More Commer Knockers + Cortinas + Mitsubishi Ute - Morley 402

By: David Morley

Presented by

commer commer

Morley reckons paddock bombs teach you plenty about driving and your ability, unravels the mystery behind the dual fuel tanks in GT500 Cortinas and waves the flag again for Commer Knockers


Commer Knockers

The Commer Knocker two-stroke, opposed-piston diesel engine has been keeping the mailbox of this column pretty full lately. It’s a wonderful concept, although it was born to solve a pretty fundamental aspect of truck design back in the 1950s. To keep trucks physically compact, the cab-over-engine design was born as a way of placing the driver on top of the engine, rather than behind it and, therefore, making the overall truck shorter. That made it easier to manoeuvre and, in some cases, cheaper to register in markets where the rego fee was calculated on the vehicle’s length or where there were absolute limits on how long a truck could be.

The brilliance of the Commer Knocker was that it was quite a flat engine, so it would comfortably fit under the floor of the truck’s cabin, making the cab-over thing work beautifully. And while the six-piston, three-cylinder TS3 Knocker gave sterling service across many continents and millions of kilometres, there was better to come. In theory, at least.

See, Commer was well down the path to developing a four-cylinder, eight-piston version of the Knocker, dubbed TS4. It was to retain all the TS3’s virtues of compact shape and good specific output but, with even more capacity, newer metallurgy and improved design elements, it stood to be a real world beater. Of course, by then, Commer was part of the appropriately named Rootes Group, which also owned soon-to-disappear brands like Hillman, Humber and Singer and was itself taken over by Chrysler in the mid-1960s. And being a conservative, US-based company in the business of making money, not unusual engines, Chrysler killed the TS4 dead there and then.

But it makes me wonder what might have been. What could the Commer Knocker have become if it had been developed in line with improving manufacturing practices and technology? Mind you, the Knocker is just one of the victims of mergers, take-overs and globalisation, and that only makes me wonder more about what might have been over the years.

What a world-beating car, for instance, would Peter Brock’s take on the Opel Monza have been had it been green-lighted by General Motors? Here, after all, was a swoopy coupe that shared a lot of its platform with the then-current VB/VC/VH Commodore and could easily have been engineered to accept a five-litre Iron Lion in place of the three-litre six-banger that the Poms considered such a source of pants-wetting excitement. Throw on a set of Group 3 HDT wheelarch flares, a set of those Irmscher rims and those mad HDT stripes. Paint it Tuxedo Black, fit a red Brock interior and stand back. Today, it’d be one of the most collectible Aussie cars ever built and would, I reckon, give an A9X Hatchback a run on the toughness scale. Actually, it’d be a hell of a project car, wouldn’t it? Quick, somebody wake me up before I do something stupid.


Screw Finale

Rubber -bandSaw a neat little trick the other day for removing a Phillips-head screw with a mullered head. You know the sort of thing; a screw with the cross so badly butchered by a previous idiot with the wrong screwdriver that it now can’t be undone. The fix is to find a screwdriver of the most correct possible size and then grab a thick rubber band. You place one layer of the rubber band over the screw head followed by the screwdriver. The rubber can actually improve your purchase to the point where the screw will back out. It won’t work every time, but it sure beats drilling them out.



Harry's Mustang

Ford -mustang

Hey Dave: Got the Mustang going. I had to put in a smart-lock immobilisation-bypass module. They are available online for about $125 and they just hook into the ECU and override the smart-lock function. So all good.

I have the side pipes on the exhaust hooked up and it sounds great. Here’s pic of the five-litre fuel-injected 1992 XR8 engine in the Mustang. I had to customise the export braces as you can see, but with a bit of nouse you can do it. I also fitted a Ford T5 manual box and had to customise the gear box mount as it sits about 50mm back from original.

Harry Ockers
(see Harry's previous letter)


See, THIS is what I love about this industry: You give a bunch of techs a problem and one of them will come up with a solution that is not only simple, but cost-effective. Somebody, Harry, has rubbed up against exactly the same problem as you were having with your ECU, and somehow managed to come up with the fix. In this case, it’s a little box of electronic magic that makes the late-model computer think it’s still living inside a late-model car, but there are plenty of other examples.

