TBI 350 thermostat question

[DaveB]

The commando project seems to be running hotter than I expect. When it is warm the lower radiator hose is quite a bit cooler than the top hose which makes me think the thermostat may not be doing its job. After doing some checking online I see thermostat temperatures listed for the TBI engines from 160, 180, 192 and 195. Anyone know what would be the best value ? The TBI setup came from an 88 suburban if that matters. The temp gauge in the block is reading around 210 and the top hose is under pressure before I shut it off.

 

[mbryson]

Mine runs right around 200. I think I'm running the stock 192* for my '89 Suburban.

 

[bryson]

I have had good luck with 195*ish, but I have also drilled 5 or 6 1/8" holes in the t-stat surround. Drilling the holes in the t-stat has been suggested to me my more than one engine builder, and it seems to help a fair amount.

 

[Tacoma]

Mine have all run at 210 on the admittedly imprecise stock GM gauge. Thermostats were 195ish, as per the factory manual.

My current Burb keeps running wicked hot for a minute, and then suddenly dropping temps, so either I've got a funky thermostat, or an air bubble from the swap. I may drill some holes today. Usually happens after startup, but sometimes going down the highway, which makes me think bubble.

 

[neagtea]

I have heard of guys restricting the flow to the heater core and it helping out. I also use the high flow stat I can't remember off hand which brand, or just gut the stock one and use it for a restricter. The warm up time is fast enough it shouldn't be an issue.

 

[Jinx]

Dave,
I run a 195* in my TPI 350 per stock recomendations, but I have to tell you make sure your gauge is working. I chased an "overheating" issue for a couple of weekends until I found out my thermostat wasn't proper grounded...

Funny when grounded, the gauge read 25* cooler...

 

[DaveB]

I'm pretty sure the guage is grounded and reading correct since I have used an electronic temp meter to read the case temp on the sending unit and the surrounding head surfaces and it matches the guage. I plan on pulling the thermostat and checking it out to see if it working.

 

[Max Power]

Don't quote me on this, but I have heard of some guys bypassing the thermostat all together.

 

[Tacoma]

On TBI engines, if it doesnt see something like 200*, it stays in closed loop. Not good.

 

[thefirstzukman]

On TBI engines, if it doesnt see something like 200*, it stays in closed loop. Not good.

195* although you can get a chip with program for other temps..

Drill a hole or 2 in the stat... Helps purge any air in the system, some will actually come with a hole in them.. If there is a air bubble against the stat it won't get hot enough to open. I always drill the holes in the Chevys, have for years, works great..

 

[DaveB]

I picked up a new thermostat with the bleeder hole already in it and it works much better now. The old one had a rough spot that must have been keeping it from working properly. I heated it up with a torch and it did open but it was quite warm. With the new thermostat the temp gauge stays around 195 and it will wander up to 200 and then drop back down. The top radiator hose isn't under a bunch of pressure either.

 

[cheepin]

I have a stock 195* t-stat it will run up to 205* then the fan kicks in and it drops to 195*.I should try the drilling the hole thing.I have noticed it getting warm when first fired up but will drop when I rev it a touch.