Last summer I had to replace my stock water pump. I used the Stewart stage 1 pump and thermostat that I bought for my 350 Vortec engine I have waiting to go into my 91RS. I bought the 180* high flow thermostat that Stewart recommended. My problem is that when I drive the car on cold days it will never get up to 180* sometime 160*and takes forever to do it. When the weather is warmer it takes a long time to come up to 180* but does eventually get there. On hot days it will stay at 180* untill I stop or get into traffic, then the temp starts to climb. I have the fan on a switch which I always run when in city traffic. Temp will stay around 200* untill I run the a/c. After that in city traffic it will climb all the way into the red. All this on a stock 305tbi. I think I can solve the over heating problem when I fab up a fan shroud that will totally enclose the backside of the radiator except for the fan which will be moved back about an inch. My main concern is not getting up to temp like it should on cold or cool days. Thus the engine is running in open loop way to long. Anybody have any ideas?

Steve

 

Are there any holes in the thermostat? These will cause warm-up times in colder conditions to be pro-longed.

 

There are 4 slots in the thermostat for coolant bypass. I realize that this would cause a prolonged warm up but I never thought it wouldn't come up to operating temp at all. It's almost like running no t'stat at all when the weather is cold. I can always replace the t'stat with one that doesn't have bypass holes and drill my own but this is the thermostat that Stewart sold me. I just didn't want to tear up my water pump buy putting in a t'stat that didn't flow enough before it opened at 180*. I guess I'll wait for a while since the weather is starting to warm up.

Thanks Brody.

 

No problem. I have a Stewart Stage 1 on my car with a regular auto-parts store thermostat. However, I have drilled two 1/4" holes in it. In the winter (if that is what you call what we have down here) it is VERY slow to warm up, and might not even warm up at all on short trips. In the summer, the car warms up just fine. Heck, my water temp in the head was 130* the other day after sitting in the sun for 6 hours without running. Talk about a short warm up time...