Fan Shroud Fail

[Brass]

Over the weekend I ran into some very heavy traffic, inching along for about 20 minutes.  Unfortunately the new fan shroud doesn't seem to be helping all that much.  The temperature kept creeping to about 230 before I got back onto the open road.  I'm sure it would've kept getting hotter had the traffic not eased up.  

The car has a 440 with a 3 row, 22" radiator & shroud, stock water pump & fan, 180 degree high-flow thermostat, and a transmission cooler.  No leaks, new(ish) hoses, and the radiator checks out.  Timing and tuning are fine.

It runs at a very consistent, very steady 170-175 while cruising so I think it's an airflow problem.  Yet the fan pulls hard enough through the radiator to trap paper, and it'll idle in park for over an hour without overheating.  So is the load on the engine the problem?  Could idling at ~750-800 rpm in gear instead of 950 rpm generate more heat, slow the fan down, or decrease water-flow enough to make a difference?

At this point I'm wondering if there are any options, short of a radiator swap, to help this thing cool better in bumper-to-bumper conditions.  I may start using Evans NPG+ coolant to help guard against boil-over but that stuff is really expensive.  

Thoughts and suggestions are welcome.  Thanks.

[FLG]

Did you happen to change the WP housing to a 440 source unit? (theres a sticky thread with issues with this housing)

Regardless of cooling id bump up the idle a bit, helps with cam oiling as there splash lubed so at idle there minimal oil flow up there and a bit more helps keep lobes happy. I assume your using a clutch fan? Is it slipping at all?

[Brass]

Using the stock water pump housing - no clutch fan.  I've heard clutch fans can save some HP and work fine at speed - but may not be as reliable under these conditions.  So I haven't made that change yet.

Maybe I should also mention that according to the thermal gun, the temp gauge is accurate.

[tan top]

what water pump you running & what pulley ??

[matrout76]

I'm pretty new to the Mopar 440's.  the only thing i've ever driven with a 440 was my grandpa's 1978 Coachmen motorhome...

But, i've been around a lot of other engines, and dealt with a lot of overheating problems with warmed up AMC v-8's.  I figured out the problems with those, and they may have similar problems to the 440's.

general question:  do the 440's have a coolant bypass system?  if so, how is it plumbed from the factory?  

what intake manifold are you running?

the coolant bypass system on the AMC v-8's is intended to help warm up the engine by bypassing the thermostat and radiator.  essentially, the water pump circulates coolant thru the engine to prevent air-lock and hot and cold spots.  with a factory engine, there are never any problems...

the problem on the AMC v-8's turns out to be the Edelbrock intake manifold is so "open" that it allows too much coolant to bypass the radiator at idle. the route thru the intake manifold ends up being the path of least resistance, so the WP just circulates hot water at idle.  at higher rpm (off idle) the water pump moves enough coolant for the radiator to cool the engine.  I've come up with a few easy fixes for the AMC v-8, so some of those may apply to the 440's.

Matt

[FLG]

No bypass system, 440 intakes don't see any water 

I think most, if not all big block mopar engines don't have any water that go to the intake.

[A383Wing]

no water runs through the intake manifold on a Chrysler big block....they are dry intakes

by pass is in the water pump housing

I'm thinking an airflow problem as well....I'm running a non-thermal fan clutch on all my cars....it's engaged at lower RPM's and dis-engaged at higher RPM's

or possibly part plugged radiator

[Brass]

what water pump you running & what pulley ??

Stock pump and pulley...

[tan top]

just thinking  because  , if  you have a non a/c pulley on a stock A/C pump , or it might be the other way round ! but one of the two !!      can cause it to overheat , or run hot  as pump  turns too fast or slow   i always get these two mixed up ,  think its a none A/C pully with an Ac pump  sorry if this sounds confusing , but went through this years ago  

[68X426]

Time for an electric water pump? Electric fan?

[A383Wing]

it's actually both ways.....you cannot mix pumps & pulleys....one way it will cause cavatation, and the other way water will not run fast enough

[resq302]

Well, since I battled this issue a couple years ago, I really read through the factory service manual and found out that if you got a 440 auto without an axle package, you got the 22" rad WITH a shroud.  Now if you got a 383 4 bbl with a 4 spd, you got the same rad but without a shroud.  I can not remember if the 440 cars got a fan with a clutch or not but I know for the 383 4 bbl 4 spd, it was a solid spacer and fan.  The problem I had was that I had an air pocket in the block that would not release and Ron suggested that I raise up the front of the car, such as on ramps, and run with the rad cap off.  Sure enough, huge burp and then had to add more coolant.  I also found that I was running lean at idle which would cause higher temps but cool off once I started moving a bit.  I now have a correct fan shroud and brackets should I do any mods to my engine that require additional air flow to cool it just because the original shrouds are so hard to find and I have not heard good things about the repros unless they changed the material they are made out of.

