The point that is missed here is the need for a pressure system and the
more pressure the better. 22 lbs is pretty common. It is not so much to
raise the boiling point which it does help but to eliminate small air
pockets that cause localized steam and high temp areas.. I have worked
on some engines that raised the pressure to 30 psi before even starting
the engine..some of these ran at 50 psi under a load.
Dave Dahlgren
ardunbill@webtv.net wrote:
>
> Hi Folks. Read the items about cooling with interest. I have a 15 gpm
> Jabsco 12V marine coolant circulating pump which they tell me is
> in widespread use for cooling converted auto engines in marine use where
> sea water is not used, but there is some form of heat exchanger so tap
> water and antifreeze mix is used in the engine as per car practice.
>
> I certainly question the idea that a huge gpm figure is necessary for
> speed trials engine cooling. You're only running a short while, even at
> Bonneville, so the practice for decades has been, has it not, electric
> pumps like mine, and vented systems, so you just run down there, and
> heat your 10 to 20 or more gallons of water up gradually so that the
> run's over before boiling point is reached.
>
> I do agree that a thermostat makes complete sense, you get your engine
> hot enough to "go", but your cooling water is not hot, so you have more
> running time than if you heat the whole system up to some point.
>
> I think the expert Keith cited is right that the engine makes best power
> a little over 200, evidence for it is that the Japanese water-cooled
> motorcycles commonly use thermostats about 205 degrees. With 50/50
> antifreeze you have a boiling point way up there, 226 with no pressure,
> and higher with pressure. So no practical reason why you can't run 205
> with a speed trials iron.
>
> My Ardun worked fine with the 15 gpm pump, 180 degree thermostats, and
> 10 gallons in the system with a trunk-mounted tank, at Maxton last
> weekend. This may be a different matter than a SB Chevy with tremendous
> power output and smallish aluminum heads. The Ardun aluminum heads
> weigh maybe 50 pounds apiece and are thought to have a lot of
> AIR-cooling value from their sheer size. The bottom line is, a working
> system that gives you the endurance and running temperature you want.
> Cheers from ArdunBill in the Great Dismal Swamp, Chesapeake, VA
>
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