Development of an Ultra-Low Silicate, Phosphate-Free, Extended-Service Interval Coolant, Supplemental Coolant Additive and Maintenance Practice for Use in High Output Off-Highway and Powerplant Internal Combustion Iron Block Engines. 961819

This paper reports how, as part of a continuous quality improvement program, a major high output (over 1000 KW) engine OEM and its coolant technology supplier identified specific opportunities for improving the coolant chemistry used in the subject engines. Specific objectives included:

• optimize the stability of the coolant chemistry as evidenced by the reduction or elimination of radiator tube plugging;
• reduce the need for cooling system cleaning and maintenance;
• extend the life of the coolant to coincide with the time period between engine overhauls;
• Improve maintenance simplicity and tolerance for errant maintenance practices.

The existing coolant program, derived from successful highway engine service practices, was reviewed and the chemistry of the supplemental coolant additive (SCA) was modified to more precisely address the characteristics of the subject engines. In particular, the SCA was reformulated without silicate, since the subject engines contained no aluminum. The data contained in this paper report the performance and reliability of the engines and cooling systems in particular, when operated with low-silicate, phosphate-free, low-dissolved-solids engine coolant maintained with an SCA containing neither phosphate nor silicate Aqueous ethylene glycol and water-based coolants were evaluated. The existing recommended coolant change interval was ignored and the reliability of the engines and components recorded. The data support conclusions that this chemistry and maintenance practice, together, provide improved cooling system reliability and service readiness, while lessening the environmental impact of frequent coolant disposal.