View Full Version : HELP!! 440 overheating!!

04-07-2013, 08:54 PM
i have a dodge ram pickup 440/727 4x4 i run on and off road. here is my issue. last year i put my clutch fan thru the original copper brass radiator so i replaced it with an aluminum radiator and a 16" electric fan. i have the fan mounted right to the radiator no shroud. driving around town is great right around 180 degrees no problems at all. get on it hard or go full throttle off road or sit in traffic even with the fan on starts climbing fast and never seems to recover unless i can drive in open air. today i shut it down about 230! i need to get this thing under control before i cook my $8K motor in this truck. back to mechanical fan and fan shroud? bigger electric fan? take t-stat out? anything to keep temps down! it currently has 185 thermostat in it. Please help any ideas or photos of quick home remedys please shoot them my way. I have a big trail ride next saturday that I want to make and not have to get my rig towed off the trail from failures. :help:

04-08-2013, 01:08 AM
A shroud will do wonders for you. I had the same problem. I was running a Afco aluminum radiator with a 16 inch electric fan and had same problem. Finally went with a Cooling Components fan made with the shroud and no more overheating problems.

John Kunkel
04-08-2013, 05:53 PM
I agree, a shroud-mounted electic fan is infinitely more efficient than a core-mounted fan.

04-08-2013, 10:48 PM
so i made a shroud tonight. attatched the fan to some aluminum, cut 2 square spots out for hwy air to flow thru without the fan being on, and mounted it about 1/4" off the radiator. someone told me that it needed to be mounted further away from the radiator or its not helping at all. any truth to that?


04-09-2013, 01:00 PM
I dont know exactly where the fan should be located in relationship to the shroud but I believe it makes a big difference where it is mounted in the shroud and how far it is from the radiator for maximum cooling. I also had made a shroud before buying the Cooling Components unit which is fan and shroud combined. My homemade version did not cool near as good as the Cooling Components one and I'm sure the fan was too far in or out of the shroud.

I thought I had all kinds of problems before getting the right fan shroud combo. I went to three or four different electric fans and back to a mechanical fan but did not have a shroud. The shroud was my answer.
I should have figured that out sooner. Finally I was talking to the guys at Walker Radiator at a show and they asked the the question. Do you have a shroud?

John Kunkel
04-09-2013, 04:19 PM
I don't think 1/4" away from the core is much better than no shroud at all; I'd want at least an inch to form an efficient plenum.

The flow-through holes defeat the purpose of the shroud, they should have a flapper on the engine side that will suck shut when the fan is running.

04-09-2013, 05:46 PM
did you look to see if the fan is turning the right way ,sometimes the motors will run backwards or were set up to push air mounted on front side of rad.I run into this a lot on transit bus a/c units,after some one crossed wires,also late engine timming can cause overheating ,no vacuum advance with sticking weights limits timming this is allways the last thing most people check and the cheapest just get out your timming light.

04-09-2013, 08:02 PM
Make sure the lower radiator hose isn't collapsing under high RPMs.

04-10-2013, 12:10 AM
ok. yes i did put rubber flaps on the flow thru holes, fan is connected to pull correctly, never noticed lower hose collapse either, and tonight i re-made my mounts and now is 1 1/4" away from the radiator sealed all the way around. noticeable pull in air flow thru the radiator now. put a small piece of paper in all corners of radiator and stuck right too it. gonna go with this and see what happens this saturday and i'll let you all know how it worked. :dude:

04-15-2013, 09:38 PM
well...good news is the fan shroud worked wonders! never got hot on the trail at all this weekend! Fan tastic! get it fan? cooling joke. anyway in the midst of 500hp and a stock dana 44 front axle I happend to destroy my axle shaft while on this trail ride so my day was cut short for riding and 3 hours to recover and remove my rig from the trail. But the engine never over heated lol.:thumbsup:

04-17-2013, 01:13 PM
Sounds like you fixed it. Here is a tip: For peak fan performance, 1/3 of the fan blade should be inside the shroud, 2/3 of the blade should be outside.

Raynor Bain
05-19-2013, 12:37 AM
hello i have a 1966 fury wagon with a 440 i have had the car about 15 years and have always had a cooling issue so i finally decided to completely over haul the engine i had the block and heads hot tanked bored 30 over speed pro flat top comp 509 cam 346 heads torker 11 intake holley 850 all msd ignition headers 28stall new champion 3 core rad 2 10 in elec fans with shroun that covers rad new aluminum pump and housing hi flow pump 180 t stat timing set at 34 total and 12 base set card rich still gets up to 230 when i shut her down doesn't matter if i am in traffic or on open road before over haul it ran 210-215 i just do not under stand how nothing but upgrades and prob gets worse block is a 1969 and heads are 1971 is their a difference in heads or head gaskets that don't match up the only thing i can figure is their is a flow problem but i can't find it i can flow water hose threw block and radiator don't have heater core hocked up 16 pis cap new hoses made sure lower has spring tried 2 different temp gauges i am stumped just don't under stand

05-19-2013, 11:23 AM
have you tried switching fuels,are you using 93 oct.If you touch upper radiator hose does thermostat open at 180?and what temp do the elect fans come on?

