440 overheating

[1duster]

I have a 71 duster 440. My engine has less than 50 miles on it and it has had an overheating problem. After about 15 minutes the engine heats up to 215-220 and doesnt cool down well unless i run on the freefay at 2000rps for about 10 minutes at which point it cools only to 200.

I have a two core aluminum radiator ( brand new), flex fan which pulls plenty of air is 1 inch from the radiator, an aluminum pump housing and aluminum high volume water pump. Compression is at 9.75-1 and the timing is set at about ten degrees at idle. carborator is set with new rods and jets sugested by edelbrok tech personal.

Anyone have any thoughts on what the problem could be? I just put a shroud on and it didnt help a bit. even withought a shroud i can put a piece of paper in front of the radiator and it will suck it flat.....anyone?

[1972roadrunner]

what is your thermostat rated at? have you tested it? have you ever thought of a bigger radiator?

just some things to chew on, i'm sure your rad. is big enuff, but i preferr a 4core......just me though

good luck!

[1duster]

160 thermastat......the radiator is large and cools verry well...i know it isnt the problem because i replace a 4 core when i saw that the car was overheating.

[Tarrbabe]

I'd try a 180 or 195 thermostat. With the high volume water-pump the water sometimes won't stay in the radiator long enough to cool the liquid. Before I spent a lot of money, I'd try the stat.

[Mopar_Maniac]

1Duster...

A couple of other things to check out if the t-stat won't cure the problem.

Make sure your lower radiator hose is not sucking closed under higher rpm. Sometimes the high volume pumps can suck it flat. Install a new hose if your using an older one. Install a spring inside the hose like some cars have from the factory.

What diameter is the water pump pulley? Sometimes you can run a smaller diameter pulley to speed up the coolant flow.

One last thought...has it actually overheated? Are you sure the gauge you are using is accurate?

Good luck,
Mopar_Maniac

[1duster]

ok i have one here so i'll try that, If that isnt the problem could i there be a problem with the block or somthing internaly wrong with the engine?

[Tarrbabe]

One more thought, the air-condition water pump has fewer blades to slow the flow down to allow more time in the rad. to inclease time to cool.

[1duster]

yes,
I took it to the track last night and on the second run i had no top end...the car would actualy stop accelerating at 3500rpms. There was a spill on the track so after two hours of cleaning my car had cooled to 160 again. After that the car ran great but the next run it was hot again and no topend.

[Maxwedge]

Put a cowl on the radiator..NOTE the closer the cowl is(and the more of the fan it covers as in curcumfrence) the better and more effiient the fan will come(as in pulling MORE air through the rad)

[Magnum440]

Do you mean "shroud"? If so, he said he got one and it did not help.

Hope the t-stat thing works. Mine is about same as you and i also have a 160 deg.

As far as your loss of power, I'm not sure what that could be. But stuff is getting hot, like fuel line, control box, carb etc., My car does get hot like yours but I dont notice ALOT of loss in power.

[ehostler]

First, get that 160 T-stat out of there and put in a Hi-flow 180. The radiator is questionable. Second, 440s normally like 4 core radiaters, as yours is aluminum, it may be alright. Third, definately run a fan shroud and make sure that the fan is about the half way point of the opening in the shroud and that the shroud is no further than 1" from the blades.

[kenkarner]

have you just overhauled it? There are water passages in the block and the head that are covered up by some of the universal gasgets being made now and by drilling holes in the head gasgets before installation you can greatly improve the cooling of the 440. did this on my 440 with a al. rad. and 100 degrees outside it still runs at 190, in town or on the highway

[1duster]

by the way, our 2 core radiator is larger and holds more water than our previous 4 core did. also the lower hose is new.

