Cooling issue

My Big Block does not like traffic on hot days. Runs cool at city or highway speeds. 26 inch 3 row alum rad..6 blade steel fan..shroud(blades half in/half out) stock waterpump 180 degree milodin thermostat. Now it appears to me that it is not getting enough air flow through the rad at idle or the waterpump could be upgraded to a high flow. It's a 67 dodge and there is not enough room for stock fan and electric fan.

so is the answer an electric fan system that can push air at the equivolent of 30 to 40 mph , what would be the cfm, or try the HV waterpump? Thanks in advance to all.

Is it possible that your pulleys are wrong? Might be turning the fan too slow.

Stock pulleys

recently switched my 440 over from an electric water pump (w/o a t’stat) to a FlowKooler water pump and 160F t’stat. I noticed about a 20 drop in temperature. It will idle at 185 for over 30 minutes without moving the gauge.

I am running a 26” 3 core as well but I do have dual electric fans. In my opinion, the water pump swap may be the low hanging fruit - cheapest and quickest install vs throwing an electric fan on it. Just my 2 cents.

There are all kinds of “stock” pulleys.

What is the diameter of the bottom one versus the top?

My 1st question would be....how warm does it get? What is being used for a gauge?

Also,
What are the core dimension's H & W?
How big is the fan?
What is the distance between the shroud opening and tips of the fan blade?
When the engine is idling will it hold a shop or paper towel to the front of the radiator?
Will it do so across all areas of the radiator?
I would start with the above

Lastly, putting a fan in front of the radiator is not recommended as it can block the air flow at higher speeds

With electric fans, one normally gets what they pay for and CFM ratings are typically skewed especially on the cheap ones.
There are a number of sources depending on the room available.
Also, the higher CFM fans will draw more current so the charging system and wiring HAVE to be in good shape and sized appropriately

7 inch top...6.5 bottom

3 row 26 inch rad

blades are half in shroud ..half out.. at idle sucks a paper towel instantly and holds it there

Your pump is under driven then with those dimensions.

Putting a larger lower pulley or smaller upper will increase water flow.
That may be all you need.

I wen tot Bouchillion's website to see how the numbers compared. Not sure they are measure the same way the OP is.

In regards to the pulleys?

3 questions Not answered

What are the core dimension's H & W?
How big is the fan?
What is the distance between the shroud opening and tips of the fan blade?

And a few more:
Does the paper towel suck up to the radiator evenly across the entire core?
Will i t do the same with a shop towel ( heavier)
Is the Shroud sealed to the radiator all the way around?
You might try taking some temp readings at various areas of the core as you may have uneven cooling for a number of reasons.

Yes, they sell various pulleys so i went there to see if their dimensions matched the OP's, not that I could tell.

What about timing?

Is the engine over bored a lot?


One thing I learned after years of dealing with this stuff and reading on here, shrouds and fans aren’t that big of a deal. If you get some important stuff correct that is. You need a good condition radiator and you need a good pump. Pulleys are worth looking into, I don’t have a magic bullet set of numbers to post. Just do some research and ensure you have something that will work.

I had a 69 rr that by happen chance came with a broken shroud somebody had duct taped. That just fell on apart one day and I planned to replace it soon. Then I noticed it didn’t make a difference, so that car never got a shroud. People used to freak out about it because the gospel is you must have one. I even started running a 195 factory stat because I didn’t care for the oil turning black so quickly, that made no difference on an auto meter mechanical gauge as far as getting hot. Sat right in the stat all the time. Idle, beating on it.

Also learned on that car that you don’t have to cut the 22” core support when running a 26. Guys freak out about that.

One day I was showing the car to a family member and he said the fan was on backwards. It came that way and I never noticed or need to check as the car never ran hot. I flipped it around and it made no difference. Not even a little.

The recipe?

