Bextreme04
Full Access Member
- Joined
- May 13, 2019
- Posts
- 4,464
- Reaction score
- 5,631
- Location
- Oregon
- First Name
- Eric
- Truck Year
- 1980
- Truck Model
- K25
- Engine Size
- 350-4bbl
Not necessarily an exception, they just generally have more cooling issues. That's one of the reasons the Gen V & VI BBC have a different cooling flow pattern and therefore needs different head gaskets. It's also why the Gen VI has built in oil cooler ports, so that the engine oil can be pulled up to temp faster and kept at a reasonable temperature even under a heavy load for extended amounts of time. Having the engine cooler is almost always better for full throttle performance but has disadvantages that have been discussed earlier. These disadvantages are negated in full race vehicles because generally don't run under very extreme temperatures and generally run for much less time. The oil change intervals are generally much shorter and they aren't really asked to do more than one thing very well. A street vehicle needs to operate well in a wide variety of conditions and also for a very extended amount of time comparatively. Everything is a trade-off, so for a street vehicle it makes sense to sacrifice a few horsepower on the top end to stabilize the engine oil and transmission fluid under most operating conditions and also to allow the engine to run a bit more efficiently. The funny thing here is that due to how heat transfer works, the hotter your engine coolant is, less heat is pulled from the engine(once the thermostat is fully open) and MORE heat is transferred out of the radiator. So a thermostat that opens fully earlier will not necessarily allow the entire cooling system to function better, but might allow the engine to transfer more heat out and the radiator to transfer less. The engineers that designed the system most likely sized the radiator, pump, and thermostat temp to match as closely as possible so that the engine running at 100% throttle for 10 minutes or so will not produce enough heat to overcome the rest of the system.
When we have these old cars that we have made so many modifications too and that are using reman parts or upgraded speed parts, its almost impossible to match the system properly anymore. A good alternative is to just put the biggest, most efficient radiator you possibly can on it. Then you can size down the thermostat, get a higher flowing thermostat, or get a higher flowing pump to compensate for any issues with heat transfer through the engine. A cooler thermostat gets you better heat transfer out of the engine and the giant radiator compensates for the loss in thermal transfer from the lower temperature coolant. If you are running just a bit over stock power levels and have a clean, well tuned engine though, you will get more reliability and longevity from running a stock pump and thermostat and an adequate radiator.
lol. 
