My '70 R/T is having some cooling issues. When I'm rolling I'm OK. When I start hitting a string of lights and stop signs it'll shoot up anywhere from 210 to 250 depending on how long I sit.

I'm running a Be Cool Dual core aluminum radiator, 2 10" Zirgo fans, 1149 cfm each, diagonal inlet to outlet, turning on at 185 degrees.. Mr. Gasket HP 180 degree thermostat, must have a high flow water pump. The flow is crazy.

Other than that the car is your standard street rod with headers, mild cam, msd box, trans cooler, blah blah blah....

When I take off it takes a while to return to a reasonable temp, and thats only if I can keep going at a good clip. Is it possible the coolant is flowing too much? If I shut the car off for 5 minutes and let the fans run, It cools right down when I start it up. Seems like it take forever to warm up to 180 at an idle, but after the thermostat opens, the temp just goes up and up.

Anyone?  

What psi rating is your radiator cap? What coolant/water ratio?
Do you loose any coolant? And yes, it's possible there is to much pressure [not enough time for heat transfer] and cavitation can sometimes come in to play...
but, does the fan shroud cover the entire radiator? and have you pressure tested the cooling system first?  

Thanks for the reply!

I bought this car last November, from a guy who supposedly took it to the strip a lot, so I'm not sure what's what, but it looks like it has the 13psi cap. Coolant is very green, I'm assuming there is way more coolant than water. What should the ratio be?

Have not pressure tested cooling system, and there is no shroud, just the 2 fans zip tied to the radiator. Fans are pullers. Seems to be pulling a ton of air, and you can feel good suction from the front of the radiator.

I've been thinking about going to a clutch fan and shroud. If I do that, what fan will work and not break the bank? Original style, or flex fan?  

Hopefully the guy didn't use block filler cause that will make it run hot when daily driving.
I hate electric fans [except fir the fact there's less parasitic drag] other than that fk'm.  
13lbs is too weak! 16lb cap is the way!!!!!!!
Though your elec fans pull 1149cfm I wonder that it would make almost no difference to have them off @ cruising?
If the fan cover most off the radiator & is 1 inch from radiator you probably don't need a fan shroud, but if stop&go is your bsg then the shroud will help to concentrate the lower air speed from the fan at low rpm-idle ect.
I like a quality flex fan like flex o lite they are well balanced and don't weigh a ton and won't flatten out like other have been known to do.
17'-19' I use the 19'. Just changing to the 19' from 17'= lowered temp 8* keeps her cool through the drive thru and such.  

The car never really gets above 170 when cruising at 45+mph.....slower speeds it sits at 190, if the temp is not too hot outside, it takes about 10 minutes to creep up to 210 at an idle, that's after it's already warm, but continues to slowly rise. You're probably right about the flex fan to help pull air at a stop. I have the electric fans set to come on at around 185.

What temp should it sit at after idling for a long time?  

Your electric fans are to small. How do we know simple when you drive the vehicle at 45 mph the rad is being cooled by the air passing through the grill and you have already told us you have no problem at speed. Don't ever let your engine get to 250 degrees, pull over and cool it off until you sort this problem out. I can tell you 2 10" electric fans for a big block, not even close, how about 2 16", or better yet get rid of the electric fans, they are ment for racing a 1/4 mile. Short bursts down the quarter mile, and to cool the engine in the pits.
Install a factory clutch fan with a new mopar performance clutch unit, with a 18 or 19" 6 or 7 blade fan from summit.
Mix the anti-freeze/water 50/50 and if your engine has seen 250 reg. I would replace the thermostat with a high flow 160 or 180 summit piece.
I have this set up on my car and when the clutch ingauges at about 190 degrees the engine drops 20 degrees in any traffic. I also run a mopar 16 inch fan in front of the rad which pushs for when I am at the track.  

A friend came over we started talking about 440 running hot i told him my 426 never got hot but that 440.  He said head gaskets rong water passage holes punch out same size as block and head. I talked to other people they say thats true  

Thanks for all the advise! I'm going to start with a clutch fan, we'll see what happens from there. What shroud can I use? I noticed that the mopar shroud at summit is only a 16" diameter, and is this the right fan? FLX-5718


No, it doesn't see 250 on a regular basis. It happened once while waiting to get out of a gas station. I've been REALLY careful ever since.

Alright, one more problem........
I changed the spark plugs and took it on a 20 mile ride. Most of the old plugs were carbon fouled, so I turned the screw  on the carb in a bit. Now the plug insulators are a light tan (That's good right?). The problem is that there is oil on some of the plugs. The car does use a little oil, and I'm getting a bit of white smoke out of the exhaust. Rings? Valves? All of the above?

I don't mean to sound like an idiot here, but I've only had the car a 9 months and I'm beginning to really get to know it. 5 of the 9 months were winter, so I didn't drive it much. I've never had to tear into a car's engine before, just the usual upkeep. I was looking for a Coronet 500 that was all stock, but wound up with this R/T with the your guess is as good as mine 440. Beautiful car, just has some engine issues I guess. Nothing that time and money can't fix!  

