As you may already know, the original design of the 6-71, two-stroke diesel engine turned 50 this year.

There has been a great deal regarding the DDA family of engines and the engines built up by other manufacturers from DDA blocks.

One of the brightest stars in the constellation of "other" DDA-based engines is Johnson & Towers, the builders of the  8V-92TIBs.

"Normal"  8V-92TIs crank out 735 hp or so. These J&Ts yield 750. However, just as importantly, these engines weigh in around 450 pounds less than the competition. 

This is the result of making such components as exhaust manifolds, engine mounts, oil pan, and the flywheel housing from a special aluminum alloy. Also rather remarkable is the fact that this engine is 8 inches narrower that the configuration sold by others; a result of J&T's use of a single water-cooled turbo (a sharp contrast to DDA's own twin-turbo configuration).

To help the engine deal with the thermal stresses that are developed when power is crancked out on this scale, the 8V-92TIB has a high-heat-resistant ceramic coating inside the exhaust manifolds.

The "B" in 8V-92TIB stands for bypass blower. The objective here was to provide plenty of moxie for lifting big sportfish and the like on plane, without the smoke which often accompanies such duties. They've succeeded. 

This review/article originally appeared in Boating Magazine, March 1988 and is written by Allen D. Berrien. For more great powerboat reviews, visit their website and subscribe at: http://subscriptions.boatingmag.com/