Rock Posted April 20, 2014 Share Posted April 20, 2014 Ok guys need some help here. As you know I did some minor work on the motor, I changed out the manifold with an edelbrock a new carb,new headers and valve covers. Motor starts and run fine but it reaches above 240 degrees and need to shut it down. I assumed it was the thermostat and bought a new one but ran the motor without it and never rose above 180 degrees. I then tested the new thermostat and it opened around 190 degrees so I added it and tested again and of coarse it again rose to 240 degrees and I shut it down. I don't know what the problem could be.....it's like the thermostat doesn't open when installed. I don't see coolant flowing when the engine is running but the upper hose seems to get warm to the touch and the heater hoses steam......I don't know where to go from here....HELP Quote Link to comment Share on other sites More sharing options...
Rock Posted April 20, 2014 Author Share Posted April 20, 2014 I also want to add the water in the radiator is cold to the touch so assume the stat hasn't opened at all. Pretty sure I have all air out of the system. I do have heat in the cabin too. Quote Link to comment Share on other sites More sharing options...
dbreese Posted April 20, 2014 Share Posted April 20, 2014 ooops i'm late Glen, Sounds like you may have an air pocket in the cooling system. Take the rad cap off and crank the car and run the engine. When the engine gets to operating temp and the t-stat opens you should see water moving through the rad. also move y your heater control to hot on to make sure the air gets pushed out of the core as the coolant flows through. You may also try drilling a 3/16" hole in the t-stat flange to help bleed any air out of the system. Just some suggestions. David Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted April 20, 2014 Share Posted April 20, 2014 I always put a 3/16 hole in the flange of a thermostat if I am running one. When I am filling a engine with coolant I like to leave the thermostat housing off until I see coolant in the manifold crossover. Where is your timing at. If it is retarded it will build heat! Quote Link to comment Share on other sites More sharing options...
Rock Posted April 20, 2014 Author Share Posted April 20, 2014 9 degrees BTDC. So do you think it's still air in the system? I also elevated the front end about a foot off the ground.....I guess I could try the hole trick in the thermostat. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted April 20, 2014 Share Posted April 20, 2014 both Dave and Mike have it correct I always drill a hole in my thermostat too if there is a air pocket and the coolant isn't reaching the thermostat...it won't open Quote Link to comment Share on other sites More sharing options...
dbreese Posted April 20, 2014 Share Posted April 20, 2014 What are the spec's on your engine? If it has an aftermarket cam you may want to put in more initial timing. David Quote Link to comment Share on other sites More sharing options...
Gonzo Posted April 20, 2014 Share Posted April 20, 2014 It's possible you have a bad water pump also if your not seeing any water flow. Stupid question, but I am a mechanic and have seen it happen to the best, you didn't leave a rag or plug in any of the coolant passages did you ? Quote Link to comment Share on other sites More sharing options...
Rock Posted April 20, 2014 Author Share Posted April 20, 2014 The motor is a Mr. good wrench 350. Stock cam. I added an Edelbrock performer manifold, carb and rebuilt the distributor. New hoses and long water pump too. Quote Link to comment Share on other sites More sharing options...
Rock Posted April 20, 2014 Author Share Posted April 20, 2014 Coolant flows without the thermostat. And stays cool without one. Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted April 20, 2014 Share Posted April 20, 2014 Drill the hole don't look back! Quote Link to comment Share on other sites More sharing options...
Rock Posted April 20, 2014 Author Share Posted April 20, 2014 Lol.....will do sir. I will report my progress. It has to be air in the system......are these Montes hard to burp since there isn't a bleeder? Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted April 20, 2014 Share Posted April 20, 2014 Not really You may have some issues with the impeller on the water pump. Quote Link to comment Share on other sites More sharing options...
Rock Posted April 20, 2014 Author Share Posted April 20, 2014 The pump I bought was a long water pump and turns clock wise. I see the coolant flow without a stat. Quote Link to comment Share on other sites More sharing options...
Rock Posted April 20, 2014 Author Share Posted April 20, 2014 http://www.summitracing.com/parts/pro-67264/overview/make/chevrolet Here is the pump I bought. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted April 20, 2014 Share Posted April 20, 2014 as Mike said...drill the hole! Quote Link to comment Share on other sites More sharing options...
Leghome Posted April 20, 2014 Share Posted April 20, 2014 I put a stat in upside own once. LOL Quote Link to comment Share on other sites More sharing options...
wallaby Posted April 20, 2014 Share Posted April 20, 2014 Ditto the above. Most thermostats will let a small amount of flow happen even when closed, but I add a small hole to hasten the process and make sure the system can let air escape as water fills from below. It just makes me feel better knowing that there isn't a big air pocket trapped in there. it's important to recognize that the thermostat reacts to water temperature, and not to air temp...if there isn't water against the thermostat it won't open until the water gets super heated. I was surprised that the "upside-down" thermostat issue didn't come up earlier in this thread. It's a real common mistake and the thermostat seems to fit perfectly in either position. The sensor of the thermostat is the large copper pellet...that copper pellet needs to face the engine side so it sees the engine temp. There are several different types of thermostats for our engines, but they all have the copper pellet, usually with the temperature rating stamped on the end. That pellet end goes down into the manifold. Here's a pic. This shows the pellet side down as it should be: Quote Link to comment Share on other sites More sharing options...
Rock Posted April 20, 2014 Author Share Posted April 20, 2014 So I drilled a 3/16 hole in the thermostat and now it runs at about 220 degrees wich is a little hot in my opinion and I get a lot of foam building up at the radiator cap. Do you think I have a leak around the manifold? We put RTV around the bottom and top side of the gaskets..... And yes the pointy side of the thermostat is up and flat side inside manifold. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted April 20, 2014 Share Posted April 20, 2014 is that idling or driving it? do you have a clutch fan or a solid fan? Quote Link to comment Share on other sites More sharing options...
Rock Posted April 20, 2014 Author Share Posted April 20, 2014 is that idling or driving it? do you have a clutch fan or a solid fan? No clutch fan. The foam builds up while idling. And never seems to stop. A quick search suggests a leak. Quote Link to comment Share on other sites More sharing options...
MC-71 Posted April 20, 2014 Share Posted April 20, 2014 At this point I would play with the timing. You said you changed the intake manifold. The Dist. was out and reinstalled. I would try that. Don't go by OEM Specs. now because of the changes. A Vaccum gage will help you and your hearing. Good Luck. Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted April 20, 2014 Share Posted April 20, 2014 Advance the timing a bit and see what happens. Retarded timing builds heat in the head. You I am concerned about the foam. How much pressure does it build? Does it push water out with the cap on? Quote Link to comment Share on other sites More sharing options...
Rock Posted April 20, 2014 Author Share Posted April 20, 2014 Here's what it looks like...again it got too hot. Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted April 20, 2014 Share Posted April 20, 2014 Take the stat out again run it without it ans see if it makes foam. It seems like the stat is not opening. Quote Link to comment Share on other sites More sharing options...
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