[FGilman]

We have a 360 that puts out about 400 horse power. When we first got it running,it to ran hot. Three things I found out , 1. It was sucking air around the intake. You can find this out by taking a can of carb cleaner and spry it around the base of your in take, if the RPM's go up you have a leak. It could be leaking at the base of the carb it self. 2. If the timing is to far advanced it may heat up. or 3. blockage in the cooling. One more thing hopefuly when the heads were put back on the right head gaskets were used the wrong one's could do one of two things, block the water or alow to much water. If the water is moveing to fast it won't cool. good luck

[451Mopar]

Check to see if the radiator cap is holding pressure.
Use a dial-back timming light to check total ignition timming without the vacuum advance, and then again with the vacuum advance as you may have too much ignition advance.
Check the air/fuel mixture. Sometimes spark plug readings don't help with the unleaded gas, you may need to install 02 sensor(s) or spend a few bucks and take the car to a chassis dyno that has a wide-band air/fuel meter.
I took my car to a chassis dyno durring a car clubs dyno day and it was only $50. The results are nice to have to see if the carb is tuned correctly. The down side of the $50 dyno day is they did not allow any changes (too many people to use the dyno that day, and they charge extra for tuning changes.)
My cars air/fuel was pretty good, but that was from making many changes at the drag strip.
Others had really screwed up carb jettings, that were nowhere near what they should be.

[Maxwedge]

does the shroud go all the way around the fan and how close is it to the blades? thats what is important. If he has alot of crud in the block tho it wont matter how much fan/pump/rad he has its still going to overheat.

[Doug Wilson]

Man... you sure are getting buried in really good advice. Here's what I'd do, stealing it from the other guys':

First - check the 'stat, maybe replace it anyway with a high flow 180 or 190.

Second: check the guage - put a candy thermometer in your open radiator cap hole, warm the engine up and compare guage readings.

Third: Fan shroud.

Fourth: maybe this should be first - new engines often run hot for the first XXX miles. Find out your clearances from your engine builder and ask him about the heat.

Fifth: Timing curve.

Sixth: Air/Fuel ratio.


All the above are related to your perception that the engine is overheating. As far as the performance goes, I think you need to exactly describe what is happening - sounds, etc. - before I can offer much in the way of opinion.

[Tarrbabe]

Because 4 core rad. HAS 4 cores, it has a greater surface area. Greater surface area means more cooling power. Greater water capacity and less surface area means you will have more water hotter and less cooling area with the two core.
Just thinking out loud again.

[Magnum440]

IMHO. The point is, he has the very common problem of over heating at idle and low speed/RPM driving. This USUALLY is fixed with a good shroud. I think if ther was a blockage in the block/heads it would never cool down. Over 50 mph, a fan is'nt even needed.So something in the COOLING system must not be working right, IMHO.

[Doug Wilson]

Right on, Mag.

[Magnum440]

Just trying to find some answers myself--dont want to steal the thread,tho.

Part of my problem is underdrive(March)pulleys, a humongous trans cooler in front of the rad and no shroud. I just bought a Spal hi torque fan. The tech at BeCool says it'll do the trick--we'll see!

[dkn1997]

my 440 was an overheating nightmare last summer. I will share some of what I learned.

-I was running my stock 318 radiator, but I had it recored (4 core high efficiency)

-underdrive pulleys
-flowkooler hv water pump
-redline waterwetter
-MP thermostatic clutch fan kit
-shroud
-160 t stat
-aux tranny cooler

changed to aluminum be cool direct fit radiator,no help



changed back to stock pulleys, no help.

changed fan clutch, no help

tried aux small electric pusher fan, no help

yanked the whole mechanical fan setup, replaced with 2100cfm electric, no help

ran tranny lines to just tranny cooler, bypassed radiator, no help.

Was ready to try an even more expensive electric fan, but local speed shop told me to just try a flex fan w/ my shroud.

Installed flex fan (no clutch) &shroud, and my 2100 cfm electric in front of radiator and problem solved. never gets above 180, even on 95+ degree days sitting in traffic.

