wayland1985

I'll be taking delivery of new heads in a few weeks. They should be upping the compression only to about 11.1:1 or so. Is there a need for a 160* thermostat in that case?

LS6427

iTrader: (2)

180 tstat is better than a 160......

.

wayland1985

Alright. Wasn't sure if the small bump in compression would warrant better cooling at all, or if the stock tstat would suffice

redbird555

iTrader: (14)

stock is 195 so 180 is still a drop. with a 160 i have noticed the car never really fully warms up past 170. some people like it that cold personally i dont, the 180 will keep it a little cooler but not too cold

LS6427

iTrader: (2)

Compression is meaningless. Unless you're building a high-revving 800 HP 13.5:1 compression race gas warrior......the factory cooling system can easily handle anything you can build up to about 650-700 RWHP N/A engine...with normal 11:1 to 12:1 compression.

But if you use a 180*F you will allow the coolant and the cooling system to do what its designed to do....which is to have the tstat close at the right coolant temp so the HOT coolant that just returned to the radiator for cooling....has enough time to remain in the radiator to cool....before the coolant thats in the heads and is AGAIN knocking on the door of the tstat trying to open it up to let that hot coolant out and into the radiator. With a 160*F the temp thats getting heated up in the heads reaches 160*F too fast.......now the tstat opens and the HOT coolant that was sitting in the radiator trying to cool off goes right back into the engine/heads.....

It starts a cycle where at some point the tstat will NOT close all the way........and now you have a big expensive water heater.......and it keeps getting hotter and hotter. The 180*F tstat allows more SITTING time for the hot coolant that just went into the radiator to cool off more.....

My 436ci stroker.....427ci stroker and now my iron blocked 390ci run cool as can be. The cooling system is just working properly. Most people with cooling issues have something thats just not right with the system......

.

RPM WS6

iTrader: (3)

Stock is actually 187°F (86°C, as marked on the bottom of the original factory t-stats), so the switch to a 180 is pretty pointless unless you just need a new t-stat anyway. But personally I'd rather have a 187 or 180 myself, vs. the 160, for the vast majority of applications and engine combos.

Generally I agree, at least in terms of t-stat selection. The t-stat temp is just a minimum setting, it doesn't guaranty staying under a certain maximum temp, so if the capacity of your cooling system isn't able to deal with the demands of your application and climate, then a cooler t-stat isn't going to help.

Having said that, for applications where the cooling system is adequate, some people like to use a cooler t-stat to allow for more aggressive tuning without detonation. I don't know how useful this really is though, as a hotter combustion chamber will be more efficient and generally make more power than a colder one; what you want is a cold intake air charge, not a cold combustion chamber. And that's the other most common reason for a cooler t-stat - to prevent intake heat soak. But this isn't much of a concern for for the dry, plastic intake of an LS1; it's a bigger concern when you have a metal intake and coolant running through it.

As for concerns with detonation due specifically to a compression bump, tuning and cam profile will play a big role in this as well. There really is no single static compression number that will/won't guaranty issues with detonation, other factors of your setup (and available octane in your region - some of us have 93, others only have 91) will be involved as well.

wayland1985

So it sounds like I'm fine with the stock thermostat.

dailydriver

I WISH I could get a 195* stat for the way these winters seem to be heading (I use my car right through the WHOLE year, NO MATTER what momma nature throws it's way).