Re: Hot water testing of the parallel and stock IC.
cavitation is a function of many variables, your question is best answered by looking at the vapor pressure of the mixture you wanna use. The fluid boils when the pressure falls below this vapor pressure. The pump has very high shear forces on the fluid, which is how it pumps, this is where the boiling would be most significant.
The series 30 pump would be more powerful and more likely to cavitate. My pet pump the 90 would be WAYYYYY more susceptable to this, but I will be running it at about 1/2 the typical rpm. THiis should work fine as the larger impeller would have less boiling potential.
I have to see the resulting cavitation in the stock IC at the 2 to 4 GPM flow rates ( gotta man up and do this again ). The burning question that I have to quell, is exactly how much static pressure is required to prevent unwanted boiling. My water heater was only about 125 F degrees, the water in the IC may be a bunch higher especially on the edges of the water tubing. Think about under hood temps.........
Woody