I do not know if anyone mentioned this to you, but what type of aluminum radiator do you have? Before I got the direct fit rad, I ordered the universal fit one supposedly for a street car, and this thing looked like it could not cool a lawnmower, so puny compared to the direct fit model.

I suspect something with rad, before I finally nailed my problem, the car ran cool while driving, I mean like 160 in light cruise (20-30 mph) idling was problem.

I hope this helps, good luck.

[1duster]

dkn,
It sounds like you just covered up a problem instead of solving it. I want to avoid that by all means possible. You are sucking so much air thru that radiator it could cool an apartment building . The aluminum radiator i have is fine, it looks just like a be-cool.


I tried the 180 t stat today and it seemed to help a little, i could drive on the highway and it would bounce above and below 180 but then if i stop once it wont go back below 200. I have pretty much looked at all the cooling components and am now going to inspect a possibly lean carb. IM going to bring it to a shop and have the exhaust probed. THe carb is the last thing i can think of before resorting to the flexfan and electric fan combo that dkn uses. ONe more thought..... today the temperature here was.........rrr........115 so maybe i didnt give the tstat a fair chance .

[gsmopar]

1Duster,

You have to get a good grip on this issue. When you mentioned the temperature, I checked to see where you're from. I'm a AZ resident too and plan on starting up my Charger (first time in 4 years) next month. I would like to learn from your mistakes if at all possible!!! BTW, what are you going to do for emissions?

Later,

Greg

[dkn1997]

The amount of air I am pulling through my radiator may be enough to "cool an apartment building." Funny thing, though. That same amount of air happens to be just the right amount to cool the engine properly

And I do not call correcting an overheating problem a "cover up" bottom line is, the thing was an overheating steaming turd before, and now runs cool as a cucumber. Also saves me the embarassment of having to put a bucket under it at the local cruise night, or the quick walk away after I park it and can hear the thing puking it's guts up all over the place. That totally sucked!!

Anyway, good luck with your problem and I hope you find the answer you are looking for.

Kevin

[Maxwedge]

I would tend to think that if going a steady speed fixes the over heating problem then its about airflow and rad size. Did you have to block tanked and stripped of all the crud inside?

[rmrod]

Your in good company and not alone. Suggest you backtrack to the time that the engine was built. Sounds like a freeze plug or two are inside the water passages. These engines never ran that hot when Ma Mopar built them 30 + years ago without all the fancy pumps, radiators, etc.

[Magnum440]

dkn1997--I appreciate you sharing your"nightmare.' And glad you finally found something that worked! I will be about halfway down your list soon. With the 2800 cfm puller fan and if that dont work I may try your set up.

Horsepower=Heat. A modified 440 today is making 100 to 200 more Hp than what Ma originally intended. All makes suffer the same. Thats why the after market has provided Hi-Flow/Volumn pumps, flex fans, aluminum rads and electric fan systems. Driving these type of cars on the street presents problems that even the pros have trouble solving. Innovation and experimenting is the only way.

[dkn1997]

hey magnum, hope you solve that. In regards to my current setup, I got the idea from a friend who is a tech at a local truck dealership. When all this was going on, he pointed out that new trucks w/ heavy duty cooling often use a mechanical puller backed up by an electric for towing heavy loads and such.

The key was ditching the clutch fan. I tried two of them, but who knows, maybe I got two bad ones? seems unlikely. And I do not think the flex fan costs me too much hp. plus, I painted it black for the stealth look!!!

[1duster]

rmrod,
I agree completly and thats why i am ancious to find out what is causing the problem. MY dad had a'70 440+6 roadrunner that never heated up above 180 and that was here in phoenix ( and thats not a stock engine, dynoed at 530 hp). One question....did these cars come equiped with shrouds? MAybe i could find a better one at a junk yard..........but my problem is that because my car was origionaly a /6 car, the engine sits more to the passenger side so the fan isnt centere on the radiatr making it hard to find a good shroud for my rad.