How hot is too hot?

We had a couple 100 degree days here in Southern California and my truck was hovering right at 200 degrees.

Electric fans running constant.

Even on the freeway it still was right up there. I expected it to drop slightly, but it didnt.

Whats normal?

Thanks guys.

My 64 impala runs around 200 all the time.

Pulleys?

maddog said:

We had a couple 100 degree days here in Southern California and my truck was hovering right at 200 degrees.

Electric fans running constant.

Even on the freeway it still was right up there. I expected it to drop slightly, but it didnt.

Whats normal?

Thanks guys.

Click to expand...

Maddog,
A culprit can be your crank pulley & H2O pulley sizes. Did u put a smaller crank pulley on for clearance? What size is that pulley & what size is u're water pump pulley. Also, what size is u're fan/fans? This is a problem here in H-town because it is a really hot mother here & especially in the summer! I use Spal 16" fans / 2350 cmf & my cars will sit @ idle forever in 100F + weather @ 185F but I do run cheap alum radiators I buy off da Bay.

BoB

my truck gets up to 200 or 205 if i sit in traffic on the 110 degree days we get here during the summer. It's pretty rare and it hasn't done any damge yet. any higher though and i would freak. If it's running like that all the time, i would check things out, but if it is only on super hot days you might be ok. Personally though, i can't wait to upgrade to an aluminum radiator.

Alum radiators

joehalford01 said:

Personally though, i can't wait to upgrade to an aluminum radiator.

Click to expand...

Halford,
I bought several off ebay from places that had lots of feedback & have been very satisfied. They kool like a dream & look kool too. Last year it was over 100 every day for over a month & I had no problems. I did have to change the pulleys on my Chevelle because originally I put underdriven ones on to "supposedly" gain HP but it heated up @ idle so that had to go!!!'

BoB

i've been looking around for awhile, just havn't done it yet, you know how that goes......

Tripper said:

Maddog,
A culprit can be your crank pulley & H2O pulley sizes. Did u put a smaller crank pulley on for clearance? What size is that pulley & what size is u're water pump pulley. Also, what size is u're fan/fans? This is a problem here in H-town because it is a really hot mother here & especially in the summer! I use Spal 16" fans / 2350 cmf & my cars will sit @ idle forever in 100F + weather @ 185F but I do run cheap alum radiators I buy off da Bay.

BoB

Click to expand...

So I should measure the diameter of the pullys from where? The O.D.?

The 2 electric fans are 11" I think (maybe 9") OK, I dont know but I will measure them. I mounted them on an aluminum shroud.

What is so special about aluminum radiators?

i'm not sure on the pulleys, but a note on the shroud, does it encompass the entire side of the radiator? The fans will really only cool the space they are directly on and the shrouded sections. So if you have an improper shroud, i would check into something else. Also, you might do better with one large electric fan. New ones are pricey but the mid nineties ford tauras had a great fan and shroud and can be had for cheapo at the local junkyard. It seems unlikely that a four banger 90's car fan could keep a big v8 cool but just take a look at the grills on those suckers. there pretty much isn't one, they needed a really good fan to suck air through that tiny grill and keep it cool.

As far as aluminum, it dissapates heat better. thats it, just the material itself.

dog,

You might want to take a look at this site:
http://www.evanscooling.com/index2.html
I've never used it, but have heard good things about it.
You can't mix water or antifreeze with it, it's like a propylene glycol or some thing and it doesn't boil till like 375 degrees.
Doesn't corrode and will not put a electric charge in the system like antifreeze does. I believe it also only requires running a 7lb. cap which puts less stress on hoses and no use of a thermostat.

Jeff

Rows!

maddog said:

What is so special about aluminum radiators?

Click to expand...

Maddog,
Besides the heat dissipation with alum, the rows are twice as large as the standard copper tubed radiator. A two row alum rad is the same size as a 4 row regular copper one. I have been told that is because copper is not sturdy enough to made the tubes that large. All I know is that it really seems to take care of business. Your set up sounds pretty good though. Shroud... 2 11"ers. That really should do it. Check on those pulley sizes & let me know. When I had that problem though, once I got rolling mine would go back down to 185F. HAd that same problem on a LUV truck I slammed a 327 in too. Oh yeah, pulleys r probably measured by OD.

BoB

Consider this. Most of todays cars run at 200 degrees or higher. The reason for this is because most internal combustion engines are only about 30% to 40% efficent. The higher you can run an engine at a CONTROLED heat, the more efficent it is, (better gas mileage).
I altered my Chevelles cooling system to maitain 195 to 200 degrees. It runs cleaner at idle.

As long as you can control your heat range, 200 is fine. The old thought of 185 being the perfect temp. is misunderstood. Most engines make peak power at or around 185. That's where that line of thinking comes from.
but engines are not the most efficent at this temp.

The reason engines will run hotter with smaller crank pullies is because the water pump pulley is turning slower than the smaller crank pulley. So water is being flowed at a slower rate.

Look at your cooling system this way.
If it's running hot at low speeds or sitting still, than it will usually be insuffencent airflow. Good fans from SPAL and complete shrouding of the rad. will more than likley cure this.
If it cools at low speeds, but heats up while running down the road, then it's probably water flow related. You are more than likely running water to fast through the system.
You can install a smaller crank pulley, (which may make low rpm cooling suffer), or install a restrictor to slow down water flow.
But, I have seen some cars need to move water faster at highway speeds to cool properly. This has to do with how efficent the rad. is. (Alum. verses copper/brass).

Alot of people think all you need to do is throw on a rad. and a water pump and your done. It doesn't work that way.
The cooling system is just as important as a good intake and carb. combo.
They need to be "tuned" to work at their best potental.


Tracy

Lots of very good points.

As far as the pulley size goes, it should be measured where the belt "Rides" at. Don't forget to leave room for belt adjustment and belt stretch as well.

Sure is a good string of engine cooling and heating information here.

Just what I expected from you boneheads ( not to be confused with the one and only Bonehead )

Thanks a lot guys.