July 16, 1985 - Maritime Reporter and Engineering News

Wichmann Reports On First Year Of WX28 Engine Operation

A/S Wichmann of Norway reported the first WX28, a V-8 heavy-fuel engine, passed its first 12 months of operation earlier this year. The engine, which has a maximum continuous rating of 3,000 hp at 600 rpm, has now logged a total of 7,000 operating hours on board the M/V Bommeloy.

In addition to the operation of the WX28 on board the Bommeloy, extensive heavy fuel tests have been carried out on a 4-cylinder WX28 engine on a testbed.

The operation of these two engines has demonstrated that the WX28 satisfies the heavy demands and stresses placed on the engine. The prototype V-8 on board the Bommeloy has not had any unanticipated breakdowns during its first year of operation.

An inspection performed on the valveless-turbocharged- medium-speed engine revealed practically no cylinder wear. Clean ports and a clean combustion chamber indicated effective scavenging and combustion. The heavy fuel tests on the 4-cylinder WX28L4 show cylinder wear well below 0.02 mm per 1,000 operating hours, a wear giving a liner lifetime of a minimum of 40,000 hours.

The WX28 has a cast iron piston skirt with a steel piston crown. The skirt is equipped with a shrunk-on bronze sleeve. Bronze is an excellent bearing material, and the piston skirts look new after one year of operation. The piston crowns have hardened ring grooves, and the groove height was well within the tolerances for a new crown.

The piston is equipped with three compression rings at the upper end of the piston. Ring No. 1 is a plasma-free-rotating ring, No. 2, a chrome-plated-free-rotating ring, and No. 3, a fixed-cast iron ring with a special gas-tight joint.

The ring grooves were clean upon inspection, and there was no fouling. The ring wear on the V-8 on board the Bommeloy was so minor accurate estimates on ring lifetime are not possible.

Heavy fuel tests on the L4 indicate, however, an interval of 8,000 operating hours between ring renewals.

The oil scraper ring is located at the bottom end of the piston and is working below the ports in the cylinder liner, where the liner has no wear.

No wear was observed on these rings.

The engine has separate cylinder lubrication from a hydraulically operated cylinder lubricator.

The lubricator is essential in reducing cylinder and ring wear, as well as keeping them in excellent condition.

The WX28 differs from earlier Wichmann engines with regard to the auxiliary blower. The engine has a fan (radial compressor) operated hydraulically with oil from the engine's lubricating oil system. Hydraulic operation allows the blower speed independence of engine speed, which gives greater flexibility for adjustments.

The system has worked well and has proved reliable and simple.

The turbo charger, main bearings, cylinder cover and fuel injection systems have all been functioning excellently, both on the V-8 aboard the Bommeloy and on the L4 on the test stand.

According to Wichmann, the first year of operation of the WX28 has been a success. The V-engine has had several operating profiles conducted, with periods of full power, part load and frequent maneuvering. No problems have been reported of any kind, and inspection of the cylinders and the pistons show a clean engine with optimal conditions in both the cylinder and the combustion chamber.

For further information, including a complete detail-filled brochure, Circle 51 on Reader Service Card

Other stories from July 16, 1985 issue


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