How hot is too hot

[Sammy]

Personally I removed the thermostat as I get nervous anything above 210 as it stays garaged below 40 in the winter. This is another reason not to bore a block where the water jackets are so thin. I like the added thickness on the block. I hear 50/60 over all the time, I cringe.

[leddzepp]

Originally Posted by haysonj

We are having 100 degree heat in California and I drove to LA yesterday. In heavy stop and go traffic my temp went up to 220 and stayed there. I have electric fans and a high flow water pump with a 195 degree thermostat. Also have a new aluminum radiator. Is 220 too hot for an extended period of time.

Next question...are you using a fan shroud?

[69long"n"low]

ive always been worried about this i run a 160 thermostat and no shroud and in traffic on an 80 degree day it get up to about 200. ive been thinking about goin to electric fans but will they help to keep it cold and can i still use my engine fan with them

[LONGHAIR]

Also (though I have never tried this, just something I read somewhere), running with no thermostat can let the coolant circulate too fast -- that is, it isn't in the radiator long enough to cool down, and returns to the engine... continually getting hotter. As a result, you might actually run hotter with no thermostat than with one. True? I dunno, maybe someone here has had it happen...

That is true. The thermostat also serving as a flow restriction. Even in racecars where warm-up speed is not an issue, they use a "restrictor". It is nothing more than a washer that fits in the thermostat's place. They are usually sold in kit form with a few different sized holes. Then you experiment to determine the one that works best in your case.

There was just a big thread about this very subject about a week ago.

[leddzepp]

A shroud is the best thing you can have to improve your cooling efficiency. You can have a powerful electric fan, but without a shroud to "force" the air through the radiator, it just takes the path of least resistance around the radiator.

[ed2552]

Originally Posted by 69long"n"low

ive always been worried about this i run a 160 thermostat and no shroud and in traffic on an 80 degree day it get up to about 200. ive been thinking about goin to electric fans but will they help to keep it cold and can i still use my engine fan with them

No, it will not fit, if you want elec. fans, build a shroud out of some sheet aluminum and a good fan, Spal, flex a lite, etc and it will stay cold. Make sure that it is spinning the right way, pulling if on the back of the engine, otherwise it will push the air coming in back out again. Early classic builds an electric fan kit for our trucks with the stock rad, so that is an option, too, and it has a pre-made shroud

[ed2552]

Originally Posted by leddzepp

A shroud is the best thing you can have to improve your cooling efficiency. You can have a powerful electric fan, but without a shroud to "force" the air through the radiator, it just takes the path of least resistance around the radiator.

unless it is right up against the radiator

[haysonj]

I have duel electric puller fans that come on 50 % at 195 and 100 % at 210. they are sealed to the inside of the radiator. they also have two flap seals that will allow air through when you are moving. As to the T-stat my truck actually ran hotter with the 180 T-stat then the 195. I think because the high flow pump would pump the coolant to fast with the T-stat wide open and not allow it in the radiator long enough to cool.

[72lb4x4]

Another consideration is how hot is the oil and at what temp does it break down. One of the claims for synthetic oils is that they can survive higher temps than conventional oils.

[El Jay]

Originally Posted by HoupPhotography

Then why use one at all?

It also puts a little back pressure on your water pump to keep the block full, preventing "hot spots."

[WorkinLonghorn]

Another factor in play here (that I always forget because I've only had manual transmissions for years) is that if you are running 250 deg. then your automatic transmission will also be running hotter and higher temperatures excellerate clutch,band,and seal deterioration.But with a stick,I don't worry.
Any of you guys running str8 water,or a weak dilution of antifreeze because of leaks or just cheapness,expect to have overheating probs,a rusted out engine,and failed water pumps as a result!

[Stocker]

Originally Posted by LONGHAIR

There was just a big thread about this very subject about a week ago.

Ahhh, I missed it. How embarrassing...

[Ole Blue 68]

Originally Posted by haysonj

I have duel electric puller fans that come on 50 % at 195 and 100 % at 210. they are sealed to the inside of the radiator. they also have two flap seals that will allow air through when you are moving. As to the T-stat my truck actually ran hotter with the 180 T-stat then the 195. I think because the high flow pump would pump the coolant to fast with the T-stat wide open and not allow it in the radiator long enough to cool.

You're exactly right regarding the t-stat...I found that out the hard way when I decided to run a 160 t-stat mistakenly thinking it would lower my cooling temp. Wrong. Wound up hotter than ever.