OPOC Engine

[75Plus]

This video has been around since 2008 but I could not find any reference to it on the site so I am posting it.

The capabilities of this engine, if proven, are mind boggling. 325 HP from 2 cylinders with 4 pistons. Funny thing, I have often thought of an engine similar to this, 2 pistons in one cylinder, but never considered it as a 2 cycle, turbo charged, diesel.

http://www.engineeringtv.com/video/Opposed-Piston-Opposed-Cylinder

Joe

[Bluechip]

Joe

Very interesting configuration, I wonder what the balance is like ??

Many other manufacturers have done the 2 pistons/ one cylinder concept though.

Here's 6 pistons in three cylinders .. and IIRC Junkers did a very slim aircraft diesel engine with the principle.

Would have to do a search for that one .. I may be wrong .. circa 1930's I think ..

http://en.wikipedia.org/wiki/Napier_Deltic

BC

EDIT  Oops, brain fart yet again... It looks like the Wiki link refers to the Junkers engine ... 

[John Stevenson]

Commer built one for their trucks, 3 cylinder, 6 pistons, finished up at 3.53 Litres and 150 BHP

http://www.sa.hillman.org.au/TS3.htm

For some reason Wikipedia and this site are quoting the earlier engine.

Fitted in a 4 wheeler rated at 14 tons they would do 19 mpg, try asking someone with a 3.8 Jag to load 14 ton on the arse and get 19 to the gallon 

John S.

[75Plus]

Very interesting configuration, I wonder what the balance is like ??

BC

According to the designer balance is not a problem as the crankshaft is pushing one piston while pulling the other in each cylinder and the cylinders are 180 degrees out of phase.

Joe

[Bernd]

This looks like a redesign of the Fairbanks-Morse diesel engine used in subs and railroad locomotives. They were two cycle opposed piston engines. I believe they had two crankshafts though.

Bernd

Edit: Just did a quick Wiki check. Nice cut away veiw of that engine. Here's the LINK.

[Bogstandard]

It definitely looks like another case of not something totally new, but an old design brought up to date, most probably by new machining methods and materials.

I always wonder at how many 'new inventions' are just rediscoveries, made possible by new techniques. A lot of the old designs and patents never got off the ground purely because they could not realistically be produced at the time.


Bogs

[Bluechip]

Commer built one for their trucks, 3 cylinder, 6 pistons, finished up at 3.53 Litres and 150 BHP

http://www.sa.hillman.org.au/TS3.htm

For some reason Wikipedia and this site are quoting the earlier engine.

Fitted in a 4 wheeler rated at 14 tons they would do 19 mpg, try asking someone with a 3.8 Jag to load 14 ton on the arse and get 19 to the gallon 

John S.

That's interesting John .. didn't know they were built like that ... 

I can remember the trucks ... quite nippy off load and hideously noisy ... but not quite as bad as a de-baffled FS1E

BC

[doubleboost]

De baffled FS1E
Them were the days
At least mine had a bit of port work done as well

[John Stevenson]

That's interesting John .. didn't know they were built like that ...  

I can remember the trucks ... quite nippy off load and hideously noisy ... but not quite as bad as a de-baffled FS1E

BC

Ever heard one without the silencer(s) ?

We had a phone call one day to say one was coming in later on that same day and had lost the rearmost silencer, could we get one in ready ?

About 4:00pm as we were sat down having afternoon snap, we heard this truck starting off from the lights on the A52 and start pulling up the hill.

This was about 3/4 of a mile away   and he's only lost the one silencer.

DKW used to race a split twin supercharged two stroke in the pre WWII TT races in the Isle of Man, you could hear these on the Lancashire mainland when they were going full chat down Bray Hill and that's 40 miles away.

[BillTodd]

Just like a Doxford standing on a mirror

long thread:
http://www.practicalmachinist.com/vb/antique-machinery-history/photos-big-machining-processes-doxford-sons-c1950s-181722/index5.html#post1137038

[Bluechip]

That's interesting John .. didn't know they were built like that ...  

I can remember the trucks ... quite nippy off load and hideously noisy ... but not quite as bad as a de-baffled FS1E

BC

Ever heard one without the silencer(s) ?

We had a phone call one day to say one was coming in later on that same day and had lost the rearmost silencer, could we get one in ready ?

About 4:00pm as we were sat down having afternoon snap, we heard this truck starting off from the lights on the A52 and start pulling up the hill.