Stock factory built 383 hp that I poured the sand out of on the stand when I did a little going over and a new chain.
Stock 26” radiator in a 22 hole
Edelbrock pump
Some random aluminum housing. No idea on who made it.
March serpentine belt pulley set that didn’t serpentine, just ran the belt in stock pattern
Stock fan and fan clutch that was good
Good sharp tune up
Jet hot coated headers
Ran right on a 180 and a 195 stat on mechanical gauge even on 90+ humid days

stock bore..molnar stroker crank....timing is fine

Lot of unknowns. You can flush the motor and radiator, see if that helps improve cooling. The Chapter 7 of SM has the cooling specs on pulley ratio, water pump impeller, fan blades. Lot of different stock components.

motor and rad is fairly new and the issue has been from the beginning.( it doesn't streak to a higher temp in traffic..it takes a while to get to 200 . I have tried most everything except going to a HV pump vs stock and upgrading to a 4 row aluminum. I'm not enthused about electric fans but as stated in My original post the car runs cool down the road even on the hottest days so at idle it is not getting enough air through the rad or the circulation may be too slow. With the setup as is...IF the fan could pull air through the rad at the equivolent of 35 mph...it would never go over 180. Down the highway on 90 plus days the car runs at about 175-180.

Do you have an auto trans routed through an internal cooler, do you have a a supplemental cooler in series and where is it located.
I'd try a new thermostat that is tested fir
The pulley situation should be sorted out first.
Flow is important, yet flow can be too fast to effectively cool the water properly.
Is the shroud from the 22" or 24"?
Check the auto trans pan temp for trans temp, and or make sure sender is on correct bung or line (hot area not return) to verify that.

Is the fan direct drive or are you using a fan clutch? Maybe some pics of your setup could help.

So....how hot does it get?? Nothing wrong with 200F

24 inch shroud..6 blade steel fan. Internal trans cooler in alum rad.

at 200 I'm not comfortable. I discussed this earlier with others who claim 220-230 is fine for their old motors. I ran a new analog gauge with the stock gauge on My BB and 180 was center of the dashboard gauge. 200 was just out of the comfort zone..210 pegged it. My experience and driving old iron for 56 years is old motors don't like high heat. They last and run longer/better at 180 to190. Oil doesn"t last well running high temps

I have spent many years chasing cooling issues in customers vehicles and have resolved EVERY ONE OF THEM. It can be a time consuming process. I also spent over 20 years in various engineering positions some of which involved temperature control.
I have posted questions twice and only received a partial answer to one. In reading the above as well as you other posts two things JUMPED out at me.
1. 200 degrees is nothing to be concerned about. 210 also OK if it stays there.
2. You are relying on an auto meter gauge which I have seen be out of whack by as much as 40 degrees as well as other brands. They always go seem to go further out of calibration the warmer they get. While yours is probably OK the only way to be sure is with a thermocouple and digital meter.

Is this a mechanical or electrical gauge? If electric available V (typically lower at idle) and grounds can come into play and impact the readings, especially the sending unit ground.
You haven't stated what the ambient temperatures are or the conditions when this occurs. IE:
1. heavy stop and go,
2. just off the hiway,
3. and how long it takes under various conditions to reach 200 or 210.

While I'll agree your problem (which may not actually be) seems to be related to a lack of air flow it can also be a number of other variables stacking up. IE:
1. The fan pitch is not enough to pull the air for your 3 row radiator.
2. All radiator cores are not created equal. The size of the tubes, their wall thickness, staggered or in line, the number of fins per inch, the thickness of the fins. whether the are louvered or not and how they are attached to the tubes.
3. A clutch fan as suggested by another may tip things towards the cooler side as they are designed to move a lot of air when needed. (think a cop car idling for hours in Az back in the day or a forklift running around in 100+ degrees heat ) Do get a thermally activated clutch if you go that way.
4. Coolant? Anti freeze/water ratio

Answering/verifying questions previously asked should be step #1

Implement simple things like making sure the shroud is sealed to the core #2

Verifying your readings via thermocouple should be step #3 The beauty of the T/C is it responds instantly and is accurate to a .1 or so of a degree. You may not choose to do so or need to as you situation is on the ragged edge but definitely removes any doubt or questions.

Gathering and Recording the Data (answers) to all above posting and questions Step #4

Analyze the above answers to resolve the issue.

I will bet putting the car in neutral and raising the RPM to 1500-2k will make that temp start dropping

reving in neutral didn't have an effect. 50/50 mixture on coolent. 210 is in the overheat range and I would never run an old motor(meaning pre 80's, not condition) at 210. Dash gauge would be pegged.

Increasing the RPM obviously should pull more air through the radiator. If is not having any impact there may be a clue there
not trying to be offensive in anyway but rather making an observation.

