Two-stroke Engines + Over-the-top-tech + More - Morley 401

By: Dave Morley

Presented by

bentley display bentley display

Morley gets creeped by uppity machines, finds most new-tech nonsense and reminisces about Commer Knockers

From Unique Cars #401, May 2017 

Morley's Workshop

Techin' it too far

Has it ever occurred to you that maybe machines are getting a bit uppity? I can live with a fridge that makes its own ice-cubes, but I don’t think I want one of those bluetooth-connected jobs that `knows’ when you’re low on milk or cheese and orders another cow’s-worth for you while you’re at work. There’s just something a bit creepy about that, and yet it’s technology that has existed for some time now. Apparently, the fridge scans the barcodes of whatever you place in it so it knows what to reorder. Though how it can tell when the milk is off without having a sniff of it, I don’t know.

Anyway, while the old bangers you’ll see in Unique Cars are my first automotive love, I also work for other car books, most of which have a younger clientele and much younger subject matter. And some of the new tech I’m seeing on new cars has me a bit worried.

I drove a new Bentley the other day; one that featured technology called lane-assist. Because the power-steering now operates off an electric motor (as does the vast majority of the world’s power-steering these days) the Bentley was able to talk to the electric motor and adjust the steering all on its own. That’s how those fancy self-parking systems work. But with cameras and radar for eyes, the Bentley was also able to `see’ an unbroken white line on the road and move the tiller to keep itself within those lines.

The problem was that the Bentley was a huge great lump of a thing and didn’t, in all circumstances, fit within the white lines. So even though I wasn’t trying to change lanes, at various times I got close to the line. Too close for the Bentley’s comfort, it seems, and it would try to steer me back on to the straight and narrow. I won’t say the wheel was fighting me, because it was a gentle nudge from the car at best, but it was definitely off-putting. And because not all roads have clearly marked white lines and because the Bentley’s eyes are not infallible, sometimes the car would let you fall completely off the road without mentioning it. Clearly, this is not a hands-off system and remains one of the big problems with the autonomous-car concept we keep hearing all about.

Engine -stop -start

But the piece of new-tech I dislike most is stop-start. Okay, I can see how switching the engine off at the traffic lights can save fuel. But when a modern, small-capacity four-cylinder hatchback is using about 0.3 of a litre per hour when idling, it aint gonna save much. And then, when the light goes green and you step on it, the motor springs into life and away you go. So what’s not to like? Plenty.

For starters, there’s lots of NVH going on when the things cranks into life. It’s worse if it’s a diesel. But there’s also sometimes a bit of a delay (some systems are better than others) as the car cranks and starts and THEN moves away. Okay, it’s split-second stuff, but I’m the sort of bloke who times his run into a traffic flow with a fair degree of precision. Also, when I commit to hauling into a moving stream of cars, motorbikes and B-doubles, I want to know the engine is already running and isn’t going to cough or splutter or stall. And I just don’t feel confident if the thing isn’t already whirring away smoothly beneath me.

But what I hate most about these systems absolutely haunts the mechanical sympathist in me. When the light goes green and I step on the gas, the engine fires and then goes from zero load to a big load, way before it’s had time to build up oil pressure. Yes, I know there’s still oil in the bearing shells (The engine only stopped a minute ago, remember) but pressure? Not enough for my liking. I tried it yesterday on a modern car I was driving (okay, a Porsche 911 Turbo) which had both an analogue and a digital oil-pressure gauge. And I have to say, I was already moving pretty well before either gauge was registering a normal amount of pressure. And that’s on a brand-new car with a high-tech variable-displacement oil pump. What about a not-so-special car with an engine showing a bit of internal wear?

What do you think? Am I striking a chord here or am I my usual barking mad self, hell-bent on wasting 0.3 litres of fuel per hour?


Brands Meanz Banz

Datsun -240z

I was talking to a mate the other day who reckoned he just couldn’t bring himself to allow a Holden into his Ford-dominated garage. What, I asked, not even a GTS 327 Monaro? Or an A9X? Nope, he said, couldn’t do it. This is just plain dumb. Brand loyalty is over-rated. And by the way, when was the last time a big corporation did something warm and fuzzy for you? Exactly. The problem with being dogmatic like this is that you’ll miss out on some really good stuff, purely because it has the `wrong’ badge on it. I’d like to know how many people would have bought, say, a Datsun 240Z back in the day, but couldn’t get over the fact that it was (and excuse the outdated expression) Jap Crap. Seen what a clean 240Z is worth today?