Plug readings, your tan reading is good with todays unleaded fuel, that is what you would expect from a properly set up engine.
Oil on the plugs, not so good, suggests a tired engine in need of repair or a rebuild. To determine what is causing the problem, a compression test will need to be done.
Make a note of which cyls. have oil on the plugs.
All cyl. should measure within 10% of each other.
After the test squirt some oil in the cyls. and redo the test. If you find a cyl. were the comp. did not improve as much as the others than likely you have found a problem cyl.
It could be a broken or worn ring, or possibly worn valve guides. If this engine was drag raced it might be a good idea to tear it down over the winter to determine its condition.
If the problem is border line, I would recommend using 20w50 with a quart of Lucas oil stabilizer, this stuff really does work and can help a worn engine run for yrs.  

Sounds like a plan. Right now it's full of 10w30 full synthetic. Several people have told me that the engine would be better off with traditional oil and I should ween it off the synthetic, but I agree, it's going to have to be taken apart. The thought doesn't thrill me, but it's better than destroying a sweet 440.  

The problem you are going to face with reg. oil is that most of the good stuff like zinc has been removed as of late. Zinc was needed to help protect the flat tappet cam your 440 has. If you are going to use reg. oil use something with a Sl, or Sj rating. Motor oils with this rating have what it takes to protect your  camshaft.
A good alternative to use is Mobil 1 Synthetic 15w50, although this oil is rated as an SM, their web site claims they have additives to protect flat tappet cams. I have used this product and am happy with it with it in my solid lift motor, which is a street/strip car.
I used to mix it 50/50 with reg. 20w50 but lately I  have been unable to find a good reg. oil. Now I just run the 15w50 Mobil. I would try this oil before tearing the engine down and see if you have any improvement. 10w30 Synthetic is like water when its hot, the heavier oil may get you through the summer, its worth a try, besides this is exactly why oil companies make heavier oils, for engines with oil problems, especially x racing engines.  

Hi,

I had a similar problem.  I have a great big pair of fans and a great big Be Cool radiator.  It never seemed to be enough for 90 degree days or hotter.  For me the most useful changes were to

1: Enrich the idle mixture a little more than "ideal".  After some time with my car I added an oxygen sensor.  One useful bit of data it gave me was that as the engine heated up the idle mixture became pretty lean.  The idle was became a little crappy and the engine got even hotter when this happened.
2: Use stock pulleys.  If you have underdrive pulleys then you probably already know that they will slow down the drive of your water pump.  It's not a big deal until you want to idle for a while.  I had underdrive pulleys on a street car for a while - bad mix.  I never got enough juice from my alternator and I'm pretty sure this also affected my cooling system.  Don't forget that your belt-drive fan will also be affected by an underdrive pulley set.
3: Check your coolant mix.  Pure coolant is less heat-conductive than a proper coolant mixture.  Fixing this won't make "all the difference" but every little bit will help.  There are also additives you can use to improve this - slightly.

I tend to agree with the fan advice the other folks have given.  A parting thought . . . the stock radiator/fan combo for a 440 car looks less impressive than the average Be Cool raidiator set-up, yet when the engine is running properly the original radiators tended to be big enough to do the job.  

I have electric fans.  They come on at 185.  The whole thing usually works reliably all the way up to about 95 degrees.  Above that the fans don't cycle off until the car is rolling.  

Thanks for all the great advise. I'll try some of it out. My cooling mix is 50/50 on the nose, so I've got that going for me. Maybe I should pull the small trans cooler off the radiator?  I think I'm going to go with a shroud and clutch fan. Just need a bit more info......
Does anyone know if the 26" Chrysler restoration shroud will work?  I see it's 26" wide, but what size is the opening? If I get a, 18" fan, will it work? I haven't seen the stock set up to know, but does the fan need to be inside the opening of the shroud, or just outside of it? Has anyone used the flexalite  6 blade aftermarket fan and clutch? I have a friend using what looks like a universal shroud and a regular bolt on fan with no clutch, but also has an electric fan set to come on at 200 degrees. Seems to work out, but I'd like to go witha clutch fan if possible.  

I have run with and without a shroud on a big block, in traffic it is only worth maybe 5 degrees, for me this was not worth the effort.
I would rather run a 18" fan than say a factory 16 or
17 with a shroud. Although the shroud is nice if your sticking your head over the front of the rad with a tie on, Ha Ha.
If you do run a shroud it is best to get a fan that will fit inside although this to is not necessary and can lead to other problems, e.g. watch for a tight fit,  engine torque can cause the engine to lift slightly to the right when accelerating causing the fan to crack or break the shroud.  

I'll try an 18" without a shroud first. There's not a lot of room between the pulley  and the radiator right now as it is. Maybe 4". I'd never fit an 18" fan in front of a shroud. At least I don't think so. Going to a cruise night this Friday. I'll check out some different setups on some other BB Mopars.