I remember back in the 1990s, HSV was trying to figure out how to make the cable-operated clutch in its Commodore-based cars work with cruise-control. It seems crazy now, but right up to and including the VS line-up, the automatic HSVs had cruise, the manuals did not. And it was purely because the cable-clutch and the way it was adjusted couldn’t be made to work with the cruise-control sensors. HSV’s brilliant solution was to adapt the existing pedal set-up to a shorter cable which then operated a small, hydraulic slave unit to actuate the clutch. And bingo: Suddenly your manual HSV could be fitted with cruise-control.

Sometimes the solution isn’t as obvious, but turns out to be simple anyway. A few years back, I saw a split-window Kombi fitted with a late-model VW turbo-diesel engine. Great idea, right? The problem was that the old analogue dashboard had no chance of sending back the correct electronic signals to the computer that drove the fuel-injectors and everything else on the turbo-diesel. As a consequence, the computer, when it couldn’t find the right feedback signal, simply shut her down.

One solution could have been to fit the late-model dashboard, but that would have ruined the look and feel of the car. So the owner took the simple path and left the late-model dashboard hooked up to the computer to send back the right signals. And then simply hid the whole dash assembly under the rear seat. Brilliant.

In fact, we’re all workshop brainiacs when it comes down to it. If you’ve ever flipped a bracket upside-down to make a cable line-up, cut up a Corn Flakes box to make a gasket or put a 34.5-degree bend in a spanner to reach a tricky spot, then you, too, my friend, are a backyard genius. And I salute you.



One for the record

Hey Morley, keep up the good work. Love the workshop, being an ex-mechanic. In response to the dogleg gearsticks in earlier Holdens: In 1973 I bought a HT Kingswood with a 186 and four-speed. It had a layback bench seat (which was called a camping body) with the dogleg stick on an awful Opel four-speed which was factory. About the same time my old man bought a One Tonner with a 202 and four-speed with a bench seat and dogleg shifter. They were quite common back then. 

Meantime, I am moving house so I have nearly 50 years of car magazines of all descriptions that I have to get rid of. So, if anyone is interested in some reading material for their man-cave or shed… In amongst them I found an old pamphlet for Holden One Tonners. The price for a ute with 202, LSD, disc brakes, mud flaps, tonneau-cover and 12 months rego was $2600 plus $625 for the trade-in: Total of $3225.

I also found a Modern Motor from 1971 with the HQ Holden release with the record in it. I actually played the record and it still sounds fine. Keep up the good work.

Phil Douch


Okay Phil, I don’t mind turning this into buy, swap and sell. Not if it’s in the name of sharing the joy of old car mags, anyway. Meantime, I remember that HQ Holden record very well. I used to do a radio show in Melbourne on a community station called Triple R (Many years ago now, does anybody out there remember it?) and we somehow managed to snaffle a copy of the little, floppy, plastic record and then proceeded to play it to death. It was hilarious.

If memory serves, one side had fashion designer and television personality Bobo Faulkner (they don’t make up names like that any more. Bobo, real name; Ann Minchin, left us about three years ago) giving her stylistic opinion of the brand-new HQ. But the biggest thigh-slapper was the road test of the HQ V8 by the then editor of Modern Motor, Rob Luck, who spent the entire test shouting praise over the sound of screaming radials (or they might have been cross-plies; we don’t know). We used to sit in that sound booth and laugh till we cried, knowing that the punters tuned in to Triple R (still the country’s best community station) were doing exactly the same.



Mitsubishi ute

My first ute is a 1984 Mitsubishi L200 2WD that we stripped down for a paddock basher/drift car, so it’s got no doors, no windows, the classic bench seat and some bloody good seatbelts. The motor is an Astron 2000 out of a 1981 Mitsubishi Sigma SE station-wagon and I was just wondering if there were any tips or tricks for getting more punch out of the old girl. Also, what common problems did the 1981-84 Sigmas and L200s have and what motors are interchangeable between the two (Sigma/L200)?