I, personally, would try the burping thing first, check your timing, and then recheck your idle in gear.  Something as simple as a drop in rpms could be the culprit to making it run just a bit lean in traffic.  Idling in park might be just enough of a bump up in rpms to get enough flow keeping it cool when you are idling.

[tan top]

it's actually both ways.....you cannot mix pumps & pulleys....one way it will cause cavatation, and the other way water will not run fast enough

thanks for sorting out my confusion   

[Brass]

I guess for starters I'll raise the car up and see if I can expel any trapped air.  Seems like a good idea – thanks for the comments!  BTW: the shroud is a 69 reproduction from Layson's Restorations, so I'm not sure how well it's actually performing.  But I'm using the mounting brackets compatible with the 69 and it seems to fit just right.  (Blades are about ~50% enshrouded.)  The engine, transmission, and rear axle are not original.

[elacruze]

Also check the transmission temperature when the engine is getting hot. If the trans is overheating for some reason, the heat is rejected into the radiator and can overheat you while the engine is just fine. Seems unlikely, but if the difference between fine and overheating is being in gear, you should check it.

[Charger-Bodie]

Have you tried Water Wetter by any chance? I have found that the stuff really does work wonders.

[firefighter3931]

An engine under load will generate more heat....that is a given. Your car is experiencing this because it can idle in park and maintain 170* but sitting in traffic (in gear) it heats up.

I would try speeding the idle up to 850-900 and see if that helps. Another option is to just shift to neutral when stopped in traffic (I allways do this)

I bet if you ran a stand alone trans cooler, bypassing the rad it would run cool....just like it does in Park. Fwiw, i've been bypassing the rad trans cooler for years and running stand alone B&M stacked plate units. 



Ron

[resq302]

I guess for starters I'll raise the car up and see if I can expel any trapped air.  Seems like a good idea – thanks for the comments!  BTW: the shroud is a 69 reproduction from Layson's Restorations, so I'm not sure how well it's actually performing.  But I'm using the mounting brackets compatible with the 69 and it seems to fit just right.  (Blades are about ~50% enshrouded.)  The engine, transmission, and rear axle are not original.

Be careful with the repro fan shroud.  Problems I have heard with the early ones was that the thin plastic piece on the top of the shroud that covers the fan blades warp / sag with heat and then come in contact with the fan causing bent blades, even broken pieces that can have catastrophic problems.  That is the whole reason why I got an original one.

Elacruze brought up a good point.  I forgot that if there was a trans temp problem, it would basically dump excess heat into the rad and raise your engine temp.

As Ron said, usually if I am stuck in traffic towing one of our cars with the trailer, I pop the trucks trans into neutral or park to take the load off the engine and to also raise the idle which circulates more coolant.  However, if I am driving the charger and get stuck in traffic on a hot day, I am pretty much screwed unless the traffic breaks up and I can start moving and get the engine speed up circulating the coolant more.

[Cooter]

All these suggestions are great ones to be sure, but after you've exhausted all these things and it STILL RUNS HOT IN TRAFFIC, take this to heart....


Some 440's will run hotter than others I don't care what you try to do to stop it..Either sell the car or live with it..If it's NOT puking coolant out the overflow, it's not running to hot for itself to not like it...I know this sounds horrid, but you'll drive yourself crazy chasing this sh*t like I did..I finally said to myself, F**k it, let the hot headed bi*ch blow....

[Brass]

Hilarious – I think you're right, Cooter!  Thanks for the perspective.

Ron, as FYI, it is the B&M stacked plate cooler but it's routed through the radiator...

Resq302:  Thanks for your words of caution.  I wished I had solicited input about the repro shroud before I bought it.  I'll keep a watch on that.

All, thanks for your comments and suggestions.  I'll follow up on a couple things but remain prepared to just manage it.

[stripedelete]

did the same issues exist 40 years ago? 

[Charger-Bodie]

Ive been told my many people that back in the day it was a common site on a hot night ,to see cars lining the streets to do whatever in town and for there to be a puddle of collant under alot of them. Before overflow bottles anyway.

[Cooter]

did the same issues exist 40 years ago?  

No, but I'm sure all the 440's 40 years ago were over bored .030-.060, had compression increases, larger valves, ported heads, large, open plenum aluminum intakes, huge Holley carbs, headers, ran on 87 Swill pump gas,  and big honkin' roller cams too....

[resq302]

Don't forget that todays crappy gas' can screw with your engine and raise engine temps courtesy of the ethanol in the gas.  A couple years ago, gas seemed to last forever without having to add fuel stabilizers to it, now they say you are lucky to get  3 mos out of the gas even with using the stabilizers.

[stripedelete]

did the same issues exist 40 years ago?  

No, but I'm sure all the 440's 40 years ago were over bored .030-.060, had compression increases, larger valves, ported heads, large, open plenum aluminum intakes, huge Holley carbs, headers, ran on 87 Swill pump gas,  and big honkin' roller cams too....

Wow, ahead of their time,,,, I guess.