So here’s my tip: Don’t let your preferences become prejudices.


Here come the Knockers 


Allow me to share with you some details on the Commer "Knocker". The TS3 Knocker utilised a single crankshaft which had two crankpins 180 degrees apart for each cylinder and both the air piston and the exhaust piston were connected to the crank pins via connecting rods and rockers, such that the TS3, three-cylinder had the following:
• One crankshaft with
6 crankpins;
• Twelve connecting rods;
• Six pistons;
• Six rockers.

The initial TS3 engine produced 105BHP at 2400 rpm and this was increased to 117 BHP during the early years, all from a 3.26 litre (200 cubic-inch) block, making the output per litre comparable to the 15-litre-plus turbocharged engines in current Kenworths, Scanias and Volvos!

The reliability of the Commer Knocker in the livestock transport area in the 1950s and 60s was well regarded, as the relatively uniform engine speeds and long running times did not produce the blower quill failures nor the de-coking requirements that city-usage trucks or those operated in their home country (UK) seemed to endure.

What was important to longevity was clean and unrestricted incoming air and the Rootes Group addressed this by fitting Australian Knockers with dual oil-bath air-cleaners. Incidentally, this requirement for clean air was not lost on Chamberlain Tractors which fitted a GM 371, two-stroke engine to its large tractors produced in WA at around this time, and fitted very large oil-bath air cleaners and, in some conditions, specified twin air-cleaners. 

The Rootes group was taken over by Chrysler in 1964 which promptly killed off the TS4 engine which was to be the replacement for the TS3 model, and reputably addressed most of the perceived short comings of the TS3 engine. Unfortunately for it, it was not made in the USA.

Ts 3-flat -configurationThe TS3's distinctive flat configuration led to some calling it 'the suitcase' motor

As a schoolboy at Casterton High in the late 50s and early 60s we were often presented with the spectacle of a line of Commer Knocker livestock transports, nose-to-tail, negotiating the long climb from the town centre on livestock sale days. The sound of four or so Knockers in second gear at 10 to 15km/h climbing the long hill was ear shattering. Occasionally we were treated to the sight of the lead truck wheelstanding for 200 or 300 metres with the front wheels 30 to 40cm off the ground, the driver reducing throttle and grounding the truck as he approached the turn in the road at the top of the hill so as to have steering.

Mostly these trucks belonged to Scotts Transport based in Mount Gambier, and today this family company has in excess of 700 trucks on the road and, in addition to covering all aspects of transport, has a number of large pastoral properties throughout Australia. Local folklore suggests that the Commer Knocker set them on the path to success.

It has been close to 50 years since a Commer Knocker was used in commercial transport, but all is not lost. Achates Power Inc, established in 2004 in the US, has redesigned the opposed-piston two-stroke diesel utilising two crankshafts geared together, an array of current technologies and metallurgy. They now have multiple contracts with the US military and have demonstrated that the performance, economy and cost of their engines is superior to current offerings and they already comply with Euro 6 emissions.

The acceptance into high volume production for passenger cars and light trucks in the US is facing headwinds from low gasoline prices of USD $2 per gallon (USD 50 cents per litre) negativity brought about by VW’s "dieselgate", and overall concern about the carcinogenic attributes of diesel particulate emissions.  We could however see them in large trucks again, but I suspect with muted exhausts.



Commer -2The Le Mans-winning Ecurie Ecosse team's upmarket transporter was 'Commer-Koncker' powered

The more I learn about these incredible engines, the more intrigued I become. And so do you lot, apparently, because two-stroke diesels in general and Commer Knockers in particular are the topic of the month around here. The Commer used a truly amazing design, and I’d love to sit down for a chat with the bloke that came up with the idea of a supercharged, opposed piston two-stroke in the first place.

It’s funny you mention Chamberlain Tractors, too, because the Chamberlain brothers also had a crack at a blown two-stroke way back in (I think) 1929. Admittedly, it was a petrol engine and it was used in an open-wheeler race car. And while it was fast and led the Australian Grand Prix back in the day, it proved to be a bit fragile to be too handy at long events. It made its name, therefore, as a hillclimb and sprint racer and was a bit of a legend at the Rob Roy hillclimb outside Melbourne. From what I can recall, it was effectively two inline four-cylinders, mounted deck-to-deck like a Commer Knocker. It used two crankshafts (one above the engine and one in the traditional position) and a supercharger. The bottom set of four pistons produced the power, while the top four controlled the inlet and exhaust ports. And I’m sure that description has just over-simplified it to the max.
I saw it run once and it was LOUD!

