Was having a spirited debate about using diesel oils in gas engines (racing and marine). One of the well respected members swears everyone off of using diesel oil in gas engines based on his description below. I tend to disagree with this as a possibility. Thoughts?
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His explanation:Merc racing and the NHRA drag race crowd ran into issues with diesel oils some time ago. The Delvac’s, Rotella-T’s, and Dryden offerings all use a heavy metal additive, usually Zinc. Diesels as you know suffer from fuel contamination into the crank case during warm up. The solution is Zinc to provide deposited lubrication upon the lower cylinder walls to prevent piston skirt scuffing as the crank passes through BDC. This finite additive also gets into the combustion chamber and detonates along with the fuel charge. In a lite to moderately loaded gas engine as installed in say a fleet delivery truck, the additive tends to stay in the crankcase.
As the offshore racing crown attempted to use the Shell and Mobil diesel offerings, their knock sensors were mapped showing timing reduction at moderately high to WOT operating conditions. The drag race guys just melted the top rings. The knee jerk reaction was to blame the fuel.
Combustion chamber temperatures in a marine engine operate somewhere in the stratosphere as compared with an automotive application. After altering fuel blends and talking with some of the top researchers in the industry, it was suggested that migration of the Zinc into the combustion chamber was creating a perfect storm of “glowing glitter” which caused pre-ignition and initiated the knock sensors to back out total ignition timing and reduce engine power.
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His explanation:Merc racing and the NHRA drag race crowd ran into issues with diesel oils some time ago. The Delvac’s, Rotella-T’s, and Dryden offerings all use a heavy metal additive, usually Zinc. Diesels as you know suffer from fuel contamination into the crank case during warm up. The solution is Zinc to provide deposited lubrication upon the lower cylinder walls to prevent piston skirt scuffing as the crank passes through BDC. This finite additive also gets into the combustion chamber and detonates along with the fuel charge. In a lite to moderately loaded gas engine as installed in say a fleet delivery truck, the additive tends to stay in the crankcase.
As the offshore racing crown attempted to use the Shell and Mobil diesel offerings, their knock sensors were mapped showing timing reduction at moderately high to WOT operating conditions. The drag race guys just melted the top rings. The knee jerk reaction was to blame the fuel.
Combustion chamber temperatures in a marine engine operate somewhere in the stratosphere as compared with an automotive application. After altering fuel blends and talking with some of the top researchers in the industry, it was suggested that migration of the Zinc into the combustion chamber was creating a perfect storm of “glowing glitter” which caused pre-ignition and initiated the knock sensors to back out total ignition timing and reduce engine power.