Rebuild Diesel ... Is it worth it?

[RDKinard]

I remember the '56 chevy that we rebuilt with a 4-barrel Holley carburetor, high compression head and racing cams. She went from 200+ to 350+ hp!!

Is there any chance to rebuild my Universal Diesel Model 5432 (now M-40) to achieve any similar performance improvements? Hey, I'ld settle for a 20% improvement if it cost me a fraction of the $10,000 the marina is asking for a new diesel.

Any experiences rebuilding diesels?

Captain Rich

[mattotoole]

I assume this is a sailboat, as you're asking in the sailboat forum. If your engine will drive your boat at hull speed already, a more powerful engine won't do anything for you anyway. You'd need *a lot* more power to go any faster, and that's expensive, whether you're modifying or repowering. Chances are, you'd be better off selling your boat and buying a bigger one, if speed is a concern. With muscle cars they say there's no substitute for cubic inches. With sailboats there's no substitute for waterline length.

To answer your question more directly, "tuner" parts are generally not available for marine diesels in the same way they are for automobiles. Sometimes there are higher powered (turbocharged) versions of the same engine, but I doubt you could duplicate them economically by rebuilding with new parts.

FWIW, those Chevy 350s you mention have been used in many boats, yielding great power for the purchase price. However, any "savings" is quickly eaten up by poor fuel economy, these engines not having been engineered for marine use from the outset.

[FAST FRED]

Depending on the experience level of the rebuilder , a rebuild is great.

But there as many "rebuilds" as rebuilders.

First find out what is WRONG with your engine , and post the performance specs and assorted parts . Engine hp/rpm and speed , tranny ration, prop size etc.

Most likely you will only need a better match of the engine to the boat to get 20% better economy .
Unless your speed is very sub normal , you may NOT see a 20% speed increase with out doubbling the engine size.

FAST FRED

[gonzo]

I rebuild engines routinely. If you find a reputable mechanic, it should run as a new one. Do you think your boat is uknderpowered? What size/displacement is the boat and what speed do you get?