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[ir3]

I read most of the threads on setting up the Cheddar Proteus Steam Engine and there is a lot I still need to learn. My current problem is the Engine runs on compressed air. When running under steam the engine locks up solid. I can't turn the flywheel by hand. Here is what I have observed. With the cylinder covers off when one piston is at or near to TDC the other piston is not at or near BDC. When I first received the engine, one of the screws on the pushrod was loose. Is it possible that piston has moved causing the difference.


So, how I make sure the pistons are timed properly. Can I make an adjustment with the cylinder covers off. If I can make an adjustment, do I need to reset the port timing.


Thanks in advance.

[rhavrane]

Bonjour,

I have had a problem like yours.

The cylinder head fit was too tight, as soon as water/steam was coming, the machine was locked (close to your case ?). I solved the problem by changing the existing gasket for a thicker one.

How did I identify this problem ? By looking if blocking occurred on a top / down dead center on each cylinder which are wedged at 90° so can't block on a dead center at the same time.

Then by removing the cylinder heads bolts and putting a finger on them to feel any vertical movement even slight.

I have't been obliged to adjust the timing as I didn't force the machine to run.

I hope this will help you.

[captain_reg]

If it works on air I wouldn't expect it to be a timing issue. If you run on steam and it locks, does it then free itself when it cools? I have a cheddar plover than until recently wouldn't run on steam as the throttle valve kept getting stuck so a servo couldn't move it. Nothing I tried help but speaking to Jerry from Cleavedon steam at the Blackpool show he suggested drilling out the pivot hole from 4mm to 4.1mm. As if by magic the issue was solved and had been due to thermal expansion all along.

[ir3]

Raphael, I did loosen the screws on the cylinder caps and did not notice any lifting or movement, so I believe that the clearance is probably in spec.


This engine locks with the first application of steam. I opened the throttle valve slightly to limit the amount of steam, but the engine did not move. If it did actually move, it was probably around a half revolution. With the engine cold, what I am finding now is the crankshaft rotates a bit more than 180 and then locks. If I move the reverse lever to the opposite side, the same thing happens when I rotate the crankshaft the other way, a bit over 180 then locks. The two connecting rods are not quite in the same position when it happens. One is perfectly vertical for one piston which could be a TDC or BDC. The other connecting rod is slightly off vertical. This seems to be correct, so I do not understand why I can't rotate it by hand more than 180+ degrees. I'll keep trying to solve this but it is a mystery.

[DBS88]

The proteus engine can be difficult to start under steam, all three of the proteus engines I have used exhibit this behavior, I found the best way to operate them was to partially open the steam valve at a low pressure and warm the engine and turn the prop to rotate the engine. Then as the boiler pressure rises get the engine running, this seems to avoid locking the engine with condensate water. If you wait until the boiler is at pressure let’s say 4 bar and then try to start the engine from cold, that is when it locks. Once the engine is warm and has run there is no problem stopping and starting them it’s just the initial start from cold. These engines are fairly tight when new and take a bit of running in, so if your engine has not run much it will improve the more you run it. Hope this helps

[KBIO]

Hello !
This is right ! The steam have to travels a narrow path : 2 mm through the reverse valve and  through a solid piece of cold brass . The vacuum created when the boiler's valve is opened carries a lot of water with the steam, and the large amount of condensation added due to the cold temperature of the metal causes water lock. In all cases, it is necessary to help the motor evacuate condensation by turning the propeller by hand .
Afterwards, it's a pleasure to let these magnificent machines run. Also , keep in mind that the piston's O'ring does not allow the fluid to pass from one side to the other.
The timing is very tricky and it has to be perfect with the Maudlay gears. Apart from one I bought from a guy who put his. nose in it and which needed to be fixed , I never seen any problem with this kind of engine which is very, very reliable.
Let us know your progress and enjoy it .
Kind regards.

[1967Brutus]

Best way to get ANY steam engine running on cold start-up under steam, is to only open the steam throttle slightly, and keep rocking the reversing gear back and forth until it turns over. By rocking back and forth the reversing gear, you alternate opening the inlet and exhaust to the same working chamber even if the engine is not turning over. This will expell water and preheat the engine. Once water escapes, this will allow the piston to move a teeny tiny bit, and slowly the engine wil gain freedom of movement, until it turns over completely.

