Polaris was unique in that they mounted the heat exchangers beneath the running boards. The water pump was belt driven from the crank on the recoil side, as was common on these early liquid cooled engines. The 500 triple used a thermostat located on the coolant outlet with the coolant entering through a water manifold above the exhaust ports flowing up through the head and exiting out the rear of each cylinder head into a common header. Plug fouling was always an issue with the triples if the carbs were not set up just right, also due in part to the much weaker spark ignition systems.
Polaris indy 440 liquid cooled how to#
Fine-tuning the motor was a matter of knowing how to jet your carbs for air temperature and barometric pressure. There were no fuel mapping and temperature sensors monitoring air temp, engine temp, and throttle position. Polaris tuned the motor to run between 7800-8000 rpm’s claiming the power was close to 100 hp which, back in the late 70’s, was equivalent to owning an 800 cc sled of today. The result was the best sounding sled to hit the snow, and even today the sound of a triple two stroke is music to any motorhead’s ears.
Polaris indy 440 liquid cooled free#
Typical of all early Polaris motors was the piston port induction (intake) with the exhaust ports connected to a three into one manifold that had been used on early Polaris Free Air triples dumping into a tuned pipe and silencer. The mono block triples would not appear until 1993 with the 580 cc XLT.įuel delivery into the intake ports was with Mikuni VM34 round slide carbs sucking air through an intake box, which drew air from behind the windshield. The triple used 6 port individual cylinders and heads on this first version of the famous Polaris triple.
The 500 was essentially a 2+1 version of the 333 cc TX-L engine. They built the new engine using the short (55.6mm) stroke that Polaris had been using since ‘76 on the 250 cc and 340 cc engines. Polaris labeled their motors “Superstar” and for good reason. Everyone wanted a production version of the 440 triple and Polaris finally offered it – bumped up to 500 cc. They were running two different versions of the 440: one had 6 ports, the other had 8.
Polaris had been cleaning house on the oval tracks in 19 with an all-new 440 cc triple liquid-cooled Fuji motor housed in the all-new RX-L chassis. The First Production Liquid Cooled Triple With the company’s 25th anniversary on the horizon the engine department (led by Jerry Schenk) began work on the 500 triple liquid. While Polaris had released the highly successful TX-L in 1977 to compete in the cross-country wars, and it was wicked-fast for a 340 cc production sled, the new 440 cc LQ sleds, however, were selling like hot cakes and Polaris knew they had to up the ante.
Polaris marketing recognized the void in their lineup when Arctic Cat, Yamaha, John Deere and Kawasaki had 440 cc liquid cooled performance sleds in their lineup. The new 500 Fuji (Superstar) motor was the forerunner of the 600 and 650 Indy triples that propelled Polaris to become the market leader during the late 80’s and 90’s. It would be three years (1979) before the first triple liquid appeared. The TX 500 was in production until 1975 when Polaris introduced the redesigned 1976 TX free-air models (250, 340, 440) based on the successful Starfire race sled chassis. I remember when these came out and it was an over the top production sled featuring a 500 cc three cylinder free-air engine with three Mikuni carbs and a three into one exhaust. The first production triple was introduced in 1972 as the TX 500 Limited. Polaris had worked with Fuji to build a number of three cylinder engines since 1970 for their race sleds. Subaru) who had been working with them since the late 60’s. That wasn’t the only difference: their engine supplier was Fuji Heavy Industries (a.k.a. Back in 1979 when Polaris Industries was celebrating 25 years in business they were a much different company, producing only snowmobiles.