Is this too hot?

[AUSSIEVETTEMAN]

I know this subject has been covered in quite a few forums, but how hot is too hot?

I have just recently changed the thermostat from a 195 degree to a 180 degree in my 81 Coupe here in Australia. The old girl starts in the morning, gets to around 180+ and the thermostat opens and she sits on 180 all morning.
On th highway, she sits between 190 and 195 degrees depending on what type of car is in the challenging lane, but in traffic that changes in around 15 minutes to 210+.
Hottest is around 225, but we haven't hit summer yet.
I have also changed the radiator cap from the 13 PSI one that was on there from the previous owner, I know it was supposed to be 15 PSI, to a 16 PSI cap. At least the system is under the right amount of pressure now. Glycol mix is 50/50.

What do you guys suggest?
Do you think she is running hot?

I am thinking of flushing the entire system including the block as the radiator was recently done, but the shop that did it never touched the block.
I'm thinking of then changing both radiator hoses (top & bottom) and having the radiator core flushed or even recored.
Do you think a new radiator is needed?

I would hate to see a matching numbers car's block be cooked! :cry

We need to sort out any probs before the Gold Coast Indy as our club is supplying 50 Vettes to Indy for the Driver parades on the Saturday and Sunday. It would be very imbarrasing to have a heating problem on the day, especially if it is televised internationally!

Thanks in advance for any tips you guys can give.
I'm scratching my head on this one! :duh

Tony

 

[cruzer99]

Flush the rad and check for any air blockage. That is a little to hot. I would expect 180-200 as normal if everything is functioning as normal.
Rad will collect a lot of junk and even some roo's.
Good luck, wave and we will be watching.....Good on ya and G'day

 

[AUSSIEVETTEMAN]

Thanks

Ron,
The car is lower than most cars here in Oz, so the roo's can't figure out wether to get out of the way or jump over the top!

Thanks for your feedback.

Cheers
Tony

 

[JohnZ]

I'd flush it and either have the radiator re-cored or replace it; highway heating is almost always the radiator, assuming your lower air dam is in place and the lower hose isn't collapsing.

If you re-core or replace the radiator, make sure you get a core with AT LEAST the same cooling capacity (heat rejection) as the original, not just one "that fits".

The new radiator cap is a good idea for sealing the system, but it has nothing to do with operating temperature; it just pressurizes the system in order to raise the coolant's boiling point to raise the temperature at which it "pukes" (a 50-50 mix at 16 psi won't boil until about 268 degrees F).

 

[jetech]

Hi Tony
My 77 was running hot (220 t0 240) when I got on it or was on the highway. I added 1 1/2" to the height of the lower spoiler using aluminum sheet. While I was bolting the extension on I noticed that the right fender well liner had about 8" missing from the lower front end. I think this dumped most of the air pressure that the spoiler built up allowing the air to bypass the radiator. I riveted a patch over the missing section and now my temp stays around 200 to 210. Check your wheel well liners, if they are ok maybe try to extend your spoiler down.

 

[AUSSIEVETTEMAN]

Thanks

John,

Thanks for your feedback. I have a feeling you are right with the radiator. It looks like it has done a few rounds, though the radiator shop seems to think it's ok.
I put the new cap on because it was puking on the floor after the good run on the highway. I sort of knew that the system may not have been pressurised to it's operating capacity.

Thanks

Tony

 

[AUSSIEVETTEMAN]

Thanks

Jetech,

That's a good one. I'll check the other airm dam stuff. The actual dams are still there.
I'll check the seals around the radiator.

Thanks

Tony

 

[AUSSIEVETTEMAN]

Hi all!

Just to let you all know, I ordered a new radiator and hoses this week.
The old radiator is 2 inches thick and the new one is 2 5/8 inches thick. It should make the difference in cooling the old girl.

I'll let you know.

Cheers

Tony