05-09-2012, 09:23 AM
Just a quick question. After a few weeks I finally got around to mounting my Autometer Cobalt guages in my 78 Malibu. One thing I noticed is the temp goes up to 200 degrees and stay there as long as me twin Spal fans are running. A little variation on the street, but not much. I still run the stock 195 stat that was in the water pump when I pirated it of the 03 1 ton van I took the original 6.0 out of.
Do these LS engines like higher temps or would I must likely see a power advantage by lowering it to say 160 degrees or just gut it so I can use the factory O ring GM gave me? I put quite a few street miles on the new 402 stroker last friday and no issues that I could find.
05-09-2012, 11:44 AM
I am also curious about people opinion on this. I am running a 160 thermostat and my engine never kicks on the fans and never gets above 180.
I was concerned I am running too cool.
05-09-2012, 01:26 PM
For one, it depends on the completer cooling system, for example:
My 89 RS, 6.0, stock 89 radiator, stock fan, also has a small 12 inch pusher opposite the stock fan, and has a 165 stat, always runs 170ish, even in Texas heat, it does fine all day, till i beat the snot out of her, then she will climb to 185ish, and come on back down, rarely it will be so hot as to stay 180ish because of blistering heat.
The 86 TA i have, wit a stock radiator on the 5.3, runs great with a stocker i drilled 5 holes in, but it is a 3 speed and continuous use at 2500 RPM will make it go from the 170ish temp to 195 and even climb to 210, but that is a stock fan with no assistance from a pusher yet, and the t stat is BS modded, may work fine with a 160?
The 94 GMC with the 4.8 has a stocker 195, runs there all day, beating it in any weather with the stock radiator and a stock clutch fan setup, much beefier radiator than the third gens and the clutch fan moves allot of air.
Now, with my cars being 7200 RPM screamers, i like the lower T stats, for my 94 beater truck, i drive it anywhere and any time, and as usual, a chokeless 750 carb, runs funny till it gets warmth, so the higher factory stat shakes off any cold weather activity very fast, unlike the 165s that take a bit longer and have cams so it is really not warming quick enough.
So, per application, anything spinning over 6000, and has a cam, will see abuse over 6500 many a time, a lower stat is great as the lower engine temps also allow the intake to be cooler, cooler intake charger is usually more efficient power.
This is all my opinions and experiences speaking, but i hope it helps.