014 04:37:39

Edited By Brian John on 14/09/2014 05:03:47

Thread: Engine is binding for some reason : 7BIM engine by PM Research.
12/09/2014 18:14:27

Okay, all problems have now been solved and the 7BIM runs as nicely as the single cylinder 3BIM. Getting the piston rods set at the correct position in the cylinders is crucial on these. Loctite 222 was used on the screws passing through the connecting rods to the cranks ; other wise one side will work loose and the other side will tighten up. I also used Loctite 567 thread sealant to stop the packing nuts from working loose.

I still have to put in the manifold connecting the two cylinders and then add a displacement lubricator.

Thread: How concentrated should I make a citric acid pickle ?
12/09/2014 04:56:40

1. So you do not have to scrub the parts... you just put them in the pickle and if the solution is strong enough then they will come up shiny ?

2. Yes, I was wondering about white vinegar too ? It would be much safer and easier to obtain than sulphuric acid and much easier to use than citric acid.

Edited By Brian John on 12/09/2014 04:57:15

Thread: Making Piston Rings
11/09/2014 18:12:24

What about Delrin or some of the other modern plastics ? They would be less likely to break upon fitting.

Edited By Brian John on 11/09/2014 18:12:53

Thread: Piston rings or graphite packing ?
11/09/2014 18:07:34

What do you make piston rings out of ?

11/09/2014 13:48:08

1. Is it possible to make your own piston rings ?

2. How necessary are they ? What if you did not use any rings or Teflon packing at all ?

Thread: How concentrated should I make a citric acid pickle ?
11/09/2014 10:53:56

I will be having a go at hard soldering a small boiler soon. I have bought some citric acid from the supermarket (75 grams). How concentrated should I make the pickle to neutralise the flux ?

Thread: Does anybody own a Proxxon FD 150/E lathe ?
10/09/2014 13:54:18

The second damaged Sieg C0 was sent back today so I am still looking for a small lathe. Does anybody own a Proxxon FD 150/E ? It has a 55mm swing. Does this mean the maximum flywheel it can turn is 55mm or 110 mm ? Is there a face plate that can be bought to go with this lathe ? It does not look like it but I find that unusual.


I think this will be too small for building stationary steam engines but I am running out of options.

NOTE : I live in Australia

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