Hi Guys, a Buick newbie here, in the process of cleaning up my 401 for the 65 Riviera I just got, I found under the valve covers plenty of gunk. In the old days we ran the coolest therostat we could find thinking that would help keep the fuel mixture temp lower and make more power. Later I read that keeping the heads that cool on a street car would lead to cooling off the oil in a manner that lead to crud buildup on valve springs and rocker arms. Also understand that unleaded fuel required higher temp thermo stats. I found a 170 degree in my nailhead and was wondering if a 195 or 180 temp would be better.........any thoughts on this matter............
Running a 180 would be fine. I still run my motors a little on the cool side when I can. This helps slightly to reduce ping from the gas we run these days. Most engine builders will tell you engines make more power hot (up to about 215-220 degrees) which is like the new cars run. But I still run crummy old radiators and do not like to cook the oil or the accessories attached to the engine. It is kind of a 'my friend says' situation. I would not run higher than a 180 t stat though. Remember, the car was not engineered to run hot like the new cars do.
I run a 160 I just went form 180 to 160. Helps open up early on those hot days. Today I hit 206 on the freeway in 80 degree Minnesota weather in my 66 Skylark GS. Keep em cool!
I run a 160 with a 4 core radiator and have never had any problems. Skylarknut is right - "keep em cool!" -Paul
I use a 160 and never run over 175 degrees. I am debating if this is a good idea. The plus side is I can run a lot of advance with no ping problem, oil pressure is better and the automatic transmission runs cool. The negative side is make sure you do a good warm up(should do that anyway) you may have a little piston skuff, and loss a few HP. Not many can run that cool. I would run a 170 thermostat if I could find one.