Here’s a quick rundown of what has been done already and what the L200 has got:  Standard five-speed manual; standard drivetrain and diff; 15-inch-wide Toyota LandCruiser rims with Dunlop Le Mans tyres on the back; standard Ford Courier rims with B/F Goodrich A/Ts on the front (for steering); two-and-a-half inch Pacemaker extractors; straight-through exhaust, no mufflers. The rest is standard.

Luke Parker


I spent plenty of time on farms as a kid, Luke, so I’ve got a pretty good mental picture of what sort of mis-treatment your old Mitsi gets on a pretty much daily basis. Paddock-bashers are about the most fun you can have with a couple of mates, a wet paddock and any old sort of shitheap you’ve managed to save from the scrappy. By an odd coincidence, my first dedicated paddock bomb was also a Mitsubishi; a 1968 Colt 1000, to be exact.

The great thing about paddock bashers is that they don’t need a lot of power (thankfully in the case of my little Colt) so I wouldn’t bother going for anything expensive like a turbocharger or even a bigger engine. If the two-litre is still bagging them up, stick with it. That said, I believe the 2.6-litre Astron is a pretty simple swap in to the L200. So if one of those big-block four-bangers happened to fall into your lap, well… Mainly, though, the trick is to make sure you absolutely optimise what you’ve already got. Plugs, points, leads and make sure the timing is spot on. This stuff doesn’t cost much at all, but can really make a difference to how a car drives.

The one thing I would do is bolt the doors back on. Even with good seat belts, you wouldn’t want an arm or leg flying out as she rolls, would you? And mum will be happier, `cos the doors will keep SOME of the mud out of the cabin, meaning less frequent clothes washing. Then, I’d grab Dad’s stick-welder and find some old water pipe and weld me up a roll-bar of some kind. A hoop just behind the cabin’s rear window with some diagonal stays down into the tray should do the trick. Safety is my middle name, after all. While the welder is out, yank the diff centre and weld that up; world’s cheapest spool diff.

Meantime, the best way to improve your car’s power to weight ratio is not to add more power, but to subtract more weight. So fling the bonnet and the tailgate, but make sure you run an air-cleaner to keep the bigger clods of dirt out of the carby. Remove the headlights and tail-lights, too, as well as the grille. Straight on to eBay with those and that should buy a tankful of juice or two. Those LandCruiser rims on the back must have messed up your gearing something awful, but hey, that’s what a gearbox is for, right?

From what I can remember, the Astron was a better mousetrap than a lot of what the competition were doing back in the day. When Datsuns were deafening their drivers, Toyota owners were dying of boredom and Mazda four-cylinder owners were pouring Ajax down the carby to try to stop the engine burning oil, those Astron-powered Sigmas seemed to be a cut above. The biggest recurring mechanical problem was a stretched timing chain, although I recall the 2.6 was worse than the two-litre for this. Make sure you don’t overheat it, though (cracked cylinder heads, blown head gaskets) and it’d be worth running coolant in it rather than tap-water to keep corrosion at bay. If you want to get really creative, why not embark on a program of mass centralisation. The radiator and battery could both be moved into the tray, just behind the cabin, taking weight off the front end and making her turn better. The longer radiator hoses will also increase the capacity of your cooling system. Along the way you’ll also learn about making brackets and mounting points and even a bit of electrical wiring.

Beyond that, keep giving it the berries. And to all those who reckon I’m doing the wrong thing encouraging a young fella to go out and play in the mud, put this magazine down and choose something else from the pile of books in the doctor’s waiting room. Every young driver will experience oversteer, understeer and what happens when they overstep the mark at some point in their driving career. If they can first learn about it at relatively low speed in a nice safe paddock, then they might just survive to be able to put that knowledge to use on the road when it happens unexpectedly. And if you can’t see how sliding around some farm tracks in an old car is incredibly good fun, then I believe the doctor will see you now.


