View single post by Ron Earp
 Posted: 04-02-2005 08:15 pm
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Ron Earp

Joined: 03-12-2005
Location: Cary, North Carolina USA
Posts: 339
Mark Rosenbaum wrote:
Originally posted August 2004.

and a horsepower's worth of heat out the exhaust. This being so, a JH engine at full throttle makes enough waste heat to warm its entire coolant supply by 7^F a second. If this engine normally runs at 180^F and the coolant boils at 230^F when pressurized, then it could run at full throttle for no more than (50^F)/(7^F/sec) or a mere 7 seconds before its coolant turned to steam. In practice, of course, the waste heat warms more than just the coolant, and the cooling system transfers much of the heat to the environment, so the time to boilover would be considerably greater. 


Let's hope it is considerably greater! We'll be racing the JH in May and if all goes well it'll do the 30 minute sprint races and the 1.5 hour mini-Enduro.  For both of these races it'll be full throttle between 6k-8k only letting off for four braking zones. 

The only changes I've done to the JH motor for cooling is a four core radiator, and probably more importantly, a larger oil cooler, an Accusump oil pressure system, and a two filter remote mounting oil filtration system.  Many times people overlook what oil does in a motor, sure it lubricates, but it takes a lot of heat out an an engine as well.  This system will give me me about five additional quarts of oil in the system and greatly increasing the cooling capacity of the entire system.