How hot is too hot?

[brads70]

Having a minor issue with heat. I just installed a triple pass rad and its still creeping up to 205F in medium stop and go traffic.  I got home shut it off and got out my temp gun and it reads 10 degs cooler than the autometer mechanical gauge shows?  The temp gun is a cheap Princess Auto ( like harbor freight in the USA) so I don't know just how accurate it really is? Temp is 180 on the hwy which is perfect. Just worring about long lines at the border crossing, last year it was 1 1/2 hour just sitting.
Maybe drop the timing a little? It's at 36 now?
At what temperature should one REALLY worry, and shut it off? 230F?

[Strawdawg]

That is where modern cars run normally so it's not too hot.  It might make detonation a little more likely if you were beating on it.

I am sure you already have one, but, a multi-pass radiator needs a good high volume water pump and a high flow thermostat in order to keep good flow velocity thru the core.

Beyond that, it is a question of air flow in most cases...particulary if it runs cool on the road.   The other factor is the percentage of coolant you are running.  High percentages don't cool very well compared to lower doses.

[brads70]

That is where modern cars run normally so it's not too hot.  It might make detonation a little more likely if you were beating on it.

I am sure you already have one, but, a multi-pass radiator needs a good high volume water pump and a high flow thermostat in order to keep good flow velocity thru the core.

Beyond that, it is a question of air flow in most cases...particulary if it runs cool on the road.   The other factor is the percentage of coolant you are running.  High percentages don't cool very well compared to lower doses.

Thanks for the reply!I have the Milodon W/P  , Just changed the coolant added one gallon of antifreeze, one bottle of "purple ice" then filled it up with water. Using the HHR fan which sucks a sheet of paper to the grill pretty good when it's running?

[cudabob496]

going to only 20% antifreeze lowered my temp by 10 degrees


and of course, I'm a big fan of aluminum radiators.

[brads70]

going to only 20% antifreeze lowered my temp by 10 degrees

Thanks for chiming in! I read that in another post you had!    My issue is I live in Canada and don't want to change the coolant 2 times a year

[cudabob496]

Thanks for chiming in! I read that in another post you had!    My issue is I live in Canada and don't want to change the coolant 2 times a year

My plan:

I just siphon out the radiator, 2 gallons, into some milk jugs.
Set jugs aside.
Put in 2 gallons of pure water.
In winter, syphon out 2 gallons, and
poor in the 2 gallons that were syphoned out at beginning of summer.

check final concentration with a $6 device, and adjust accordingly.

We have about 4 months of plus 90 degree weather potential, so I don't mind the small hassle.

[Sonnythebull]

Vent that hood. Made a huge difference for me. 205 in traffic ain't bad on a super hot day especially if running AC

[brads70]

Vent that hood. Made a huge difference for me. 205 in traffic ain't bad on a super hot day especially if running AC

 It was somewhat  hot today ( 87F) and the humidity was worse ( over 80%)
I don't have A/C 

[cudabob496]

personally I would not be comfortable over 200 degrees with iron heads.
Too much detonation potential, especially if you kept your foot
in it for a while.
Alum heads almost prefer it, since they remove heat better, and it helps
keep cylinder pressure higher.

[brads70]

personally I would not be comfortable over 200 degrees with iron heads.
Too much detonation potential, especially if you kept your foot
in it for a while.
Alum heads almost prefer it, since they remove heat better, and it helps
keep cylinder pressure higher.

I have aluminum heads  so here's to hoping it makes it to Carlisle alright!

[Strawdawg]

Thanks for the reply!I have the Milodon W/P  , Just changed the coolant added one gallon of antifreeze, one bottle of "purple ice" then filled it up with water. Using the HHR fan which sucks a sheet of paper to the grill pretty good when it's running?

 

With one gallon, I don't think you are running too much coolant.  Your situation is a bit more dicey because the temperature is far more volatile than most of us that live down here.

I don't remember how much over bored you are on the last engine you built, but sometimes a good overbore, a little core shift, and suddenly you get one that runs hotter than you would expect.  I don't think I would be concerned at all.  You are not going to turn the timing up to 38 degs and go road racing when the car is that warm anyway.     If nothing else, you will get better gas mileage!

I think the HHR probably pulls a lot more air than most of these cheap aftermarket fans that advertise big cfm but don't pull it when placed near a radiator.  If you have not, hot wire the fans to the battery/alternator and turn them on with a relay so you get full voltage to them.  Get enuf voltage and you will suck the license plate off the car in front of you.

[74 challenge]

Fan shroud?

[bad440]

You should also check out waterless coolants, much higher boiling point, zero corrosion, etc. run it in my 440 with great success using factory 3 core radiator.

[brads70]

Fan shroud?

HHR fan has a built in shroud

You should also check out waterless coolants, much higher boiling point, zero corrosion, etc. run it in my 440 with great success using factory 3 core radiator.

Cool stuff first I've head of this , Thanks! 

[HP_Cuda]

This is why I'm going 4 core Aluminum radiator.