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  #1  
Old 04-15-2007, 11:49 PM
tdaver tdaver is offline
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Default 440 overheating and tuning problems

Hi Folks,

Thanks to everyone so far for their advice in getting my 440 up and running. I worked a lot with my buddy this weekend and am still stuck on a few things. Sorry for the long post but I am hoping with lots of info to get lots of feedback. I am still having one big problem: overheating. It runs at about 190C at idle but when I start pushing the RPM's up over 3000, it quickly jumps up to 230C and will just boil and keep climbing if I don't shut down.

I have a 1972 Dodge Charger. Engine is a newly rebuilt 440 from a 1966 Chrysler Imperial. Bored 0.30" over with stock (oversize) pistons, steel rings. 516 heads with 1.74" exhaust valves and hardened seats. The compression ratio is about 9.5:1. Cam is a COMP Cams XE274H (duration 230/236 at 0.05" and lift 0.488/0.491) and TCI breakaway torque converter. 3.55 rear end. Water pump is the aluminum pump and housing from 440 source. New 26" stock replacement radiator (3 core) with shroud. 13 psi cap and overflow only. 180 deg thermostat verified working properly. 7 blade stock metal fan with new thermostatic clutch. Front of fan is 2 inches from radiator and the fan is about halfway into the shroud. No A/C and I replaced the pulleys on the crank and water pump with the non-A/C versions from Year One. Distributor is remanufactured MOPAR stock electronic unit. I have replaced the stock heavy spring with the light aftermarket one to get the timing up at lower RPM's. 625 cfm Carter AFB carb with stock iron intake.

I realize that this carb is undersized and hope to replace it soon. I just had it around and used it to get things running. I suspect timing and carb issues. I have no idea if the carb is causing problems. As for timing, I have my timing set at about 10 degrees at an idle of about 1200 rpm. The engine seems to be strong and doesn't detonate.

HELP needed from the salty old MOPAR dogs!!
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  #2  
Old 04-16-2007, 12:02 AM
crisser crisser is offline
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A lot of new engines overheat. Just take as many short trips till it gets too hot and let it rest. A lot of times this condition goes away as the motor slowly breaks in.
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Old 04-16-2007, 12:55 AM
tdaver tdaver is offline
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Default thanks

Thanks Crisser,

I have heard this too but thought mine seemed extreme. I will keep it slow until it settles down. Hopefully that's it! Either way, I am diggin' this new beast!
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  #4  
Old 04-16-2007, 09:14 AM
Daylong Daylong is offline
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The engine should not get that hot, ever. You may have a bad water pump – remove the thermostat and make sure you have good circulation. You may have a cracked head , casting flaw in one of the heads or you may have a head gasket leaking. Look for bubbles in the radiator and water coming out of the exhaust.

Recheck your timing.

The last thing you want to do is run the engine hot and tear it up.
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  #5  
Old 04-16-2007, 11:58 AM
tdaver tdaver is offline
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Default more info

Thanks Daylong,

I haven't seen anything weird coming out of the exhaust except the passenger side smokes a very little bit at idle. I assume it is oil burning which is probably normal during break in. I haven't noticed any sign of coolant or oil in the wrong place. Oil is so clear it is hard to read on the new chrome dipstick. Radiator fluid is mostly green with a little leftover rust. I can see flow in the radiator when the thermostat opens and it has just a couple of largish bubble float by every few seconds which doesn't seem weird to me. How do you know if your water pump is too slow or fast? What should the number of blades and pulley ratio be for a street engine with a stock radiator?

I am wondering if it is a combination of too much advance at WOT and a possible lean carb. Could this cause overheating? If I keep the RPM below say 2500, it sits at about 190C. I am using a stock Mopar elec. distributor with the heavy spring replaced by a light spring. I set timing to about 10 degrees at idle but I need to check to see where it is at WOT. I just figured since it wasn't knocking it wasn't too far advanced to overheat....
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  #6  
Old 04-16-2007, 01:21 PM
sundrop_440 sundrop_440 is offline
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If this isn't your problem maybe some of my story may help, I built a 440 on a engine stand and then I bagged it and rolled it in the corner of my garage while I finished building the tranny and painting the engine compartment on my restoration 68 charger, it sat for two weeks before I installed it. I fired it up for breakin and had same overheating problems I couldn't let it run for more than 10-15 mins, tops and I was into the 200's. replaced the thermastat, removed the thermastat, recored the radiator, differant fan,and started questioning if I put gaskets in wrong, etc, I removed the water pump and noticed one kernel of corn at the bottom of the housing, I removed the housing and found that a mouse had packed my engine with seed corn just inside the block from the water pump, He either ran down the thermastat opening or up the lower hose opening on the water pump housing, later I saw the little hole in the engine cover bag, I blew compressed air/water back and forth through the heads until it blew clean ( you can't imagine how much corn was in there) buttoned it up and life is good.
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Old 04-16-2007, 01:22 PM
BigBlockDude BigBlockDude is offline
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Make sure your clutch on the fan is working properly. I recored the radiator in my 70 Coronet, 3 core 26 in. and it would still get hot at cruising speed, and higher rpms. I put on a factory non clutch fan and it was fine. My clutch fan must was defective.
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  #8  
Old 04-16-2007, 01:55 PM
sundrop_440 sundrop_440 is offline
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You know I stated that a little wrong, the corn was packed around the cylinders just inside the block from the water pump housing inlet/outlet holes,I wish I could get my hands around his little scrawny throat, I had a beautiful engine and compartment and after I cleaned all that corn and anti-freeze out, what a mess in the comparment on the floor on me the walls, that happened about 6 years ago it's funny now but it wasn't then.Sundrop.
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  #9  
Old 04-16-2007, 03:52 PM
tdaver tdaver is offline
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Default corn, mice and fanclutches

