Mery Explosive Engine

[Chipmaster]

Hi Graham, is this arrangement what you're suggesting?

IMG_2915 by Andy, on Flickr

Unfortunately it was too cold for me to stay in my garage this afternoon. I'll give it a go tomorrow when my gas heater has raised the temperature.

Andy

[Alyn Foundry]

Yes, that’s perfect.   

You should be able to finely control the mixture via the control knob. I’d suggest using the motor to drive the engine whilst performing the adjustments.

   Graham.

[Chipmaster]

My Mery Explosive ran for the first time this afternoon after revising the gas supply and retarding the ignition.

<a href="https://www.youtube.com/watch?v=U449tYGyxF8" target="_blank">http://www.youtube.com/watch?v=U449tYGyxF8</a>

It was running too fast and soon loosened the clamps holding it down so I had to stop it. The smoky exhaust is due to the cylinder lubrication oil that has accumulated over a period of attempts to get it running.   
I think retarding the ignition still further will stop the knocking which sounded like pinking. Setting up a cooling system and a fair amount of fine tuning will follow.

Andy

[Jo]

 

Jo

[Chipmaster]

Hi Jo,

I was very surprised when it suddenly started after so many failed attempts 

Andy

[Alyn Foundry]

Congratulations Andy….

Another thoroughbred to add to your ever growing Stable.

   Graham.

[Dave Otto]

Congrats!

Dave

[cnr6400]

  she's a runner! 

[Sanjay F]

Brilliant, well done, looks great, what a fabulous achievement

[Chipmaster]

Thanks chaps, to be continued….

Andy

[Roger B]

Congratulations on the first run     

Looks and sounds great 

[propforward]

Lovely engine - I know from speaking to a few builders of this engine, including Gary Martin, that these are very sensitive engines and not an easy accomplishment, so very well done indeed.

[Twizseven]

Well done Andy. A complicated engine well executed.

 

Colin

[Chipmaster]

Thanks for the comments Roger, Colin and Stuart - sensitive engine yes indeed it is. I haven't been able to get it to run since those videos posted on YouTube. I have tested the output from my propane regulator with a manometer and found it's really erratic at it's lowest settings. Searching around the internet it seems regulators with low pressure outputs such as 2" water column / 0.07 pounds per square inch or 5 millibar are very expensive.

So, I'll set the regulator at it's lowest consistent setting (1/2 psi) and rely on the needle valve in the engine's mixer to get the mixture right.
Naturally any suggestions gratefully received 
Andy   

[MJM460]

Hi Andy, well done on getting the engine running.  I am sure you will sort out the fuel issue.

I am not sure what your fuel set up includes, but have you tried reducing the propane fuel pressure in two stages.

If you have a regulator set at something around 3 to 7 psi, 0.3 to 0.5 bar, the second regulator with the lower inlet pressure will have to open further and will usually be more reliable that way.

Reducing the full propane pressure to the required engine inlet pressure in one step requires the regulator to operate very nearly closed, and even very expensive large diaphragm industrial regulators work better in two stages.

I hope that helps.

MJM460