The heater is actually nothing more than a small radiator, so by opening flow to it during engine warm-up is counter productive, it's cooling the engine coolant making it take longer to get up to operating temperature.
Your spacer by-pass doesn't close off when the T-stat opens to the radiator...allowing a small amount of coolant to return to the block without being cooled by the radiator.
Mike B
Mike Boteler
1956 Chevy 3100 Resto Rod 1952 Willys M38 Army Jeep 1983 Jeep CJ7 Laredo 1984 Jeep CJ7 +++++ Silver Spring, MD
