Poor Reconditioning a Smoke Cause

21st September 1962, Page 89

21st September 1962

Page 89

Page 89, 21st September 1962 — Poor Reconditioning a Smoke Cause

Noticed an error?
If you've noticed an error in this article please click here to report it so we can fix it.

NIONG criticisms made by the k Institute of Road Transport Engiers Vehicle Exhaust Study Group in eir second interim report released today e some on the quality of reconditioning el injection equipment available to

erators of diesel vehicles.

'The report Set out to examine the luence of fuel injection equipment and el on exhaust smoke. The painstaking cautions successfully taken by fuel ection equipment manufacturers, to &ICC to the standards demanded by tat are described as modern " near-the ceptable-smoke-limit " engines • are knowledgecl. The service exchange lemes that purport to offer replacement its to factory standards are criticized; .wever. Although manufacturers' pots were said to recondition to factory nits, the proportion of companycrated depots is stated to be small it-mitred with the number of appointed ents and " free-lance" repairers..

The members of the Group and other embers of the I.R.T.E. have provided any examples of the inadequacies of the its reconditioned by such concerns, ken as a grout). Large fleet owners had und it necessary to install special testing uipment and employ skilled staff to .eek service exchange units. Operators small or widely dispersed. fleets. unable do so. arc obliged to rely on the stanirds set by the repairer. Economic essure to produce service exchange tits at relatively low fixed prices is ought to he among the causes.

Another factor which is considered to of influence is the absence of a stantrd specification for testing recondi3neci units. An injection pump set to c nominally correct figure on one sting machine can be found to give a gnificantly different result on another achine. A variety of different machines Id techniques are used for testing jectors.

On fuel, the report states that vehicle ?erators, especially on the p.s.v. side, we in the past preferred to buy fuel of igh specific gravity to obtain the maximal power and mileage from each illon. It is considered that specific 4avity is the fuel factor that influences ic emission of exhaust smoke most of .1. "Ibis is partly because it gives a rough idication of the distillation range—a igh gravity corresponding to a high roportion of the less volatile products .hich tend to produce marginally more rioke.

1-loWever. the variations due to this ause are considered small. A figure of 2-1 to 3 per cent, has 'been suggested as the maximum extent to which the smokelimited power curve could be raised by a change in fuel quality, whereas incorrectly serviced injection equipment—even one malfunctioning injector—can lower the same curve by 30 to 50 percent. The group accept the evidence that fuel additives have been found tei he ineffective in reducing smoke emission.

• The group's recommendations; in addition to the call for a national body to consider exhaust smoke emission made in its first interim report, are as follows: Standard specifications for testing reconditioned fuel injection equipment should be established; standards of workmanship and a code of practice for fuel injection equipment repairers should be set up by a suitable organization; and operators should be advised against the use of high specific gravity fuels, consideration being given to the inclusion of a specific gravity clause in a dery fuel specification.

Renault Price Cuts I T was announced On Wednesday by Renault, lid., London, W.3, that prices of the Estafette standard 15-cwt. van and the pick-up version had been reduced by £10. The price of the van thus becomes .E639 and the pick-up £619, phis L20-if a Jilt is fitted. The Estafettc high-roof van is unchanged at £690, whilst the figure of £425 for the Fourgon 6-cwt. van is unaltered also. The new 12-seat bus, an example of which can be seen in the Demonstration Park at Earls Court, has been fixed in price at £759.

B.M.C. Improvements LATE items of news from B.M regarding modifications to vehic in the Austin and Morris ranges rev that all the trucks will be equipped w larger. rear-view mirrors and that, wh applicable, an improved type of cen propeller shaft journal is being fitt On the J4 van, a loading door is n fitted on both sides of the body, and the case of the J2 van. the side load door has been improved to all opening against the panel.

An introduction at the Show by Girling,L d., is the latest venion of the FCSS cam brake, which is now available with 0.5-in. or 0.75-hr.thick linings. A 0.75-in, adjuster is incorporated to cater for brake-drum A/dunning of up to 0.25-in., and a de-tensioner device is fitted to facilitate .shoe changing by removing tlw load from the shoe-return springs.