Now, in the meandering way of such things, the Commer Knocker brought us to Chamberlain tractor air-cleaners, that took us to the Chamberlain race-car, and that now takes us to a bloke named Jim Hawker. Jim was a cousin of the Chamberlain brothers and is really the bloke who got the Chamberlain into race-winning form, mostly by refining the electrical system (he made his own spark-plugs for the Chamberlain for cryin’ out loud).

Chamberlain -8The 'Chamberlain 8' - a wonderful amalgam of supercharged, twin-crank, two-stroke engine with front wheel drive

I met Jim many years ago and in telling me about a car he built as family transport back in the day, he revealed his true genius to me as we sat around on old oil drums in a country workshop, talking cars. Way back when Jim’s kids were still little ‘uns, sunny Queensland (when it was still a collection of fishing villages and beaches) was the annual holiday destination for the Victorian-based Hawker clan. Now, Jim was a big fan of the cars Peugeot was building back in the day; rugged, rear-drive sedans that were properly tough. Only trouble was, the 403 (I think it was a 403) Jim owned at the time wasn’t the fastest thing on earth. In fact, by the time the family arrived in Queensland, it was almost time to turn around and go home.

Jim’s solution was typical of the bloke. He took a pair of Peugeot four-cylinder engines, cast up his own crankcase and modified a crankshaft to take double the number of con-rods. Then, by bolting it all back together, he’d made himself a Peugeot V8. The detail stuff was fascinating too; he worked out that the standard Pug con-rods were way over-engineered and that allowed him to re-thickness the rods and bearings, meaning he could bolt two rods side-by-side on a single big-end journal. That kept it all physically compact, too, and ensured the finished product would still fit in the 403’s engine bay. Apparently, the starter-motor location nearly ended the project but, eventually, he figured out an offset-mounting arrangement that got it all working.

A busy bloke through the day, all this was taking place in Jim’s spare time so, by the time it was ready to rock and roll, the holidays had started. But, having total faith in his own work, Jim fired the V8 for the first time on the Friday arvo, piled the kids into the car and headed directly to Queensland. And it ran like a top all the way. Got them there in record time, too.
It’d be interesting to revisit the Hawker V8. The last time I saw it, it was stored under Jim’s workbench. Anybody know where it is?


And again…

Dinkys -supertoys

Morley, here’s what I recall about Commer Knockers. They were a very popular truck for the following reasons:

They were very light on fuel. Because of the very little movement in the swivel and gudgeon pins, the tolerances could be set at far smaller gaps than conventional engines. They were also cheap to register. This was because, at the time, rego fees were calculated on the swept volume of the engine. This was called the RAC rating. The Commer came in at seven horsepower (or it might have been 13, I can’t remember).

But the engine being so small gave very little engine braking and travelling down Pretty Sally or Toll Bar (Toowoomba) Cunninghams Gap or the long hill into Adelaide had to be approached with extreme caution.

Overall, they were a good, but very, very noisy, little truck. Non-attention to silencers soon attracted the attention of the boys in blue. What finally killed all two-strokes in Australia and elsewhere was their inability to control exhaust emissions.

Now, Detroit diesels: The Jimmy – a godsend to operators who had bought big ex-army trucks with Hercules (big Yankee diesels that were almost antediluvian) or huge V8 petrol engines. The exhaust signature of the Jimmy was unmistakable and every model from the 120-hp six-cylinder units to the 500-hp model used to leak about as much oil as they consumed. A popular truck in the 1960s was a Peterbilt which came with an 8V71 Detroit as standard equipment. Blew everything else off the road.

There was another two-stroke truck engine on the scene in the early 60s and that was a unit made by Foden in England and fitted to its export models. Everybody in the Northern Territory in heavy haulage bought Fodens which were usually equipped with Gardner, Cummins or Rolls Royce diesels. But these new two-stroke engines came on the scene in two forms, one with a conventional supercharger and one with a turbocharger as well. Clearly, Foden was using us as guinea pigs. The rule of thumb was: Two good trips, one bad trip and then a piston-and-liner trip. These engines were so unsuited to tropical heat, they all failed and were replaced by Cummins NH220s. It must have cost Foden a fortune.