Sundrop_440--I sure do hope I don't have mice or corn! Wow! I do get the message that there might be something blocking the flow. I did clean things well and reassembled quickly after.

BigBlockDude--how do I know if the clutch is working right or not? I would be happy to do a test if I knew what to do. The fan seems to always be spinning and the clutch is a new, regular duty clutch from Summit.

One more thing, I discovered my lower radiator hose has no inner coil spring. I read on another thread that it could be collapsing at high flow (high RPM). I ordered another hose today. Hopefully this will help.

I appreciate all of the feedback...keep on postin' and I will update you.
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  #10  
Old 04-16-2007, 07:14 PM
crisser crisser is offline
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If the cooling system checks out ok, try adding about 4 degrees more timing at idle. Iv`e been a mechanic for about 23 yrs. Iv`e seen many engines run hot for a time after a rebuild including mine. They still run many years later. I agree 230 is getting too hot. I think some builders run too tight of a piston fit and not enough ring gap causing heat. It will loosen up with time.
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  #11  
Old 04-16-2007, 08:30 PM
tdaver tdaver is offline
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Hi Crisser,

Thanks again. When you say add 4 degrees of timing at idle you mean from 10 to 14 degrees? I would think advancing the time would make things worse and cause more detonation at high RPM? No? Educate me please. I'm listening.
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  #12  
Old 04-16-2007, 08:49 PM
crisser crisser is offline
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Yup. from 10 to 14. Too little timing causes the engine to overheat. But you are correct that too much causes detonation. There`s a fine line. Trying to troubleshoot over the computer is a b!tch. I`m just asking you to try to set it there to see if the engine responds by cooling down some. The mark on the balancer could be off causing false readings.
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  #13  
Old 04-16-2007, 08:55 PM
crisser crisser is offline
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By the way, i run all engines with comp. cams around 12 degrees at 800-900 rpm. This is not a stock engine anymore so screw the chilton manual as far as tune up specs go.
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  #14  
Old 04-17-2007, 09:40 AM
BigBlockDude BigBlockDude is offline
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Quote:
Originally Posted by tdaver View Post

BigBlockDude--how do I know if the clutch is working right or not? I would be happy to do a test if I knew what to do. The fan seems to always be spinning and the clutch is a new, regular duty clutch from Summit.

Do you have a non-clutch fan you can try.
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  #15  
Old 04-17-2007, 10:33 AM
dusterrcr dusterrcr is offline
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Pull the plugs and see if its lean.
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  #16  
Old 04-17-2007, 09:44 PM
tdaver tdaver is offline
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Default big update

Hi folks,

Thanks for sticking with me here. Here is a big update. Bottom line, still overheating. I have verified with a TDC tool that the harmonic balancer has not slipped so at least the timing I measure is correct. Also inspected plug one at that time. It looked very normal. It was whitish-brown, clearn insulator and brownish electrode. Replaced the lower radiator hose with one that had a coil in it after I discovered it didn't have one. Measured the following timing curve.

1000 RPM 4 deg
1200 RPM 6 deg
1600 RPM 15 deg
1800 RPM 18 deg
2000 RPM 25 deg
2200 RPM 25 deg
3000 RPM 25 deg

Looks like mechanical advance is about 21 degrees and is all in by 2000 RPM. So, I increased the timing to 32 deg at 3000 RPM and measured it to be 9 deg at 1000 RPM. The car still didn't detonate at higher RPM. Maybe I need more advance?...

So, I start the car, it warmed to 190C. Took it for a short drive, mostly under 2000 RPM but put my foot in it a couple of times. The temperature creeps up until it over heats in about 3-5 minutes. Reaches 230C and will continue to climb quickly if not shut down. Took it home, cooled it off, started it again. At 190C I let set the idle to about 2000 RPM and in the driveway it slowly heated up and began to overheat.