Cortina -500

Cortina GT 500

Forgive me for the following: I’m trying to avoid becoming a grumpy retired engineer. Your column on the Cortina GT 500 kinda missed one important factor. The additional long range fuel tank was one large tank fitted across the rear of the boot and above the standard tank. While this allowed the GT 500 to do 500 miles at Bathurst with just one refill, the second filler neck allowed the same volume of air to escape as the regulated single fuel churn was up-ended on the other filler. It cut refuelling time in half. This was Harry Firth after all and his book, Ford and I, has many photos and detailed descriptions of the GT 500 modifications.

On another matter, Glen Torrens column on Aussie verses Yank car language committed the usual crime of saying you can interchange `engines’ and `motors’. In engineering terms, an engine is fuel powered, such as petrol, diesel, LPG etc. A motor is electric only. So there is no such thing as a petrol motor or a power window engine.

Ernest Litera

Avonsleigh, Vic

You know what Ernest, this GT500 fuel-tank thing has been bugging me, too. At first (and it’s the accepted wisdom) I thought each filler fed one tank (the original under the floor and the GT500-specific auxiliary tank between the rear shock towers). But then I started getting letters, like yours, telling me that one of the filler necks was to allow air out during the refuelling procedure. But that raised more questions than it answered: Were there two separate tanks, or just one big one; did the racing rules of the day allow for refilling from two fuel churns at once?

And because there were only (about?) 100 GT500s made to homologate them for racing and a high percentage of those would have gone to the big parc ferme in the sky by now, I don’t know of one I can visit for a look-see. But finally I found a picture of the layout in the boot and it seems that the twin filler necks both feed into the auxiliary tank. From there, the auxiliary is linked to the (standard) main tank with the latter’s filler neck, in the usual position next to the rear number-plate, blocked off. It looks as though either filler would act as a fuel-in or air-out deal, which would make sense, because the safe filling side would be different on clockwise and anti-clockwise circuits and depending on whether the pits were on the infield or outfield. As in, you wouldn’t want to be standing on the transit-lane side of a race-car, juggling 50 litres of explosive fuel over your left shoulder while other race cars bomb past trying to make up milli-seconds (no pit-lane speed limit in them days). Can anybody out there add to this, or does somebody have a GT500 we could examine? Purely in the interests of accuracy, you understand.

As for Torrens; well, I reckon we’re all guilty of mixing up our terminology now and then, aren’t we? I mean, you’re right about a motor being electric and a fuel-burner being an engine, but I can see Torrens’ point. And while I’ve never seen an automotive powerplant that can grind flour, I’m happy to refer to it as a `mill’. Let’s be honest, if we all wrote to exacting, engineer-approved standards, this’d be a pretty dry old magazine to read, no? But point taken.



Commer at work

I recently stumbled upon something about Commer Knockers. Although I sense, Dave, that you’re not a truck ‘tragic’, you may like the attached pic. This semi is about half loaded for what was a regular haul to the Sydney CBD, from the sawmill that my late dad managed at Wallerawang NSW. Can you imagine the sound of this machine crawling up Mt Victoria Pass?

Eric Waples

Albion Park, NSW

What a great photo. I love this sort of thing…not a happy snap of the day dad bought it home from the dealership, but a proper record of a vehicle’s working life. And yes, Eric, I can well imagine the racket it must have made hauling tons and tons (and it was tons back then, not tonnes) of timber up a steep hill in low-range with that two-stroke diesel hammering away at full chat.

What continues to amaze me is just what hard yakka it must have been driving a fully loaded truck back then on the goat tracks that passed for Australian highways. And freeways? Forget it!  And although the Commer Knocker was known for being a pretty powerful unit in its day, hauling all those tons with just 105 horsepower under your right boot must have involved plenty of gear changes. I guess the engine’s real strength was its torque (which is what counts anyway, right?) and with 366Nm available from just 1200rpm, the Knocker was a proper slugger. Still, with no air-con, no synchromesh and pretty much zero in the way of creature comforts, the job of being a truckie must have called for plenty of grit.



Running afoul of the law

For a long time (ever since I was a kid) I’ve been into cars. While I was a struggling student at university, I reckon I spent every break flicking through magazines, dreaming about what I might be able to get one day (although that Mclaren F1 continues to evade me).

