Technical What Temp does your open engine get?

I have a 1949 Chevrolet Modded with and open engine, I am running a 160 thermostat and electric fan. I am running at between 180 and 200 most of the time, is this normal? My question is what is too hot? I've read several threads on here about the correct temps you should run. Just curious as to what other open car engines run in the summer times. I don't want to be out running around and run hot. I'm thinking about going up to a 180 to keep the water in the radiator longer for a better cool down. thoughts?

 

180 to 200 is perfect.

 

Spunds like your in the normal range to me. Remember, keeping the water in the radiator longer also keeps the water in the block longer. Get my point? If your worried about overheating take out the thermostats.

 

Functioning thermostats don't make engines overheat.

 

I understand your comments but If the water travels too fast through the radiator, it will not dissipate the heat either. I have heard that open engine cars run hotter because we don't have shrouds, fenders or hoods to keep the air around the engine. I am concerned because it is 80 in Georgia now and I am already running 200 degrees, will it get worse in the 100 degree days?

 

Am I missing the obvious? What kind of motor are we talking here?

 

Chevrolet 350, aluminum heads, 11:1 compression, 750 Holley.

 

From what I understand about thermostats is if you have 160 in then temp should stay around that temp if the rad is big enough.I believe 160 is to cold,180 to 200 like squirrel says!! Try a 180 stat to see if it holds 180. Pete

 

The conventional thinking is that a 160* thermostat will make the engine run at 160-170*.
The actuality is that a 190* thermostat keeps the engine at a comfortable 180*.
A thermostat's less than $10, at your local auto parts store. Recommend you try it.

 

That is the information I was looking for. I am adding a polished water pump this week and will go up to a higher thermostat at that time. Thanks

 

If you really have 11:1 compression and are running pump gas, the only way to keep detonation from destroying the engine is to retard the spark, which WILL cause overheating.

 

Our flathead runs 180 degrees, all summer long.

 

That's not going to help -

In this case, he has a 160 thermostat, but runs a 200.
That means the thermostat is already open and apparently the engine is generating more heat than the radiator can shed.

There's a few things to look at
1 st is the engine tune- makes sure its right.
2. Coolant flow thru the radiator and size of the radiator.
3 airflow thru the radiator , shroud will help a bunch
4, hydrometer test the coolant. A 50/50 mix has Freeze protection down to -58* at the cost of 30% less efficient transfer of heat out of the coolant. Not a big deal in the winter but in the summer you'd really want that 30% back no? A 75/25 water/coolant mix will get you enough corrosion protection and lubricants while drastically increasing the ability of the coolant to shed its heat.

 

Check your radiator. Touch the center of it and see if its colder than it is around the edges. If it is then its partially clogged.

 

Here's what's going on here - your radiator is too small for a 160* t-stat to operate correctly in your application. If you're running between 180-200 all the time, that means your t-stat is never closing while the engine is at temp. This is a dangerous situation because it will eventually reach a point of no return where it will suddenly overheat. The thermostat needs to cycle opened and closed in order for the coolant in the radiator to be cooled off. If it never closes then the coolant doesn't spend enough time in the radiator to be cooled off. Sounds to me like you're running right on the edge of a serious problem. You should try putting a 180* t-stat in it and see if that helps stabilize the temp closer to 180 - it may. If you still notice it running hotter than 180, move up to a 195. If that doesn't help then you may have to look into getting a larger radiator.

Edit: If your cooling system is operating properly your engine temp should never fluctuate more than about 10* or so. It should also run closer to 180 than 160...160* is really too cool for a street driver. It works for making power, but it will wear out your engine sooner. 180-195 is best for longevity.

 

Mechanic 58 is dead on the money, except I'd go with a 195 to start, 200 is NOT HOT for a 350, it should run around 200 for it to run best. A hotter stat allows the coolant more time in the rad, a colder stat pops wide open, the coolant rushes through the rad not getting enough time to exchange heat and gives you cooling problems.

 

Are you running a vacuum advance hooked to manifold vacuum,it will make run cooler.

 

I will go up to at least a 180 temp stat this week and see if that helps, I have a car show 45 minutes away so that should show me anything else I may need to do. Thanks