When I look in the radiator at idle I see flow start as the thermostat opens. Smooth flow with some largish bubbles. If I increase the RPM to 2000, flow increases a lot and I can see it coming into the radiator much faster, like a strong hose for lack of a better description. So I suspect at even higher RPM it is really flowing like a firehose. I have a 6 (curved) blade, high flow water pump from 440 source and am using a pulley that is larger than the one that it had before I removed the A/C. I still don't know if the water pump is flowing at the right speed. I could try putting on the smaller pulley to slow the pump but have no real idea if this is the culprit.

One thing that comes to mind is that the front of the fan clutch is located too far from the radiator and isn't kicking in soon enough. I don't know how to check if it is engaged at high temp. When it is cool, it spins freely by hand (engine off). The front fins of the clutch are 1.5" from the radiator which has a shroud.

Next step will be to advance the timing in small steps to see if at some point it runs noticably cooler. Still listening.... Any more thoughts?
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  #17  
Old 04-17-2007, 09:54 PM
crisser crisser is offline
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How far is the clutch from the rad.? Can you feel heat coming from the fan?
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  #18  
Old 04-17-2007, 10:03 PM
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You could have too much coolant flow from that 6 blade pump. The coolant may not be in contact with the engine long enough to absorb heat and then transfer it to the radiator. This has been discussed before. The speed of the pump may also be too fast. There is a product called Water Wetter and it enhances the properties of engine coolant. Might be worth a shot. Other considerations are fan clutch and spacing of the fan and shrouding.
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  #19  
Old 04-17-2007, 10:52 PM
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superbee1970440 superbee1970440 is offline
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Quote:
Originally Posted by tdaver View Post
I still don't know if the water pump is flowing at the right speed. I could try putting on the smaller pulley to slow the pump but have no real idea if this is the culprit.
If you install a smaller pully, the pump will spin faster.

I agree with Dick. You could have too much coolant flow. Just a thought.

Sam
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  #20  
Old 04-18-2007, 01:15 AM
tdaver tdaver is offline
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Default fan clutch and water pump

Many continued thanks for the feedback.

The front of the fan clutch is 1.5 inches from the radiator, which has a shroud. As for the water pump, I also agree a smaller pulley makes it run faster....my mistake. The pulley on there now is the one for a no A/C car and it would not be possible to put any larger pulley on there without hitting the crank pulley. I don't know how to know whether my water pump is pumping too fast or not. I suppose I could buy a "standard" 440 water pump. i.e. not high flow, no curved blades, just an ordinary 6 blade pump.....

I am going to figure out how to test the fan clutch somehow and read up on how close it should be located to the radiator.
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Old 04-18-2007, 01:46 AM
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Biggrin

There was a thread here a while back that advised of the differences between water pumps for an A/C vs non A/C. Maybe someone remembers the thread.
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Old 04-18-2007, 01:54 AM
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I found it. Actually, I found several, but this thread has good info. Pay heed to post #12. It was in this thread that I learned of the difference between A/C and non A/C water pumps. John is good.

http://www.moparchat.com/forums/show...FC+water+pumps
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  #23  
Old 04-18-2007, 03:25 AM
tdaver tdaver is offline
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Default fan and pump specs

Ok, I read the suggestions and here is more info. The FSM for a '72 Charger with an automatic tranny calls for a 18.5" fan with either:

a 7 blade fan with 2.5" blades and a Thermal Drive (California)
OR
a 5 blade fan with 2.31" blades and a 2"spacer

I have a thermal clutch which I assume is what they mean by thermal drive. My fan is 18.5" in diameter and it has 7 blades, but they are about 4" wide! It is the original steel fan from the 1966 Chrysler Imperial that I got my engine from. It had a broken thermal clutch attaching it to the engine. So, I replaced the clutch and used the fan. Maybe this poor standard duty thermal clutch can't turn this big fat high-drag fan..... Sounds like a fan with about 2.25" blades might be better (and lighter).

Additional information: Neither the instructions that came with the thermal clutch or the factory service manual specfies how close it has to be to the radiator. FSM also says the non-A/C pulley ratio should be 1.17 which I believe I have. It also says with or without A/C, the water pump is a 3.70" diameter, 6 blade pump. I have a pump this size but as I said before, it is rated as a high flow pump with 6 curved blades to reduce cavitation.....