Michael Pyper,

Bunbury WA

I’ve heard in the past how the big American diesels landed here in the 60s and proceeded to make pretty much every other heavy-haulage truck look pretty silly. As well as the Detroit Diesels, I’ve heard that the original Mack Thermodyne (albeit a four-stroke diesel) was also instrumental in making American trucks the force they became in this country.

You can see how the formula for a workable British truck might get lost in translation. For instance, a top speed of 40 mile-per-hour might have been fine for a Pommy truckie whose daily run was on narrow lanes to five villages, all within five miles of each other. But bring the same truck out here and ask it to do Melbourne to Sydney overnight, and you had a battle on your hands. But the Yank stuff, built as it was for conditions much closer to ours, simply did a better job.

Can’t say that I’ve had anything to do with Foden two-strokes, but a few blokes I know who are into their old trucks seem to prefer Gardner engines (the five-cylinder, in particular is regarded as a peach). And boaties can’t get enough of Gardner engines to power their projects, so there must be something in it. From what I can gather, the other popular powerplant for a Foden truck was a Thornycroft engine.

And you’re right about the acceptance of the Foden stuff way up north. You still see Fodens grumbling around up in the Territory. The last one I saw was several years ago and had been converted to a crane truck. I spotted it somewhere around Innamincka (I think) but it was still running and seemed to be earning an honest living.


Book full of Commers

Here’s a bit of info on the Commer two-stroke diesel: My wife owned a second-hand book shop for a while 30 years ago and while browsing one day I saw this workshop manual. I can remember as a kid in the 60s seeing Commer trucks around and I liked the unusual exhaust note. It is a very different engine design, so I kept the manual.

Meanwhile, there’s a fella in Yangebup (south-west WA) who has a huge collection of vehicles and I think he has, or at least had, one. Last time I passed through he was working on one of those two-stroke diesels in one of those round-tail 60s tour buses (I forget the make). He willingly started it up just so I could have a listen. About 20 years ago I called in and was admiring his DS23 Citroen and he said jump in and have a drive! He is a very interesting person and seems to love anything mechanical. 

Wayne Morey,


I love second-hand bookshops, Wayne, purely because you never know what treasures you’re going to find. I once found a factory workshop manual for a Kombi I owned at the time. They were changing hands for more than $100 online, but this one was mine for $25. Mind you, I did have to dig through a dozen stacks of old travel guides and dodgy fondue cook-books to find it, but that was half the fun, too.


Dry ice, rattle guns and fast Fords

Ford -turbo -24-valve

Just catching up on some reading. Ice baby was interesting… and pretty cool. Pun intended. Thanks for the tip. You asked about an electronic rattle gun: Mate do yourself a favour and just get one. You’ll never look back. Just so quick. Just be aware that they can strip nuts that aren’t threaded properly on first. You already knew that. I’ve got a Ryobi and it’s great. Bunnings has plenty of them. 

I would love to build a hill climb/competition car like what you’re doing with the Commodore, for fun and games. I may have access to a TE Cortina. I’m thinking Barra I6 and five-speed plus some chassis rails etc etc. Your thoughts would be greatly appreciated.

I’ve also got a 1991 Fox Mustang GT 5.0 convertible that I’m playing with at the moment. It’s still left-hand-drive and can go on club plates now. Well, when it’s finished. There’s a bit to do, but overall it’s pretty good. Just the usual, paint, rubbers, interior etc to go. May do a head, cam and inlet manifold upgrade. Already goes well so that should perk it up.

I have an XY really XW ute that I’ve given the once or thrice over as well; 351 Toploader, nine-inch. It’s fun. It’s not a show car so I don’t panic if I get a stone chip or scratch. Still looks good in Diamond White two-pack though.

Anyway, now I’ve got that off my chest I’ll let you get back to it.

Murray Ashton 

Bentleigh, Vic

Good to hear from you Murray, and I reckon I’ll follow your advice and get myself one of them newfangled electric rattle-guns. Just to be able to rattle on a set of wheels without the damn compressor deafening me would be justification enough, I reckon.