This was about 3/4 of a mile away   and he's only lost the one silencer.

DKW used to race a split twin supercharged two stroke in the pre WWII TT races in the Isle of Man, you could hear these on the Lancashire mainland when they were going full chat down Bray Hill and that's 40 miles away.

JS

Nope, never heard one without silencer, must have been apocalyptic .. once near a ( Capri 80cc ? ) scooter on open port, ears ringing for hours.
Got a DVD from a recorded Ch4 long ago with the Deek on it. Timothy Spall narrated series .. IIRC

John DB .. You had a Fizzy? .. I admire your heroism. Not the sort of thing I would admit to on an open Forum >> 

Back to Joe, and apologies for ambushing his thread, but I'm sure Mr. J. S. will  send a compensatory cheque ... 

When you look at the concept, it is well suited to a 2-stroke cycle. With the pistons meeting ( or hopefully very nearly ) in the middle, you would achieve complete scavenging of the spent charge. Always a source of grief for the conventional 2-S, if you look at all the wierd things like deflector pistons, auxiliary valves etc. that were prevalent in their early days.

BC

[doubleboost]

&feature=related
I wish i still had my FS1E now they make good money

[John Stevenson]

They were a good engine for the day but unfortunately they got an undeserved bad reputation for blowing up because they asked too much of them.
They finished up putting these in multi wheelers plated at 26 tonnes, imagine that 26 tonnes from 3 1/2 litres.

Another fault was they were brilliant starters, basically one compression and they were away, trouble was the driver would press the button a quick stab and it would fire but occasionally if it didn't it would bounce back and could start up in reverse. Once running in reverse the governors didn't work, going the wrong way for centrifugal force to throw in so it went to full chat plus a bit more.

That had a knock on effect of causes a crankcase vacuum and it started to suck oil up from the sump and burn this. Add together high revs, over speeding and lack of oil and it was a disaster waiting to happen. What usually happened was that before it had chance to seize it would get all egg bound and throw the rocker shafts out the side of the engine.

You couldn't stall one, just too much power plus all the exhaust was now coming out the air intake and filling the cab up prompting the driver to run away 

We had one in one day for service and struck it up and it went backwards, our boss who had a lot of experience with these calmly got a fire extinguisher and let it go straight up the exhaust pipe and it died out.

To get back to the OP (sorry  ) did anyone notice the electrically assisted turbo's ? These type of engines can't start without some for of boost hence the supercharger on the original.

A lot of these engines finished up in universities where they studied them to get even more power out of them, they started off using a supercharger driver off the engine and the engine drove a turbocharger where at some stage the supercharger was disconnected as it takes a lot of power to drive one.

That extra power then cause the exhaust gas volume and temp to rise and it was a spiral.

In the end they were taking the power output off the turbocharger shaft thru differential gearing and getting more power by just using the engines as a gas generator.

If you can get a copy (very expensive now ) see L J K Setright's Some Unusual Engines.

John S.

[Swarfing]

I have to ask was the Wankel engine a variation on a theme of this? and whilst i'm at it the FS1E was only good for being whooped by the earlier AP with the polo removed from exhaust port 

[Bluechip]

I have to ask was the Wankel engine a variation on a theme of this? and whilst i'm at it the FS1E was only good for being whooped by the earlier AP with the polo removed from exhaust port 

Not clued up on blowers, in fact I know virtually nowt about them, but it may be one of these :

http://en.wikipedia.org/wiki/Roots_type_supercharger

Not too clear from the vid.

Can't see any real similarity to a Wankel engine, apart from lobes whizzing around in an enclosed space.

( Wish I'd never mentioned Fizzies now, no idea this board was populated by so many deviants ..  )

BC

[lordedmond]

Commer built one for their trucks, 3 cylinder, 6 pistons, finished up at 3.53 Litres and 150 BHP

http://www.sa.hillman.org.au/TS3.htm

For some reason Wikipedia and this site are quoting the earlier engine.

Fitted in a 4 wheeler rated at 14 tons they would do 19 mpg, try asking someone with a 3.8 Jag to load 14 ton on the arse and get 19 to the gallon 

John S.

Yep they had quite a few at Stanton ,boy they did scream still hear them now, had the fortune to see many stripped down in lorry garage ( I was a Sparks at the Iron works ) so got to go to all depts to fix things

Regards Stuart From Ilson