• If you like what you see here and your interests are compatible with our 30,000 other users, Welcome. Fill out the registration form with your interests, your real name (seen only by moderators) and your city, state or country. Be certain that you have spelled your email address correctly! Your account is then manually checked and approved.

Engine Identification Wanted


Here are a few photos of a combination engine and compressor in one. The engine has an overhead pushrod operated exhaust valve and atmospheric inlet valve. The compressor has an atmospheric inlet valve. The only ID is a small brass plate headed MWS&DB, (Metropolitan Water, Sewage and Drainage Board), the precursor to what is now known as Sydney Water. There may have been another plate on the side of the engine and it would be good to identify it.
It is a most interesting unit, and needs to be saved from scrap.


peter coleman

Re: Engine identification wanted

Hi it looks like a Ruston to me. Used for air starting a larger Ruston engine

---------- Post added at 03:59:35 AM ---------- Previous post was at 03:55:06 AM ----------

I wish it was a bit closer to me need one for air starting a 6 cylinder blackstone

bull dog

Hi, The engine is indeed a Ruston & Hornsby, a 6PS compressor engine, which as the other replies have stated it would have been used to charge the air vessel(s) used for starting a large oil engine.
Patrick UK.


Re: Engine identification wanted

Looks like a Ruston air compressor engine. I have one in good nick.
Ray, could you post a photo of yours, please.
Thanks to all who have replied. I will try and save it, though I have no interest in it myself.

Scotty 2

Hello all
I learn so much from these unidentified engine sorts of threads.
I've never heard of this engine....but now I have. It looks interesting to say the least.
I also learnt that they made a few different sizes of compressor engine. Another is the 2 PS
Anyways here's a video of one running.
Cheers Scott



Many of Ruston & Hornsby's cable excavators (sold as Ruston Bucyrus) were started via one of these onboard 6PS units plumbed into the cooling system of the main engine.

---------- Post added at 11:53 ---------- Previous post was at 11:48 ----------

I have one of these for starting my Ruston 3VQBN engine from a 19-RB cable excavator (shovel). Not exactly a portable display, as the pair weigh around 3 tonnes. Regards,