Leyland's Australian V6 Experiment

Scanned from the Victorian Club Magazine March 2004



O.K. so we all know about the famous P76 V8 engine .
But did you know in the early stages of development for the six cylinder P76 and Marina's , Leyland experimented with a V6 engine .
Cash strapped by poor sales of the Tasman / Kimberly range and wanting to compete in the 'mid' sized six cylinder class, Leyland examined many ways to reduce costs and supply a suitable six cylinder engine for these cars.
The P76 / Marina six was derived from the Kimberly 2.2 litre six, it self derived from Leyland's then current 4 cyls but before they committed to this engine they had substantial problems to solve for the Marina.
Marina's had a small engine compartment. both short and narrow , due to it being designed only for the 4 cyl and this presented some problems as the Kimberly six was narrow enough but was quite long and heavy in comparison .
The P76 provided no real problems due to its huge engine bay. Before the release of the P76, Leyland were developing an Australian V6 engine. Leyland had decided to 'cut' down' a V8 engine into a V6 for evaluation and testing, prior to committing to enlarging the expensive to manufacture Kimberly six.
Unfortunately the P76 V8 was found to be too wide for the Marina so Leyland used the Rover 3500 V8 as the block is narrower and provided a better fit.
The Leyland engineers literally sliced the Rover block behind the second set of cylinders removing the third set completely and splicing the block back together again. Now although this may sound easy, it was anything but easy.
I believe only two motors were built this way and each motor had to be nearly completely re-engineered after massive welding and machining.
Although most parts were reused some parts had to be completely hand manufactured a namely things like the cam, crank, inlet fanfold and then there was everything else that needed to be shortened, like rocker covers, exhaust manifolds, sumps etc.
In mass profusion, I believe Leyland would have used the components from the P76 V8 instead of the Rover motor. The Rover uses a more sophisticated rocker arrangement in the heads and has other differences and this would have increased costs unnecessarily.
I believe Leyland would have cast a narrow 'Vee' block in the same vain as the Rover motor. These motors would have weighed about the same as the Marina 4cyl, probably shorter and fitted very neatly indeed.
At least one of these motors was fitted to a Marina for road going evaluation trials. Unfortunately it is not known as to what happened to the 'test bed ' Marina , Some of the Australian motoring magazines of the early 70's incorrectly reported this engine as a 'cut down'' Leyland V8 which was incorrect .
Unfortunately British Leyland did not seem to support this engine , preferring to bore out the Kimberly six as they all ready had tooling for the blocks etc , and so the P76 and Marina eventually got the ohc 2.6 litre Kimberly six .
The Marina six has some very creative engineering to fit the 'long six'' .
In actual fact - Buick (the original designers of the Rover engine) actually removed the front cyls in a of block and produced a 'cast iron'' V6 which eventually found its way into our local Commodores in 3.8 litre form.
Unfortunately Buick could not resolve balance issues in these engines and had to resort to a 'balance shaft'' fitted above the cam .
The Buick / Holden V6'' still shares some gaskets with the Rover V8 and the Australian Alloy's version would have been much better .
Another 'cut down'' engine in this country is GMH's attempt at a 'four'' by cutting down a RED motor six and producing the 'Star fire' range of engines used initially in the Torana's , Commodores and some Toyota's .