Give the engine, once running, 30 to 60 seconds of running low to medium RPM to warm through.
After that, it should run freely, start, stop and reverse at will.
My engine (Microcosm M29) is only about 6 cc, but on start-up it will invariably produce about 20 ml of condensate, even when the engine is turned over by hand prior to starting it up. It still refuses to start up under its own power when cold, but it WILL start up under own power 100% of times, when the reversal gear is being rocked.
This means, that the condensate was NOT in the engine befor start-up, it is being formed during start up by the steam condensing against the cold metal.

My engine, once warmed through, sometimes needs one or two quick reversals to restart if the engine has been stopped for more than 30 seconds when under steam: The inevitable small amount of steam passing the closed throttle will condense in the engine and hydrolock it. It is a common issue for steam engines big and small, it is why full size steam engines usually have blow down valves on the cylinders. Rocking the reversal does the same in a different way.


Some engines perhaps are more sensitive to it than others, but ALL steam engines do it to a more or lesser extent.

[KNO3]

I've had a similar problem with an engine (Hemmens single cylinder) that ran great on air and locked up on steam. It turned out the piston o-ring would swell when in  contact with hot steam and lock the piston. A change of o-ring solved the problem.

[ir3]

Thanks for all the input, much appreciated. The problem with the engine was partly my stupidity. While cleaning the engine I decided to clean up the forward/reverse gears and not realizing what I had done, the engine timing was thrown way off. With the help of Dave S. and Jerry of Clevedon Steam, the timing for the engine has been corrected and the engine runs very smoothly with about 50PSI from the boiler. The next problem to solve is that while the engine is running the boiler is having problems maintaining pressure. The pressure drops to about 30PSI and the engine stops. Could also be the burner or the gas supply. Or possibly the gauge is faulty and showing the boiler is up to pressure when it is actually lower. The Steam Plant has been sitting idle for many years. So, several things to look at. At least, the engine is timed.

[KNO3]

That's good news. Now you need to sort out the boiler.

[DBS88]

I am glad to hear that  the Proteus Engine has been saved, after all its such a masterpiece of steam engineering and sounds glorious when it's running fast.
Can we assume that you are using the Cheddar Proteus Boiler? If so, its a number 8 Gas Jet, make sure it's clean unblocked, I use a bit of fuse wire. Next the setting of the gas jet is crucial, the dimension suggested in the instructions is correct, I use a piece of copper pipe of the right size, I put it through the primary air holes and then rest the gas jet against the pipe and tighten the screw to lock the gas jet holder in place, then remove the pipe section used to set the spacing. Getting this spacing right makes a big difference to how the boiler performs.
I have two of these boilers, one supplying two puffin engines and one supplying proteus engine, in both cases, the boiler keeps up with demand whilst the engines are running fast. In my Bustler Tug with the Proteus it will run fast for an hour maintaining the boiler pressure at 5 Bar whilst being filled with water from the pump to keep the water level up. The best water level for this boiler is about 2/3 full, if you fill it too much you will have problems similar to those you describe. hope this helps

[DBS88]

having received a message about this I thought it best to clarify, my experience is with the Horizontal version of the Proteus boiler, here are my two tugs with Proteus Horizontal Boilers complete with automatic boiler controls (ABC) systems, one is by Cheddar, the other is the new and improved version from Dénes Designs

[ir3]

The gas jet needed cleaning and now the boiler gets to 4 Bar. At this pressure, the engine ran great for a short time. The pressure didn't drop very much when the engine is running. However, there is a lot of water in the condensation tank. Not sure why. Do I need to wait longer before opening the throttle valve on the engine?

