New smoke test delayed
Page 77
If you've noticed an error in this article please click here to report it so we can fix it.
• -It is out of the question that the smoke test for diesel vehicles will be reintroduced into the MoT on 1 September," says the VI's Kevin Rooney. But during the Federation of Engine Remanufacturers' show he predicted that the test will be recon. stituted and reintroduced by the end of the year.
Research has shown that toothed cam belts drive mainly by friction. When holding the engine at the governed speed it tightens and slackens, causing slippage or a break. To avoid this the new test will not hold the engine on the governor and will ensure the belt is warm before starting.
The number of engine runs is likely to be reduced from 10 to six with only three clear runs being needed for a pass. The Department of Transport is expected to provide insurance cover against claims for engine damage.
A total of 52 claims were lodged for engine damage caused by the test before it was with drawn. They have all been been investigated by the DOT. Four engines failed in the test station: the rest failed afterwards.
Rooney said that it was impossible to consistently stop the acceleration at a pre-set limit so the new test must take the engine up to governed speed. Some engines smoke at the bottom end and some at the top, he added.
While the test is suspended the VI is looking at variations in the smoke meter readings and is retesting each manufacturer's meter.
The logarithmic K scale may be replaced by a linear one to gain public acceptability.
New MOT procedures will come into force in 1996 when an EC roadworthiness directive comes into force and catlyst equiped cars require testing.