I reckon a TE Cortina would make a darn fine weekend club car and if you can squeeze a Barra six into it, it’ll go like a recently cut cat. That said, it’ll be one hell of a front-heavy mutha. The original lead-tipped arrow, I reckon. Truth be told, you’re probably better off leaving it with whatever engine it currently has (even the Pinto two-litre four-cylinder can be easily and pretty cheaply tuned up) and spending your gold on making the TE stop and go round corners; two things for which it was never known back in the day. I know wrecking yards are chockers with BA and BF Falcons that have been clobbered up the Khyber making them perfect donor cars, but even a free Barra six is going to soak up mucho dollars getting it to fit and then strengthening the rest of the Cortina so that it doesn’t turn itself inside-out the first time you dump the clutch.

My own take on this stuff is that if I’m not prepared to roll it into a ball and walk away from the steaming wreck with no regrets, then I’m not prepared to race it. Which is why I’ll take the cheap, simple option every time and which is why my Bombadore still has a dirty old 202 in it. The other thing I tell anybody who’ll listen is that I want to take my car to a track and race it… not tow it hundreds of kliks to tune it or weld up cracked chassis rails and whatnot.

But let me know which way you go and maybe I’ll see you in the pits at a hillclimb in the not-too-distant.


Twelve down to six

Bmw -8-series

I was interested to see some discussion on the BMW 8-Series recently. I bought a 1992 850i and from the day after I bought it, the EML warning light comes on intermittently and seems to shut down six of the cylinders into a limp-home mode. I replaced all the plugs and leads but it is still there intermittently.

I was thinking of replacing the engine management system with a modern Haltech type setup. Any suggestions? When it runs well, it bloody runs well and sounds great!

Paul Burge,

Tascott, NSW

Okay, Paul, here’s what my BMW specialist has to say: You’re dead right when you say the engine feels like it’s dropping down on to six cylinders from the 12 it was born with. In BMW-speak, EML stands for Engine Management Light and it illuminates because the on-board computer has detected a problem somewhere with something. In the case of your car, the computer’s solution is to shut down six of the engine’s cylinders to try to prevent damage being done.

Changing the plugs and leads is a good old fashioned way of dealing with stuff like this, but according to my source, it’s almost certain NOT to be the problem on an 850i with a lit EML. The only way you can really deal with this is to take the car to a BMW dealership or some other specialist workshop that has the diagnostic equipment to talk to the car. When this conversation between your car and the dealership’s computer takes place, the car should spit out what are called fault codes and the technician will be able to interpret those codes and get a pretty good idea of what’s going on. My man reckons it’s odds-on to be as simple as a sensor somewhere on the car that has failed (or in the process of failing, which is why the fault is intermittent) and is causing the EML to light up.

As for an aftermarket engine management system, you could go down that path but it would probably take plenty of time and money to get it spot on for a complex piece of gear like a BMW 850i. And depending on what system you use, you may lose other functions such as valet modes and even simple stuff like the idle-up function when you turn on the air-con. Many of these aftermarket set-ups are aimed at race-cars which don’t need a whole load of that ancillary stuff, so they’re not always suited to high-tech road cars like yours. And if the problem really is just a dud sensor that’s quick and relatively cheap to replace, you’d want to rule that out first, right? Exactly. Let us know how you get on.



Ein Luftmotor


Did you know that the legendary Porsche flat-six also took to the air? In the 1950-60s, Porsche worked with light-aircraft builders, supplying versions of the four-cylinder engine from its 356 road car. But in the early 1980s, Porsche got back into the air, releasing the PFM3200. Borrowed from the 911 road car, it revved higher than conventional aircraft engines, so a reduction gear slowed the prop to workable speeds. The unit was smoother and made about twice the power of its competitors. There was a turbocharged version, too, but by the time it was on the market, the downturn in light-aviation in the US killed it off after only about 80 units had been sold.

Nader Schmader


You’re doubtless familiar with the `unsafe at any speed’ Chevy Corvair. But did you know that as well as the coupe, sedan, station-wagon and convertible, there was also a commercial range? It’s true. There was a windowless van (dubbed Corvan) and a microbus-style thing called a Greenbrier which could be had with up to eight doors. My fave, however is the ute version which came as either a Loadside (with a conventional tailgate) or a Rampside with a side-loading facility. Why a side-loader option? Because like the VW Kombi ute, the pancake motor under the rear made the load floor a bit higher.


Write to Morley c/o or Unique Cars magazine, Locked Bag 12, Oakleigh, Vic 3166  



Subscribe to Unique Cars Magazine and save up to 39%
Australia’s classic and muscle car bible. With stunning features, advice, market intelligence and hundreds of cars for sale.