[DBS88]

Great news that the engine is running well and that the boilers performance is improved, what's stopping the boiler pressure from getting higher? Is the safety valve lifting, or is the burner not heating the boiler anymore? Is there an automatic boiler control system or gas attenuator operating?
The boiler and engine are rated with a working pressure of 6 Bar, that said it should perform perfectly at 4 Bar as can be seen from my Bustler Tug which when that photo was taken was set at 4 Bar, didn't see the need for more power after that test run.
Re the condensate, initially there will be quite a bit, so what most people do is to warm the engine and get it running smoothly, then empty the condensate tank, then run the engine, then empty the tank again at the end of the run.
As a thought, does your set up use a coil of steam pipe from the steam dome to entering the chimney to dry/heat the steam further before it enters the engine? The standard set up from Cheddar used a pipe in this way, it improves performance and reduces the condensate produced.

[ir3]

I plan on doing a full boiler test to make sure the safety aspects are working. The pressure sensor will need calibration. There is a pot on the ABC module for setting the threshold. At this time, I have no idea what pressure will activate the pressure sensor for the ABC. The instructions do not appear to indicate a starting point, so I am going to center the pot and let the boiler run until the pressure sensor causes the ABC to shut off the main gas valve. Not so sure I want to run the boiler at 6 Bar, so I am shooting for 5 Bar for now. Once I am pretty sure the boiler is performing properly, I should have a good working, very powerful, Proteus Steam Plant. More to follow.

[ir3]

The boiler tests this morning worked out very nicely. At 60PSI, the safety valve just started opening. I was able to adjust the Pressure sensor so that the gas valve shuts off the main supply but keeps the pilot lit. As the pressure drops, the gas valve opens back up. I am pretty confident that the boiler safety valve is working properly, and the gas control valve servo control is also working. I am happy with 60PSI at the moment and if in the future more pressure is needed, the safety valve can be adjusted and the gas control valve can be reset to a higher value. There are some steam leaks in the lines to the engine and the engine itself. That should be the last step in the process.


Thanks for all the help. My past experience has always been following the instructions to operate a Steam Plant and never having to solve some of the problems this plant exhibited. A great learning experience.

[KNO3]

That's great! How about doing a video of the Proteus on steam?

[1967Brutus]

Thanks for all the input, much appreciated. The problem with the engine was partly my stupidity. While cleaning the engine I decided to clean up the forward/reverse gears and not realizing what I had done, the engine timing was thrown way off. With the help of Dave S. and Jerry of Clevedon Steam, the timing for the engine has been corrected and the engine runs very smoothly with about 50PSI from the boiler. The next problem to solve is that while the engine is running the boiler is having problems maintaining pressure. The pressure drops to about 30PSI and the engine stops. Could also be the burner or the gas supply. Or possibly the gauge is faulty and showing the boiler is up to pressure when it is actually lower. The Steam Plant has been sitting idle for many years. So, several things to look at. At least, the engine is timed.

Could be me, but... An engine stopping at 30 psi does not seem right to me? That's 2 bar, a lot of engines have that as normal operating pressure.

I do not have a Proteus, but my engine keeps running down to about 5 psi or maybe even a touch lower, and I would expect most engines to behave like that?

[DBS88]

The Proteus engine is notorious for being tight until they have had some significant run time and from the three I have run, they have definitely needed a healthy amount of pressure to run them, once bedded in the starting and running pressure improves. Here’s a video of one of mine running, I am testing the replacement sight glass sensor from Dènes Designs in the video you will see the valves operating and the pump pumping https://youtu.be/iLoyLBfm9dg?si=reZqMmdDhMHLEXiF

[ir3]

Thanks for all the comments and pictures. They are great help. I've been away from the shop for a few days and now back on it. The boiler pressure sensor was replaced, and it now switches very nicely at 60 PSI. The safety valve opens at a bit over 60 PSI. There are no other visible problems with the boiler so now on to the steam engine. There were a few steam leaks around the cylinder covers and the slide valve covers. There was also a leak at the throttle box where the copper tubes seat. There is also some leakage around the shafts of the steam valves both on the boiler and engine. Waiting for new O-rings. Back when I mentioned the engine wouldn't run when the pressure dropped to under 30 PSI, it was before I got the timing right. Once everything is back together, more extensive testing will be done.

