440 overheating

[65 pacecar]

I need some help once again! I got this 440 all together and it runs awesome!! but it wants to overheat after about an hours worth of running! I have tried 2 different (good) 3 core radiators with 16in electric fan to help, with the original fan and without with and with out a shroud, New head gaskets (not leaking), 160 and 180 thermostat,Timing set @14 degrees. headers with 2.5 in exaust, I was going to try an oil cooler next . Motor is a 440 .60 over .484 cam 906 heads edelbrock dual plane intake , holley 770 avenger, msd box, distributor,and wires, . Has about 50 miles on it . Thank you to any one that might have some ideas or info for me!

[dwc43]

That rad is plenty big for what you have. If your running those fans, make sure they are on the back side of the rad so it wont restrict incomming airflow from the grill. You need to check your pulley ratio and make sure your not turning your water pump too fast. Also recheck total timming and your carb jetting. Too small a carb or too lean will cause over heating. You need at least an 850 with what you have. The stock Thermoquad for a 440 is rated at 850 as well. IT would make a good carb for your set up for yours.

[65 pacecar]

Thanx! I will check on all that monday! How do you check total timing?

[rr69half6bbl]

hey 65, a couple of things that helped on my overheated 440 were the antifreeze, did you put in a 50/50 mix of anti and water? just water or just anti freeze ounce it gets hot takes longer to cool down in the rad. and the timing, i run mine at 10degrees before tdc, it isnt as crisp when you get on it but it does run cooler on the pump gas and starts a whole lot easier,and I agree with dw on the carb thing, you need at least 800 cfmfor that big an over bore adn cam size,.
and your air cleaner,you arent runnin a neat looking but restrictive air cleaner are you?I highly recomend a k/n filter and an open sided typr air cleaner,your carb may well be a 770 but if it aint gettin enough air , it isnt gonna flow 770 , happy moparing doug

[65 pacecar]

Thanx doug ! Ill try changing the timing a bit too. And ill surely try a bigger carb!

[dwc43]

Originally Posted by 65 pacecar

Thanx! I will check on all that monday! How do you check total timing?

You need what's called a dial back timming light. A light with a knob on the back of it. You need to plug the vacuum advance line and never use it again. IT puts too much advance in during cruise and this may cause your touble as well. Performance engines don't need it. Raise the idle to about 2500 so that the mechanical advance is fully advanced. Now hook up the light and set the knob to 34* and flash the dampner. Turn the dist. until the line on the dampner is sitting on zero. Now return the engine to idle. Turn the timming light dial back to 0 and you can see what your intial timming is. Lets say it now reads 16, but after you get to 2500 and the advance is figured in it will read 34* again. Hope that exsplains it well enough, if you have any questions, just ask.

[dave571]

I really doubt the 770 carb will cause the over heat.

First off, a small carb won't cause a lean condition. It causes a shortage of air AND fuel (a lean condition is a shortage of fuel only) The 770 will be a little shy of air/fuel above 5 grand on that 440, and that's about it.

Some how a 750 feeds my 440 into the 11's, so I wouldn't worry about the carb affecting the overheat.

The carb could be lean, but not because it's not big enough. More likely because it's not jetted right.

Read the plugs. If they look lean, jet it up a couple of sizes, and go from there.

A fresh motor will sometimes run hotter than you like. Some things to try.... There are some choices in water pump configuration. Ask at the auto parts store, as some have bigger impellers than others.

A 4 core rad may help(an expensive trial an error thing though). An additive like "water wetter" may help also.

How hot is it running?

[65 pacecar]

Once it starts to get over about 180 it just keeps climbing but I didnt let it get much over 210. If I let it just sit and idle it will take almost an hour but if i run it on the freeway its got about 15 minutes to get to this point.

[dwc43]

Sounds like one of a couple of things. Carb size and/or jetting, timming issue, or the wrong pulley ratio. Stock pumps tend to cavitate at 4000 rpm so you may need to slow the water pump speed down so the water has time to pick up the heat transfer from the engine.

[dave571]

Originally Posted by 65 pacecar

Once it starts to get over about 180 it just keeps climbing but I didnt let it get much over 210. If I let it just sit and idle it will take almost an hour but if i run it on the freeway its got about 15 minutes to get to this point.

Have you tried running it without a T-stat?

I realize that normally this would make an overheat worse, but it would be interesting to see the results.

I broke an old T stat, to use it as a restrictor plate in mine. I think it ran cooler without it than it does with it. Not much difference either way.

I had a customers car that wouldn't run cool with a tstat in it, no matter what we did to it.

[Dick]

Originally Posted by dave571

Have you tried running it without a T-stat?

I realize that normally this would make an overheat worse, but it would be interesting to see the results.

I don't understand that statement. The thermostat only helps maintain minimum operating temperature and it will open and close to stabilize that temperature at whatever degree the thermostat is calibrated for. A 180* stat will open fully about that temp and will not start to close unless the coolant temp drops enough to be out of range.

Running without a thermostat should not make it run hotter.

An exerpt from How Stuff Works:

The thermostat's main job is to allow the engine to heat up quickly, and then to keep the engine at a constant temperature. It does this by regulating the amount of water that goes through the radiator. At low temperatures, the outlet to the radiator is completely blocked -- all of the coolant is recirculated back through the engine.

Once the temperature of the coolant rises to between 180 and 195 F (82 - 91 C), the thermostat starts to open, allowing fluid to flow through the radiator. By the time the coolant reaches 200 to 218 F (93 - 103 C), the thermostat is open all the way.

[dave571]

Originally Posted by Dick

IRunning without a thermostat should not make it run hotter.

An exerpt from How Stuff Works:

[/B]

I am well aware of how a t-stat works.

Having no tstat making a car run hotter, does not contradict anything you have posted.

It does usually make it run hotter. It isn't uncommon at all.

Why? Because water/coolant does not transfer heat instantly. The water/coolant needs time to transfer the heat from the engine.

Besides aiding in warm up, the thermostat serves the purpose of restricting the flow of the coolant, so it will absorb the heat. This is why race cars often use an item called a "restrictor plate" It is open all the time, but restricts the flow to improve cooling efficiency.

Many who remove tstats experience overheat. A lot depends on the system. My big block pick-up will run so cool that the temp doesn't come up on the gauge without a tstat. My old bb van would overheat faster without one. My drag car doesn't seem to care either way.

[Dick]

Good points, Dave. I can understand that if the the radiator was old and had buildup inside and outside. Yes, the coolant does need time to absorb and dissipate heat. The same principal applies to A/C. Sometimes slowing the blower down increases the cooling in the cockpit because the slower moving air over the evaporator has a chance to be cooled down.

I guess my response was based on the statement that "normally" running without a T-stat would make overheating worse because I personally wouldn't consider that normal.
However, if it works sometimes.......................................

Along those lines, Water Wetter would probably help cool things down a bit.

[65 pacecar]

Thanx for all your help Guys! It was the total timing! It was only at about 24 degrees total timing @2500 rpm So I changed the springs and that other peice in the Msd distibutor and started with the total timing set @ 34 degrees and when I brought the idle back down to 850 rpm it cam in @12 degrees. I also added some water wetter. Man and I thought it ran good before what a difference. Hey thanx again for all your help