As time went on, though, I was fortunate enough to be able to buy one or two of the ‘dream cars’ from my youth. I picked up a tough looking Falcon ute and a custom trimmed, 202-engined HT Kingswood station wagon.  Being blessed with some big sheds at my house I always took the point of view that one more  wouldn’t hurt. And it’s fair to say I got addicted to the thrill of finding hidden gems. There were occasions where I would simply dial the number in the ad, offer cash and nail down a deal before anyone else had the chance to have a look.

Soon I had more than 10  cars in the shed. Then I started listing them online and before you knew it I had made both a bit of shed space and a tidy profit. I was having a great time.

Then, out of the blue, I got a letter from Consumer and Business Services, saying having bought and sold in excess of four cars within a 12-month period, I had `breached s7(1) of the Second-hand Vehicle Dealers Act’. I was shocked – I could be hit up with a significant fine. I never thought of myself as a gun wheeler dealer and always felt like I had simply got lucky if I made money on a sale.

Turns out, IT DOESN’T MATTER. I could have lost money on every car I sold and the very specific regulations prohibiting individuals from buying/selling more than four cars in a 12 month period without holding a Second-Hand Dealers Licence still would have applied. As I found out, it doesn’t matter if you paid cash, swapped or did any other sorts of deals either.

There’s nothing wrong with ‘collecting’ and then lightening the load if it’s getting too unwieldy. But, as I found out, the laws that govern this are very specific. I found Consumer and Business Services to be understanding (I think there’s a few classic car nuts in there too) and was fortunate enough that I was able to resolve my breach of s7(1) via an ‘Enforceable Undertaking’ as opposed to a big fine. Either way though, it wasn’t worth the sleepless nights for something that I should have been aware of in the first place.

Duncan Gordon


You raise a very interesting point, Duncan. Regardless of what you think about the law as it stands and whether four cars should make you a car-dealer or not, it remains that the law is the law (and I’ll assume it varies from State to State). And in this electronic age where the trail can be followed back to whoever, whenever, there’s no ducking and dodging it.

While it might seem a bit unfair to those of us who like to flip cars for a bit of fun and relaxation, I can see why such a law would exist. It’s basically there to stop backyarders flogging dodgy pieces of crap to unsuspecting punters and using their civilian status to dodge warranty claims and having to guarantee clear title. You know, all the stuff that used-car dealers have to deal with. So you can thank the Arthur Dalys of this world for the fact that such legislation exists at all.

Meantime, I’m pleased to hear you got a sympathetic hearing from the gummint department. And I’ll bet being let off with a warning was a huge relief. And thanks for sharing your experience, because it’s a fair bet that there are other readers of this magazine who might be about to flip their fifth car for the year, who need to check the law in their home State or Territory first. And I wouldn’t be thinking that they’ll never catch up with me. Government departments like this one have incredible powers. They’re a bit like the Tax Office; nobody – not even the police – has the same powers as the ATO in some areas. And they’re certainly not afraid to use them. Which is why, even though many of us disagree with how our taxes are spent in some areas, the smart ones make damn sure they pay their tax every year and don’t try hiding income or making false claims. And as you found out (almost) the hard way, Duncan, ignorance of the law is absolutely no excuse.



Screwed up? Moi?


I’m on a roll here, so I’m sticking with the Phillips head screw. It is, of course, named after an Oregon businessman name of Henry F Phillips. But Phillips didn’t invent the thing, that was down to a bloke called John Thompson. But as a marketer, Thompson made a great inventor, and he couldn’t interest industry in his new screw. That’s where Phillips stepped in in 1935, buying the design from Thompson. Phillips’ genius was that he could see the possibilities in the thing, and he was a pretty sharp salesman, too. In fact, by 1940, 85 per cent of all screw-makers in the USA had licensed the design.

Prince of Screws

CadillacSpeaking of Phillips head screws, have you any idea why they were invented in the first place? The Phillips head screw came about in the 1930s as global industry was moving towards the production-line concept and automated assembly in a big way. The self-centring nature of the Phillips head design meant it was perfect for production lines where powered, automated screwdrivers were used. One of the first adopters was GM which used Phillips head screws on the production line of its 1936 Cadillac.


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



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