The coronet runs a little warmer than I feel it needs to. A tad over halfway on the factory gauge . I have not ckd with a temp gun or mechanical gauge yet....... But raise the hood and it definitely seems warmer then the Satellite does in same ambient temps
Ive already replaced thermostat with a high flow style

The car runs ok , But seems to run warmer the more you drive it.
Like sitting at light. it warms up a tad, but doesnt cool down once moving again . Like my Satellite does.
Timing is right , carb seems adjusted right .

I don't feel like it over heats ,,,,,, just would like to cool it down a tad . Especially before I get the air working here soon

Anyone ever used CLR to clean a radiator out?
Im thinking lay it on its back and fill it up, and just let soak for a bit. then flush and reinstall

Thoughts ???

I don't know feeling warmer is a good guide.

I would want temp readings.

and temps creeping up at a light could be a few things. clutch if you are using one, water pump or fan not deep enough in the shroud.

but if you are going to flush, I think this might be a better choice.
https://www.evapo-rust.com/restore-your-engines-cooling-system/
someone recommended it to me and I got a couple qts to try, just got it today, but won't have time to try it for a week or two.

No fan clutch as its direct drive. Fan blades are dead center in the shroud edge.

I was thinking pick up a decent mechanical gauge before doing anything to have a better baseline on actual temps

I tend to think if it was water pump it would cool down once moving again, at least a little bit.
My Satellite runs right at 180ish range with a Stewart components Tstat. Even on a 100 plus degree day even in traffic. It may warm up close to 200 at stops but cools right back down once moving. And the coronet feels warmer underhood than the Satellite does

When I first got the Satellite it would run warmer the more you drove it . And I did basically same thing. Flushed the radiator and block ( with garden hose and radiator in car ) Went with the stewart Components Tstat and it cured it

ps, the Satellite has an aftermkt mechanical gauge in it .

I've used Radiator Flush. I believe Prestone brand.

The usual questions apply:
What is the real coolant temp ? (mech gauge)
Hoses collapsing ? (observe running/hot)
Blockage in engine or radiator ? (water in = water out, test separately; for engine,with T-stat out)

Never thought of using CLR for a flush but in the past I've used the Prestone stuff.
Best is if you have a radiator shop clean it out (assuming there's one in your area).
Haven't had that issue for decades, since switching to distilled water w/Water Wetter and coolant.
But who knows what the prior owner did.

I’ve never used clr.

I’ve had a few engines that kept pushing casting sand into the radiator. No matter what I used or how many flushes, it would just build up and need to be taken to a radiator shop. High speed blasts would break the crud loose soon after. Especially sustained interstate flat out runs…

My thought is: With so many radiator flush products on the market, what made you jump directly to CLR? Not trying to be critical, just curious...
Personally, I'd be afraid of the potential affects of un-tested chemicals (in CLR) on the gaskets/sealants they're going to come in contact with.

Simple answer ....Was walking thru dept store and spotted the bottle. Thought.....will it clean a radiator internally.?????
.

Radiator will not be in the car . Im planning pull it and lay it on its back . Filling radiator only. Then flush several times becore reinstall in car.

I will head out tomorrow and pick up a mech gauge . Before doing anything but deep down have feeling its warm....at least warmer than i want ot to run

Oh...you said that but I assumed (I know) you meant a complete motor flush. On a bare radiator I don't think it could hurt.

What I may do is drain refill and add flush/ cleaner . flush again,

then pull radiator and fill it will cleaner only and let it sit a while.
the flush it seperately.
resinstall and go for a drive

Right now, car has 1 gallon coolant, then filled with tap water. new 160 Stewart Components stat . No water wetter of any kind
And if I were a betting man would say its over 200 degrees. ( I will know tomorrow afternoon ) And I know some say thats not hot
But its to hot for my tastes

Oxalic acid has been considered a good flush for more than 50 years.

https://www.astm.org/stp25166s.html

The evaporust special gell certainly looks interesting,
maybe after a first oxalic acid cleaning?

