Re: Radiators...whats best?
Riddle me this:
My Blazer had a digital dash. It always ran on the "200" bar. Each bar was appx 20ºF. while the exact temp is not discernible, the repeatability of the indications was very consistent.
While driving in low temp ambient of perhaps 45ºF or lower, using the heater, the temp gauge would increase one bar. Ie, the engine ran 'hotter' using the heater in ~45º, than it did in 85º ambient using the A/C. If I turned off the heater, the temp would go back down one bar to 'normal'. Turn the heat back on, and about one minute later, the temp was back up.
Why?
Edit: The purpose of this post is to get ya'll to think about heat-load under various conditions as related to radiator capacity.
For solving the riddle, the Blazer's cooling system layout is identical to SyTy. But the gauge sending unit is on the Driver's side head on the Blazer. It's on the Passenger side head on a SyTy. Happy Thinking.
I would reason its because your pulling heat out of the engine using the heater. This shows a lower coolant temp to the thermostat causing the thermostat to close more.
Because the heater core pulls heat out before the thermostat, essentially unregulated, this changes the overall thermodynamic efficiency of the system and in this case creating lower lows (the radiator is colder) and higher highs (the engine is warmer).
As for the corvette radiator, it looks to be an 84-89 (another source said 86-88). As for why its more efficient I couldn't give you exact details as I have not dissected both of them (or either of them). But, as with any heat transmitting device there is an inherent efficiency in it. My guess is the Corvette radiator is of a different design that allows a higher efficiency with less thickness. Yes, yes, I know we were already discussing this. I just offer that a radiator that is 3" thick yet only has 4 1/8" tubes running from one tank to the other is going to have a low efficency, but a radiator that is 1" thick but runs oval cross tubes that are as wide as the radiator is "thick", this allows maximum heat to be transferred between the cores and the fins. Between the S-Series and the Corvette, which do you think that Chevrolet is going to spend money on trying to get the best performance?
Anyways, I hardly have conclusive facts between the two, all I know is the Corvette radiator is/was the preferred choice for budget V8 swaps. You did hit on one point though, its thinner, and in the cramped engine bay of a V8 s-10 having room for a good fan could make all the difference.
As for seeing 230 towing with the blazer, sure, it makes sense. Thermodynamics dictates that the amount of heat transferred between two objects is related to their difference in temperature (radiator and ambient air in this case). As the engine gets hotter the radiator gets hotter too and is able to transfer more BTU's into the air. Plus the thermostat is full open and the fan clutch is fully engaged, although I have a hard time believing that the stock fan would be able to "pull" more air than 55 mph would shove down the radiator, even if the engine was spinning 4500 RPM. Lots of variable in that discussion though. BTW, is this Blazer temp gauge better than the Trailblazers? I know there was a 20-30 degree swing in engine temp on those that wouldn't result in an change in the temp reading (verified with scan gauge). That dang thing would go dead on middle even if the engine was 190 or ~210. GM effectively turned it into a "warm fuzzy" indicator.