I ran a lot of pre 80 Mopar motors on dirt tracks. Without a doubt, I can tell you 210 is not a problem, unless the cooling system is not pressurized. Water in an open pot doesn't even boil at 210. With the cooling system under pressure, 225-235 is hot, and those old Mopar motors did OK unless it stayed at that 225-235 for 10 minutes or longer, under pressure.

Next up, factory gauges were a best guess as far as actual temperature is concerned, the "readings" were generally all over the board, I doubt many were even close. Just because you had one that was in the hot range at 210, I've had several that probably were just into in the operating zone at 200. If you are basing your overheating on a factory gauge with an assumed overheating temp of 210 because of one factory gauge, you probably don't even have a problem you think you have.

3rd, if reving your motor did not effect the temp, you either didn't reve it steadily, or properly. You should have brought the rpm up about 500 rpm, and held it there a minute or so to see if the temp started dropping. If it would have failed to drop then, your perusing air or water flow probably isn't your issue anyway, because that extra 500 rpm would do the same thing as more air or water flow.

as a side note..as far as I'm concerned any and all who submit that a temperature of 210 is fine to run an old engine : don't bother. Not to be nasty but I'll never accept that and submitting and reading is a waste of time for author and reader.

Just another side note..IF 210 was fine..then why only a max of 195 thermostat. is available. New engines have different cooling and pressures to run at.

do a search on cooling and tuning issues...
210 is not hot so quit arguing with us
This thread is another broken record

It is apparent that not only are you ignorant of what a thermostat's purpose is, you are also ignorant of the normal operating parameters of a cooling system.

You don't have a problem, other than the one involving your understanding of how a cooling system functions.

So don't waste our time with your misconceptions.

And love it when one asks for help and then later announces he's an authority on the subject

And to OP, I am truly sorry for wasting my time trying to help, please accept my apologies. If you really want to cool things down, try some LN2 in place of that old 50/50 mix.

If revving in neutral didn't help, your fan is probably junk. Not enough pitch or not enough blade width. Try a different mechanical fan with more / bigger blades and see what happens. They are cheap enough in the junkyard. I had that happen where the car would boil over when idling or trying to go through the drive-up window line at a restaurant. Pegged the needle at 260°. It ended up my fan just wasn't moving enough air. I put a bigger fan on it (with a fan clutch) and it completely solved the problem.

lol....You do understand that 195 is the temp at which the stat STARTS to open....right???

yes...I have a firm grasp on the obvious unlike some others...I'll request the moderators close/delete this as it has gone off the target question. Thanks to some for info...thanks for no real value information to others

most t-stats take approximately another 10-15 degrees to fully open.
i used to be concerned about running hotter than say, 180, but not any more. 230 or 240 for extended periods might make me just a little concerned, but if the temperature returns to around 220, no big deal.
a 16lb. cap with an overflow return tank, plus a reasonably sized and clean radiator, [even a 22" will cool more than you think] and the fan[s] of your choice, will cool all but the most finicky rides.
plus, it helps keep the engine internals cleaner, longer.
my opinion and experience only, after playing with these toys for over 55 years.
obviously, your mileage will vary.

WHAT ABOUT A FAN CLUTCH???? It was mentioned more than once and we still don't know if it is direct or with a clutch. Also it is a aftermarket fan? Flex blade, solid what? Not to be rude but if you want suggestions we need to know all the particulars.

I do not believe a clutch fan is going to do anything else a direct fan is doing at low speed or idle. I have a newer miloden thermostat and it opens at about 190 per my gauge and at highway the temp on the gauge reads around 180. 180 stat

A faulty fan clutch can slip too much. If you don't have one, it's a non issue at idle. If you do have one, it's a possibile problem.

Just for perspective, there were many times we ran 454 Chivvvys at 260* ALL DAY LONG in the AZ/NM/TX heat while towing a trailer & load that weighed 25,000 pounds. And the 454 would be back to take more day after day. Just say-IN!

The OP wants to make his car run 180 or less at idle. It's certainly possible to do that with the right combination of parts and tune. Why is everybody trying to convince him to let his engine run hotter? So what if you can. He doesn't want to.