[DBS88]

Thank you for the update, its great to hear about the positive progress, looking forward to seeing and hearing your Proteus engine running on steam.

[ir3]

It's been a while. I am still struggling with the setup of the steam plant. There are a lot of steam leaks around valves and the engine itself. I finally got some O-rings for the steam valves and that is no longer a problem. Most of the steam leaks at on the engine have been dealt with. I am being plagued with one little problem after another. The steam pressure/temperature sensor has been giving me some problems. Originally when troubleshooting this sensor, I disassembled it. I tried a replacement, but I could not get it adjusted to work with the ABC, so I tried the original sensor again. I seem to be able to get it open and close the gas valve at around the 60PSI, so I am assuming I did not damage it when I inadvertently disassembled it. I am not going to worry about the sensor for now. It seems to work. The next problem that popped up is that after filling the fuel tank, the burner would run for a few seconds and then just go out. This is with the gas valve fully open. This problem turned out to be a problem with the filler nozzle that screws onto the gas cannister. Changed that and can now get the fuel tank filled. Lots of little headaches build up into one large one.


So now the fuel tank fills properly, and the boiler seems to be doing just fine. The pressure sensor causes the gas valve to close when the pressure gets too high and as the pressure starts to come down, the valve opens. I am happy with this part of the ABC. There are still some major problems that I just do not understand. There has been some discussion about this, but I am at a dead end. First, when I open the steam valve to the engine, the engine starts up very nicely and I can get very high RPM, so I am confident that the timing in the engine is good. The problem is the boiler pressure starts to drop and within about 30 seconds the motor comes to a complete stop. I originally set the water level in the boiler to about 2/3 of the sight glass. When the engine stops running due to the pressure drop, the water level has dropped to about 1/3 of the sight glass. While running, the steam that is coming out of the condenser appears to be quite dry, no bubbles and no apparent moisture at the stack. But the amount of water that is coming from the engine exhaust into the condenser is huge. I would guess, almost the same amount of water the boiler lost during the run.


I can stop the minor steam leaks in the engine, but I cannot understand the problem with the boiler and why the superheater is not drying out the steam going to the engine. I have no idea the history of this steam plant. I purchased it back around 2010 but never ran it on steam. I used compressed air on the engine just to see if it would turn. About 5 years later, I decided to part with the steam plant. I contacted the buyer last year and purchased it back. He indicated that having another he would just display this one. So, the bottom line is that there is no history of this steam plant before 2010. The only conclusion is that the boiler has problems, but I have no way of knowing.


I completed the MHB Project X but have not put it in the water as of yet. I followed the instructions to fire up the boiler and ran the steam plant with no problems.


I am near the end of dealing with Proteus Steam Plant, so if someone has any suggestions as to how I can deal with the boiler, please let me know. I know there is has been a lot of discussion on this thread about the boiler problem, but nothing works.


Thanks for all the inputs.

[KNO3]

Hello, it is hard to say what's wrong without seeing it. It could be boiler priming, which happens when the boiler has certain impurities inside and instead of producing steam, the water foams and the boiler expels both steam and water. Or maybe something entirely different.

Some pictures, or even better a video would be useful to find the problem.

[DBS88]

Re the boiler, assuming it is actually the Proteus Boiler? It is a very good boiler that has no problem providing sufficient steam for a fast running proteus even while the boiler is being filled with water from the pump.
Suggest going back to basics, check the burner is positioned in the flue in accordance with the instructions (basically pushed in until the radius of the burners back plate is in line with the edge of the boilers flue, then check and clean the gas jet, which should be a No8. Position the gas jet in the holder as per the instructions which is 4.5mm from the end of the gas jet to the lower edge of the primary air holes in the burners mixing tube.
Once set up like this, run the boiler and engine without the ABC turned on to check that works properly, if its OK, turn on the ABC and check that its controlling the gas supply and hence the boiler pressure as you want it to. If its not a dirty gas jet causing the issue, I suspect that the gas valve is not opening sufficiently to achieve a full flame at the burner.

[DocMartin]

Some pictures, or even better a video would be useful to find the problem.

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