Raynor Bain
05-19-2013, 12:54 PM
i use half and half 90 non eathional and 110 fans are on a switch come on with key tried several diff t stats use a infer red temp gun opened at 175 ish i wonder if that is too soon and water does not have time to cool in radiator before re entering engine

thanks for input

05-19-2013, 04:42 PM
still not fixed. played in the mud a few weeks back now and had no problems hitting 230! so i shut it down and had to let it sit 20 minutes before it was below 180. so let me paint this picture for ya. I have 440cid. aluminum heads, intake, aluminum high volume water pump, 180 stock t stat aluminum radiator electric fan and shroud. still hot, swapped in a high flow t stat today and it runs hotter than before even driving down the road with all kinds of air flow thru it. Am i correct to assume the high volume pump is flowing too fast and the radiator doesnt have time to do its job? I see guys with mud trucks with mechanical fans and no shroud and they never over heat. just having a good ol time all day and i get 15 minutes of fun and have to sit 20 minutes to cool.
stock water pump and stock thermostat the fix here??? i'm really getting fed up with this high temp problem........:help:

05-19-2013, 05:28 PM
have you run a compression test? how much compression does each cylinder have .what sparkplugs are you using?it can be pre ign.

Raynor Bain
05-20-2013, 09:55 AM
Wow shounds like we in same boat
I use auto lite 85 gap at .40 I do have too high comp bout 195 per cylinder cranking compression preingtion goes away when I mix in race gas
I have tried stock and high flow water pumps makes no difference

05-20-2013, 01:15 PM
Incorrect timing can contribute to overheating issues.

05-20-2013, 06:14 PM
camshaft over advanaced ,

Raynor Bain
05-20-2013, 06:43 PM
timing at 34 total 12 base cam is set up dot to dot is their different head gaskets frome year to year that may have different coolant passages

05-20-2013, 10:56 PM
installed napa new standard flow water pump and 160 t stat tonight sat at idle and never went over 190......gauge is correct,used inferred heat gun to confirm readings, timing 12 base. cam is set up straight no extra advance.also use the edelbrock heads suggested champion plugs and a 35 or 40 gap cant remember. seemed to be a 30 degree drop in temp from upper hose to lower hose in radiator tonight. gonna take it for a ride tomorrow, had a long day at work and ran late so getting it running was enough for tonight but i may have found something to work for me......maybe:whack:

05-21-2013, 10:16 AM
on a copper rad you only get a 15 to 20 deg drop,alum about 30 deg so that looks right ,what color are your spark plugs all white would be pre ign or very lean.did you post the cam specks,? i might of missed it.the only engine blocks I know that were different were the mid 70's motor home blocks they had a figure 8 cooling system passage ,they might use a different head gasket,(they keep burning up spark plugs when mopar leaned them down for emissions)

05-21-2013, 11:31 PM
plugs are a bit white. i have a 750 holly dbl pumper pretty much out of the box, adjusted idle circuits and added spring needle seats for off road. other than that no changes to carb. cam is a huges engines .569 int .576 ext lift 246 durations 108 lobe seperation. installed dot to dot on chain.

05-22-2013, 01:03 PM
I'd look at possible changing power valves, stock is likely a 6.5, and I'd bet you need a 5.5 or a 4.5. Second, if you have stock jetting in it still, I would look at going richer 2 - 4 numbers front and back. Some (or a lot) of your heat issue can be from running lean.

05-22-2013, 06:56 PM
looking at your cam spec's you must be around 11 1/2 to 1 on compression or higher with that big of a camshaft and still have 195 psi cranking pressure,I would go with the suggestion of power valve,jets also check the fuel transfer slots right above the hole for for idle mixture adjustment this is were most of the fuel comes from when your cruising at light throttle,(just blow through it with air) do you have adjustable air bleeds you could put smaller ones in.

Raynor Bain
05-22-2013, 08:51 PM
4.5 power valve only got bout 10 psi vacume 72 in the front 74 in the back jets plugs look little rich air bleeds not adjustable has old holley 850 tried different card off friends 454 holley 750 mide no differance

some times i wonder if i have some kind of casting problem with block water cant flow i talked with machine shop when i was having block work done he told me he has come acrose a couple 440 that he could never get cool after overhaul and some run 180 tops with same parts he told me to start over with another motor went to differend machine shop they said never heard of that checked my block and heads said no problems

05-22-2013, 10:17 PM
I remember reading an article a while back about two different head gaskets for the big blocks and interchanging them would cause overheating. Wish I knew where I read that though.

Raynor Bain
05-22-2013, 11:37 PM
i really think i have somthing mismatched when i bought the car the owner had a recite for the motor was a crate motor in 1971 the block is dated 1969and numbers on heads are 1971 wonder if i need a different gasket

Raynor Bain
05-22-2013, 11:50 PM
are i wonder if their is different pullys and i have somthing mismatched their

thanks for all the help guys

05-23-2013, 11:05 PM
stepped up my jets front and rear and my local parts stores only had a 5.5 power valve in stock so i put it in hoping every little bit helps. I also watched some holley carb tuning videos and according to there info i need the 4.5 valve to be correct. i'm up to 80 front and 82 rear jets on this carb. seemed to run better thats for sure but still not helping cooling sitting at idle. running down the road tonight was perfect never over 180 fan not on. i'm beginning to think my elect fan just isnt large enough. i.e. not enough cfm. 16" 2700cfm rating is what i'm using but everything points to that as the problem......

06-02-2013, 04:18 PM
installed larger electric fan with 160 t stat installed. i can let it get as warm as i want and watch the temp dive back down as soon as the fan is turned on. 18" fan from 80's mustang. who new? no more over heating issue.