gingerfold:
The Enigma of The AEC V8 Engine: Why Was It Ever Produced
Extracts from an article by Robert Fryars, former AEC Director of Engineering and Leyland Group Chief Engineer.
This will answer some questions, and no doubt raise others, but it does explain plenty. We need to start in 1961.
At that date AEC (or ACV group) was an independent company but it was seeking a partner. The Board of Directors believed it needed to be part of a larger grouping to gain benefits from economies of scale that would allow them to compete in Europe and to counter the threat of continental manufacturers. In mid-1961 ACV was in quite advanced talks with BMC about a merger.
In the midst of these discussions Guy Motors went into receivership and it was acquired by Jaguar Daimler. Jaguar then entered discussions with ■■■■■■■ for them to manufacture ■■■■■■■ V6 and V8 engines for Guy. These engines were to be produced in the old Henry Meadows factory next door to Guy.
AEC was an important supplier to the “loose engine” market, and Guy was a large customer for AEC engines. John Bowley, AEC General Manager, met with Lofty England of Jaguar and told him that AEC could match whatever ■■■■■■■ was offering.
John Bowley requested a V engine study from his engineering team. Bob Fryars and Keith Roberts obtained copies of the ■■■■■■■ V engine patents and they discovered that ■■■■■■■■ cleverly, had patented the best stroke and bore ratios. To avoid infringing the ■■■■■■■ patents the options were either a long stroke tall V engine, or a squat over-square V engine.
It was decided that an over-square V6 at 90 degrees, an angle essential to fit in a chassis, would be very rough running, so a V6 option was discounted.
So, AEC was looking at a very over-square V8, a design which was unprecedented and one that was well outside of any direct injection combustion chamber relationship.
Engine noise. Theo Priede, then of CAV, had devised a formula linking Diesel engine noise emissions to the square of cylinder bore diameter and to rotational speed. An over-square Diesel would be very noisy, adding to the difficulties.
A short stroke in-line research engine was made by AEC. A decision was taken that a V8 scheme would only go ahead if it could be fitted under BMC’s new FJ cab.
1961 turned out to be a bad year for the motor industry and the UK economy in general.
John Bowley at AEC had his V8 engine brochure by late Spring 1962. (But no engine)
In late 1961 Rolls Royce complicated matters by suggesting a tripartite arrangement with themselves, ACV, and BMC. This was soon discounted and merger talks between ACV and BMC resumed. ACV believed that the lighter, mass produced BMC commercials would complement the AEC premium range.
1962 the ACV / BMC merger talks were well advanced, there was a good chance of an agreement, and outline terms were drawn up. Then BMC’s financial forecast for the year looked grim and ACV suspended talks, ultimately to walk away.
ACV was high and dry, still needing a partner, but no suitor in prospect. ACV previously had considered Scania Vabis, but had not thought it to be practical. There was only one viable course for ACV, and that was Leyland Motors.
But Leyland itself wasn’t in a good position and it was in dire straits financially. It’s heavy vehicles were overweight and expensive. Leyland’s propitious purchase of Standard Triumph was threatening to bankrupt Leyland itself. In the background Chrysler Motors was watching with events with interest, waiting to pounce and buy a controlling stake in Leyland.
Enter the saviour in the shape of Stanley Markland, who had turned Albion Motors into a profitable and efficient operation. Markland was parachuted into Standard Triumph and by heavy trade discounting he started to quickly reduce a huge stockpile of cars. His was a very risky strategy, but by generating badly needed cash flow it enabled him to keep the business afloat and make economies in manufacturing.
With matters improving Leyland saw off the Chrysler threat and opened talks with ACV. Within three months of negotiations starting a deal between ACV and Leyland was agreed in August 1962. Donald Stokes was heard to comment “buying AEC will solve all our problems”.
All AEC projects were discussed with Leyland and nothing more was heard about the AEC V8 engine project for two years.
In that intervening two years, in secrecy at Leyland, development and investment of the Tattersall 700 engine had begun. This would eventually be downsized to the fixed head 500 engine. The first prototype 700 engines disintegrated within minutes of going on test, irrespective of the fact that they were too big and heavy to fit into any road going vehicle. (The Tattersall 700 engine was loosely based on the Leyland battle tank engine).
When the results of the 700 engine tests were presented to the board panic set in because Leyland was now devoid of a higher power engine. So in late 1964 AEC was urgently requested to prepare an updated concept paper for its V8 engine, with the proviso that it had to fit under the Ergomatic cab, introduced at the 1964 Commercial Motor Show.
It seems clear that Scania had already won this race by 1964 based on nothing more than realising that a 127 x 145 V8,that’s only 7 inches longer,2 inches wider and 7 inches lower than a Detroit 8 v 71 can be made to fit in a truck that will meet all Euro regs including UK. 
So the 700 was a grenade great let’s reduce the capacity to 500 that’ll fix it.While we also get on with making a V8 that will fit in the Ergo rather than make a truck which will fit around a decent V8.Then we threw loads of the public’s money at these muppets to pay for their mistakes.