A video boroscope “snake camera” to view interior passages after a flush seems logical,
since their price has come down so much,
and they have so many uses.
The smaller than 9 mm camera diameter is very handy.

Bill, I would check the radiator with an infrared heat gun all over the radiator and make sure it is even everywhere. My '68 RR would be fine and if you opened the cap and looked in you would think the radiator was perfect. Go for a stop and go drive and it would lose coolant after it heat soaked when you stopped. Took out the infrared heat gun and the whole right/passenger's side upper corner had no or lower temp and was completely clogged. Re-cored it and no problems. Make sure with a infrared heat gun the radiator doesn't have bad areas and the temp is even. (didn't read all of the posts so if this has been suggested, oops )

Make sure your mechanical gauge is accurate before trusting it
I've seen and had some expensive ones that weren't
The first one was a race large diameter320 degree reading face Autometer mechanical temp gauge with the sender plumbed into the water pump housing next to the upper radiator hose thermostat housing, it would read 140 F when the water flowing into the radiator was less than my body temps were
The last street car I built had a Griffen copper and brass cross flow 4 core radiator that was a little shorter in height than the opening in the radiator support so some of the air would flow under it instead of all the air flowing through it It would get hot, above 220F, driving in town and not cool down when driving it at or above 50 MPH on the highways
I replaced it with a two core aluminum and it ran 165F in town and would cool down to 160F when slowing down on the highways on the off ramps
The next summer it was back to running hotter so I had the radiator back flush at our local radiator shop and that fixed it for that year
That motor was my first pump gas 400 stroker motor that ran on 91 octane pump gas here in Oregon. that motor made 612 HP at 5500 RPM before installed in the car, I used a low deck six pack intake with a set of 1970 440 automatic non CA carbs, that car, 1971 duster weighing 3450 Lbs. with me in it, exceeded my wildest expectations by running 10:69 at 124.+ MPH on Oregon pump gas with the air cleaner and full 3.0 inch exhaust system on the car with the Magna Flow 14x7 oval muffs, mounted behind the rear end the first time out
if it runs between 180 and 220 F I wouldn't worry about that, if it runs hotter or cooler fix it

Once you have the radiator all flushed out I would get a radiator shroud if you don't have one and a thermostatic clutch fan. Both those will improve on the cooling.

It has a shroud.
And i picked up a mechanical gauge today.
Already verified its accuracy on the stovetop with thermostat before installing in car

Your engs.may have different water pump blade counts 6 vs 8 just a thought.

i have used CLR to unclog heater cores in the car,pumped it back and forth with a drill powered pump,worked great,no problem

Update

Ive got the mech gauge on it .

Going in this morning temps ran right on the 160 thermostat. Ambient temps were in the 60s

Coming home in town driving it got to about 180ish, ambient temps were mid 90s
Once on the interstate temps crept up to the mid 190s range.
once off the hiway it cooled back down slightly to about 185ish

This is with a Stewart Components 160 hi flow stat , 1 gallon prestone antifreeze and the rest filled with tap water . It has a fixed blade aftermkt aluminum fan and stock pulleys

I can see the fan itself causing temps to rise in town stop and go driving ,,,,,, but should make no difference on the interstate speeds . I dont know what blades the water pump has on it


I have not just let it sit and extended idle to see where it goes yet



My Satellite with this very thermostat runs right on the 160ish range as long as its moving. Temps will creep up on it slightly but as soon as its moving again it cools right back down pretty quick .
This Coronet doesnt seem to cool back down like the Satellite does once moving. thus why Im thinking radiator flow

Bill an infrared heat gun will tell you something about how your flow is through the radiator. It should be "approximately" the same all over if it is flowing properly and somewhat cooler at or near the return/bottom, just saying.

Mike,

Im going to pull the ac condenser to ck the radiator like you mentioned. With the AC stuff in there . Im afraid theres not much room to get very accurate temp readings