Re: Running a little hot, but only when a/c is on
 

All excellent points. I have found that, at coolant change I add a bottle of Water Wetter (A Red Line Oil product; similar products available from others) and it also helps to lower temperatures a little more than just the coolant change alone. My understanding is that these type of products help to break the water's surface tension so that the water is better able to get closer to the heated metal and thus absorb and transfer heat better (at least that is what I think). I would be interested in hearing from anyone using a product like this, in these more extreme climates. Dois it help you?

Re: Running a little hot, but only when a/c is on
 

Paul Ive never used it before IMHO its a snake oil product. I used to work in autoparts when I was in college. Its in the same line as the Desert Protection Package the dealership used to sell as a sealant for the paint out here in AZ so many years ago. Basically Mop n Glo

Re: Running a little hot, but only when a/c is on
 

This has been heavily debated on the old list server many times. I can tell you this, it's a much more complex subject than you'd think.
Terms like "nucleate boiling" and "non-aqueous" coolants that keep pressures down up to 350deg but which are designed for the short use life span of race engines.

Here is a review of "water wetter":
http://www.thetruthaboutcars.com/200...%C2%AE-review/
Keep in mind it's just one view.


In my experience of reading and looking at the various results folks get from different solutions the improved Ron Davis (and similar) radiators are the way to go. I still have the stock one but when the time comes..... no question but that I'll swap for the bigger unit.

Re: Running a little hot, but only when a/c is on
 

UPDATED:

pulled the shroud off and had a look before ordering a new radiator. There was a fair amount of dirt and grit stuck to some left over oily sheen probably from the oil cooler repair 18 months ago. looks to cover 25-30% of the entire radiator, and, naturally, over the useful part that flows through the passenger side fan duct area.

http://i29.photobucket.com/albums/c2...il_grit_sm.jpg

http://i29.photobucket.com/albums/c2.../rad_dirt2.jpg

I tried to clean as much of the oil up last time when the whole oil cooler and radiator where removed, but it had been leaking with the previous owner for so long, that oil was coming out of all kinds of nooks for weeks after. Anyhow, gonna try to go with the cleaning rather than drain the water and take everything apart. the oil cooler and condensor looked ok, except they are going to get a once over on fin combing due to minor pebble and bug damage.

Re: Running a little hot, but only when a/c is on
 

I know the newer vettes control speed, but I was inferring that there is a possibility that one of the fans was going out with bearing friction and was not spinning- I don't think that is the case with my car since they spin easy on the bearings still.

also the condensor was 99% clear of debris from a casual inspection through the inlet. It was pretty dirt after all.

Re: Running a little hot, but only when a/c is on
 

Here is a fairly easy way to keep from having to clean the radiator stack:
http://www.zr1netregistry.com/ZR1_radiatorscreen.htm

I clean this screen out 3 - 4 times a year.
It fills quickly with junk that would otherwise go up into the stack.

Re: Running a little hot, but only when a/c is on
 

There was minimal debris, although a little bit none-the-less- mostly appeared to be dirt build up with an oily base to stick to. Nevertheless, I somewhat feel like a noob for posting before looking- everybody nose that C4's suck up more stuff up the schnoze than a coke addict.

Re: Running a little hot, but only when a/c is on
 

If you do install a screen you want one that stops the small debis too.
I used a two layer approach. The 1/2in mesh give structural support and the smaller mesh screen stops even those very small pebbles that get lodged in the radiator fins. (or worse pop a hole in the radiator)
Also you'll note it is mounted behind the wing (see link) and support bars so to be less noticeable. There are no alterations to the car when mounting. No holes to drill and is not visible when looking at the car from the front.

I did this mesh back in 98 after cleaning the radiator stack. It's been very low maintenance. It takes just a few swipes of a stiff bristle brush and you have a hand full of crap to throw away.
http://www.zr1netregistry.com/ZR1_radiatorscreen.htm

Re: Running a little hot, but only when a/c is on
 

Do you think this (significantly) reduces air flow through the stack? Probably still better than collecting crap.