Also, I know I must not be the only guy running a street 440 with no A/C and a standard 3-core radiator. Anyone out there want to share their water pump, fan, clutch, etc that IS working and what temp do you run at.
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Old 04-18-2007, 10:32 AM
dusterrcr dusterrcr is offline
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Plugs are whiteish brown?---I like to see them a nice grey,Just trying to turn black.Have always found 440,s happy to be a tad rich as opossed to a tad lean.Even a little black doesnt bother me.Would be easy enough to jet up just to see if theres any improvement.
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Old 04-18-2007, 10:55 AM
matador60 matador60 is offline
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If the heater is hooked up. Have you tried to run it with the fan on high
to see if it helps. If the heater in not hooked up do you have it blocked off
or the hose from running water from the inlet to the outlet. If you have the latter you are running hot water with out cooling it back into the motor.
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Old 04-18-2007, 01:59 PM
Daylong Daylong is offline
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I agree that you may be flowing the coolant too fast through the radiator to transfer the heat to the air. There is also the possibility that the head gaskets are designed for racing and allowing too much flow. I doubt that a high flow pump is your problem.
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Old 04-19-2007, 05:08 AM
tdaver tdaver is offline
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Default gaskets and heaters

The head gasket is a Fel-Pro standard gasket from the engine rebuild kit. Nothing special. The heater is connected and working. I can't really tell if it makes any difference to run the heater....more to come.
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Old 04-21-2007, 09:29 PM
tdaver tdaver is offline
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Default update

Hi folks,

Here is an update, bottom line, no luck. Once the car has surpassed about 190F, it will just keep slowly climbing into overheating whether sitting at idle or driving. Today I have tried these things with no change in cooling:

Setting the timing back and forth by a little then a lot.--no change.

Inspected 6 of 8 spark plugs, insulators are white and brown. Maybe too lean? Not an expert here.
Set carb idle mixture from very lean to very rich and also ran with choke mostly closed. Note that when changing the idle mixture, I was at about 1000RPM and there was no change in the idle over the entire range of the mixture screws. It still overheats at idle. Note that the carb is a Carter 625 cfm.

I taped the fan blade to radiator shroud to test the fan clutch. Fan stayed still until about 190F and then broke free and spun.
Tried running with no thermostat. A little worse if anything.
Used "Water Wetter". No change.
Pulley ratio is about 1:1 (hard to measure with belts on). This is close to the value stated in the FSM.

I have an infared thermometer from work that I used to check temps as it began to heat up. With the engine temp guage reading about 200F, the headers, right at the head, were between 800-1000F. The heads, near the plugs were 250-300F. The intake manifold was 250F and well over 300F at the exhaust crossover. (My crossover is not blocked, stock steel intake) Both radiator hoses were at about 160F. This radiator has the tranny cooler in it and I checked the tranny pan and it was 160F. I interpret all of this as the radiator cooling OK, but the block/heads themselves are just getting really hot. Does anyone know if this hot exhaust crossover could be my problem?

My buddy has an Olds 442 with a built-up 425 in it. Fast car with a comparable build to my 440. It runs consistently at 160-170F. His exhaust headers were about 600-800F, heads about 200F, and intake at 160F. Cooling system on his car is stock. He is clearly running much cooler...

I have ordered a new "stock" iron water pump, but I honestly believe the one I have from 440 Source is fine. Flow is gentle at idle and increases with RPM.....Still no signs of a coolant/oil leak from a engine crack or leaky head gasket.

Did a compression test on the hottest two cylinders and both read about 175 psi.

I am really lost and out of ideas. I believe I have tried nearly everything that has been suggested.... HELP!!! ANYONE???
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  #29  
Old 04-22-2007, 06:24 PM
wilks3 wilks3 is offline
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Hi, I have 69 Charger, .060 over 440, 4-speed. A new 22" 3 core radiator, home made shroud, 16" flex-a-lite fan. Car runs 185* to 190* down the road, hasn't got above 210* idling. Have read all posts, two things to try. Borrow a carb you know is working right and try it. Might be something internally wrong with yours. Second, did you use the heat gun on the radiator? Maybe left over crap in block broke loose and plugged "bottom" cores. Is the gauge for sure right? When it overheats, does it boilover? Is your antifreeze mixture 50/50? Have you tried pure distilled water? Hope any of this helps.
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  #30  
Old 04-22-2007, 09:14 PM
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mopar413 mopar413 is offline
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A couple of friends and myself years back had a 63 Ford galaxie 427 dirt car.When we put the engine in, the thing would gradually get hotter til it overheated. I tried a thermostat,took the pellet and center out of the thermo..I then tried making some discs from aluminum the size of the thermo with various size holes in the center,if i recall correctly(been a long,long time ago)i ended up with a 5/8 hole in it. An old flathead trick. Did you check for a vaccum leak between the intake and the heads, dribble carb spray on where they bolt together, if it speeds up you have a leak. Were the heads cut very much if any? Was the blocks water passages cleaned really good? Im done.
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