thermostats

[socor7]

I am currently running a 180 temp stat, nothing wild. but I was wondering if they make a faster reacting stat. There are times durning warm up where the temp will rise to over 220 before it opens and then the temp just drops, I have a new water pump and 2 core aluminum radiatior. so I know the cooling system is all new including the temp stat. after it opens, the radiator cools so well that it will actually close off again and my temp will run back up to 220 or so. I flucuates like this acouple of times, and them if finally settels out about 175 or 180.

any ideas on how to remedy this flux in temp. I am afraid all the heating and cooling will hurt my new gm motor.

Thanks

Drew

[Vettefan87]

The Tstat should open no later then around 187 or so. I would first make sure you don't have any air pockets in the system, then if you don't I would buy a new 180 Tstat. You can also put a 160 Tstat in there too. That is what I have in my 87.

[socor7]

Well I know for sure that there are no air pockets in the system, I have had it full for weeks now. I know that this is a brand new t stat. The 160 will not help a whole lot. because my system only stay at 180 or so while driving, but the stat is like a 5 dollar part and a 160 should open up sooner then the 180 stat.

Is there any temp that would be to cold, if my system could keep it that cool?

[AKRAY4PLAY]

you nailed the problem, cool water sitting around the t-stat and keeping it closed. easiest fix is to pull your t-stat and drill a 1/8" hole in the plate. this will allow a small amount of flow to move heat to the t-stat. constant flow = more evenly distributed heat. hope this helps, Brian.

[goertz]

something is wrong. there is a waterpump bypass hose not connected to the correct place, or something else. the factory installed system works great, and you should not have to drill holes in the t stat, the bypass should do that on it's own. i'm thinking maybe it's blocked off, or something along those lines.

[JohnZ]

You don't need to drill holes in the thermostat - you already have a thermostat bypass circuit between the passenger side of the water pump and the block, and the heater circuit also functions as a bypass.

Get a 180* Robertshaw #330-180 balanced-flow thermostat (also re-packaged and sold by Mr. Gasket); calibration is more accurate than the generic parts store thermostats, you won't get the "cycling" spikes, and if they fail, they fail open, not closed.

If you had a cooling system that was capable of maintaining temp at 160*, that's too cold; won't allow the oil to get hot enough to boil off condensates and blow-by contaminants, which make the oil acidic and tends to form sludge.

[socor7]

yah well every thing is hooked up the same as the previous motor. and the intake is recomended for the gm crate engine I purchsed. I just think that the t stat is wrong. I will try a new one, a robertshaw one thanks for the info.


Drew

[RodsnRides]

The Robert Shaw 330-180 is good for me, too. I also note the Mr. Gasket part change. Yes, it does work.

Also suggest Red Line "Water Wetter". They say one bottle, but I have run 2 and do slow city traffic well (.030 motors-cannot comment on bigger bore).

7-blade fan-good. Tight fan shroud-wave a rag in front of the radiator-look for "pull". Discovering these electric fans are pretty good as well (I'm old school).

If you have the thermostat out, pull the block drain plugs and give it a good engine flush-regular garden hose will do. Take the heater hoses off and flush the heater core backwards.

Finally, look at the radiator, and the fins (bent?). 2-core seems small-given low speed airflow in heat. Perhaps an air gun to blow the bugs/dirt out backwards.

Good luck-hope this helps.

Rick

[socor7]

it is brand new from dewitts it is a 2 core alum and keeps my car at 160 the radiatior is fine, it is the thermostat. it is the t stat that will not open soon enough so it runs hot then the alum does its job and brings it right down to 160 which is tooo cold for the t stat and it closes thus I get a sea saw effect open close open close open close then it finally balances out.