In 1951 to 1952 the Trials and Proving Wing at Monegeeta took four vehicles on an extended trial to test the efficiency and reliability of the vehicles in the trial. The documentation that REMLR has in it's archive is Test Instruction 1515 of 8th December 1951. This document relates to the trial of the Holden engine fitted to 1948 Series 1 Land Rover ARN 153952, not to the vehicle or vehicle / engine combination.
Apart from the Land Rover with the Holden engine conversion the other three vehicles taking part in the trials trip were A Rolls Royce B40 engined 81" Land Rover 1951 Series 1 (ARN 107-678) , a Fordson Thames 5T truck with front wheel drive conversion, and a Truck, 3t, 4x4, Chevrolet which was used as a control and load carrier. This Chevrolet is a CMP (Canadian Military Pattern) also commonly known as a Blitz.
The Holden engined Land Rover had completed 53,000 miles of testing before the Holden motor was installed. Before it's installation the motor was run in as per the manufacturers instructions. It used a Holden radiator and cutch, as well as modified engine mounts and a spacer for the bell housing, probably similar to more modern civilian conversions.
The Results
In high temperature and high humidity conditions the vehicle was reliable subject to regular top ups of coolant due to the inefficient radiator. It was also found that the engine retained it's efficiency unless it was being overheated. In high temperature and low humidity conditions the reliability of the engine was the same, and there was no different effect on performance.
On arrival back at Monegeeta on the 30th of April, 1952 the mileage of the vehicles were;
- B40 Land Rover: 18,351 Miles
- GMH Land Rover: 15,597 Miles
- Chevrolet Truck: 6,661 Miles
- Thames Truck: 10,926 miles
The Chevrolet had significantly lower mileage as it did not take part in one section of the trip. The Land Rovers had higher mileages as they were used as scout vehicles for the party as alternative routes had to be taken often due to poor road conditions.
Breakages
A number of minor breakages were recorded in the test result, the only major one being an oil line to the oil filter breaking and the loss of engine oil. One of the more unusual breakages noted is a passenger side windscreen noted as being replaced after being shot! Was it an accidental discharge from a weapon in the back, or an unhappy property owner?
Another peculiar item was a broken gearstick. The breakage report states "lever rethreaded and refitted". This is an interesting fix, most people merely weld broken gear sticks, but these Army engineers seem to have done the repair by drilling the ball and tapped a thread onto the stick.
Performance Testing
Some performance tests were undertaken as part of the trials. These included acceleration and top speed tests.
| Acceleration |
Standard Land Rover |
Holden Powered Land Rover |
B40 Powered Land Rover |
| 0-20 mph |
3.8 seconds |
3.4 seconds |
3.5 seconds |
| 0-30 mph |
8.0 seconds |
7.0 seconds |
7.0 seconds |
| 0-40 mph |
15.2 seconds |
12.3 seconds |
12.2 seconds |
| Max Speed |
55 mph |
54 mph |
over 85 mph |
The higher speed of the B40 Land Rover was because of the top gear ratios. Whereas the normal and holden powered Land Rovers had a ratio of 5.9:1, the B40 powered Land Rover had a ratio in top gear of 3.8:1
Conclusion of Holden Testing
The Army found that the GMH engine needed a larger radiator core to be able to cope with high temperatures. They also found that the sump capacity of 6 pints was considered close to minimum, and it would be an advantage to increase that capacity.
Photographs
As seen below there were a number of images with the trial report. The colour photograph appears to be a video still and is courtesy of Paul Handel. This image was most likely taken while the vehicle was being tested with it's original engine in place.
The copyright of the other photographs is retained by the Army.
A number of photographs are interesting, and the map provides an insight into what kind of distances and terrain was involved in the testing.
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