TY

I got my Savoy to stay under 210 most of the time with a 26" radiator, flow cooler HV pump, 440 Source repo pulleys that are 1-1, and a 190 stat. Still no shroud and it runs cool all day yesterday at 89 degrees for a 1 hour cruise. I just replaced 1 thing at a time until it ran cool.
I found that the rust in my block kept filling my radiator with scale. I installed a coolant filter in my upper hose and I have emptied it 4 times already. It is clear so I can also monitor the flow rate of my coolant. The Flow-Kooler pump really moves some coolant at idle . I understand the fear of anything over 200 but it really isn't dangerous,230-230 yeah you can start to worry about that if it doesn't cool down

Gus

Ultimate fix, Gotta work,


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I think everyone is trying to convince him it's OK to run a bit hotter. He's convinced everyone is wrong. He's also convinced that all the suggestions made so far are wrong. I'm convinced there's no solution to his perceived problem. He's attempting to fix a problem that doesn't exist.

I also get a little worried when the temp gauge starts to go over 180. I know it can run hotter, but sitting in traffic during local events and nowhere to turn into if the temp starts to spike is a little concerning to me.

"He's convinced everyone is wrong." This is one problem with people today who have a deficiency in reading comprehension. Where did I reject suggestions except it's fine to run an old motor at 220 plus degree's. New cars with redesigned systems run fine at 220 plus. Old iron was not designed for that. As stated earlier if My Dodge goes over 210 the stock gauge would be pegged..hence it's trying to show the car is far out of it's "safe" operating temp and action is advised...like a "check engine"or " overheat" lite for all the youngsters.

Anyone who cares to run an old engine at 210 plus "all day" is fine with Me as I know what the end results will be. I am trying to run My Dodge at manufacturer recommended specs.

Search moparts....how many more times do we repeat ourselves...................
Some of us run instrumentation instead of guessing so there is real world data. Hi res AF gauges, digital hi res tachometers, IR temp guns etc.
the thermostat controls the "minimum" operating temp.....

At 195- 210 the fuel burns completely and the air fuel ratio is is not bouncing all over because fuel was collecting in the intake due to the engine being too cold.

This has been posted before and now posted again. Actually I must be lucky managing high hp cars that run laps at 195- 210 that never overheated or blew up. Actually we had 2 of those "hot" engines apart for other issues and they were clean and did not have the "cold engine smell" that engines get when run under temp ...must be a mistake

High under the hood engine temps are the real problem not the operating temp of the engine.
The temp gage will show normal but when the hood goes up everything is cooking

What are these two statement's telling you?



You do not have enough air flow threw the radiator! That could be the fan or the fan is not moving enough air standing still or at slow speeds. You need to figure that out or go with an electric fan.

Well...that was the original question..then some great input..then the urinary olympics....I did try again the high idle test when warm...earlier I stated that it didn't drop the temp. This time the temp gauge was at 190 and I put the car in neutral..ran at 1400 for a minute or so and the temp dropped almost 10 degrees...so in My original post I asked about electric fan being able to push air at the equivolent of 30 to 35 mph driving speed..what CFM that would be. 3 pages later there was no reply to that portion, possibly because I wrote I was not excited about elecrtric fans.

One post was good as I know now my upper pully is larger than the lower. The lower is 6.5 and I can"t find so far, a larger crank pulley and the waterpump pulley is 7.0. I have a 6.5 waterpump pully in the garage so that will be changed so the fan will rotate faster at idle.. It will be a 1/1 ratio rather than less than one.If anyone has a larger crank pulley for a 67 BB with power steering..no air I would be interested. 2 groove

Running cooler at high idle in neutral can indicate an air flow issue, but it can also indicate too much heat from the torque converter if your motor is cammed up and idling high.

are you using a coolant recovery system now ?
this is an overflow tank that introduces the expanding coolant into the tank from the bottom, then with the double gasketed radiator cap, when the coolant cools down, it is returned into the radiator.
this will eliminate air in the system, thus allowing it to run cooler.
the factory system always had an air pocket below the radiator cap, and any excess coolant in the system was expelled onto the ground via the overflow hose.
maybe this will help you maintain your targeted temperature, or get closer to it.

[quote=moparx]are you using a coolant recovery system now ?
this is an overflow tank that introduces the expanding coolant into the tank from the bottom, then with the double gasketed radiator cap, when the coolant cools down, it is returned into the radiator.
this will eliminate air in the system, thus allowing it to run cooler.
the factory system always had an air pocket below the radiator cap, and any excess coolant in the system was expelled onto the ground via the overflow hose.
maybe this will help you maintain your targeted temperature, or get closer to it.


mild cam...new converter....recovery tank installed years ago...engine idles at 800 rpm