Heating problem - need help

[HemiTime]

I am having a heating problem with my street driven 66 Dodge Charger Hemi.  The Hemi is 549 cid 725 hp @ 6000 rpm - 694 lb-ft @ 4600 rpm and run on pump gas.  I have a "Be Cool" radiator with dual fans and stock water pump.  I was researching changing over to E-85 with a Ethanol Carb to see if this would help with overheating while driving on the street.  The guy at C & S Ethanol Carb told me to first try changing the timing.  My timing is 32 degrees, he said to set it to 45 degrees and on my MSD Ditigal 7 change the retard to 13 in 1,2,3 gear at 2600 rpm.  This would put my timing back to 32 degrees when at 2600 rpm or over but when under the timing of 45 would help the engine run cooler with stop and go driving on the street.

Anyone ever try this or does this make sense and if so why??

Thanks for any help you can give me.

HemiTime

[Musicman]

Have thought about changing over to a high volume water pump and a balanced sleeve high flow thermostat? B-Cool radiators are nice... what size are you using? Is the heating issue showing up around town, on secondary roads, on the highway at upper rpm speeds, all of the above?

Timing does affect temperatures, as does the fuel mixture, but it helps if you know some of the details first.

I know a fella over at 66-67charger.com that would just love to hear about that 66 Hemi your driving.

[HemiTime]

Thanks Musicman

I have a Dual 1" Core "Be Cool" ...think part of my problem is that this radiator is rated for 400 HP.  I only experience heating up when in town stopping at stop lights and driving slow.  If I drive on the hwy it stays at about 180 degrees.  I have also thought about an Electric water pump which might help.  Tell me more about a Balance Sleeve high flow thermostat...have a 160 in it now.

[Musicman]

WOW  That sure is purtty 

Yup, I agree... that radiator you have looks to be almost stock in size. Probably a great radiator for a mildly built 383 or a stock 440, but that big honk'n monster of an engine you have there definitely requires something a little larger. I'm guessing a 27"... Check with the folks at B-Cool, and see what they have to say.

A 160 degree thermostat is great if the cooling system will support it, but it isn't worth a dam if the rest of your cooling system isn't capable of dissipating the excess heat fast enough to keep up with it. In other words, if the water in the radiator isn't being sufficiently cooled below 160 during a normal cycle, then the thermostat will remain open and the coolant will just keep cycling around the system, only briefly being cooled a few degrees as it passes through the radiator on it's way back to the hot block.

HV Water Pumps...
A high volume water pump will move more water through the block at low rpm's (downtown traffic, etc). The extra flow means more heat is carried away from the block to the radiator, which results in greater cooling efficiency.(assuming the radiator and fan assembly are up to the task)

High Flow Balance Sleeve Thermostats...
Normal thermostats are designed to open against the flow of water from the engine, so the coolant flow pressure has a direct effect on the thermostat's operation. With high-flow water pumps, the pressure differential can be enough to cause a change in the operational opening rate of the thermostat. Balanced flow thermostats use a balanced sleeve design, which results in equal pressure at both sides of the valve, so its operation is only regulated by coolant temperature. High flow balanced sleeve thermostats sold by Milodon and others are recommended when using a high-flow water pump, to prevent the added pressure of a HV pump from trying to hold the thermostat closed longer.



Mike 

[Musicman]

By the way... what kind of temps are we talking about here? You said the car maintains 180 on the highway... that's very good news, and about what you should expect... but what about around town? As you know, downtown you don't have all that cool air whipping around in the engine compartment, or being forced through the radiator like you do on the highway, dissipating heat and keeping everything nice and cool. Downtown you are relying solely on your radiator and fan(s) system to dissipate heat and cool things down.

[oldschool]

I am having a heating problem with my street driven 66 Dodge Charger Hemi.  The Hemi is 549 cid 725 hp @ 6000 rpm - 694 lb-ft @ 4600 rpm and run on pump gas.  I have a "Be Cool" radiator with dual fans and stock water pump.  I was researching changing over to E-85 with a Ethanol Carb to see if this would help with overheating while driving on the street.  The guy at C & S Ethanol Carb told me to first try changing the timing.  My timing is 32 degrees, he said to set it to 45 degrees and on my MSD Ditigal 7 change the retard to 13 in 1,2,3 gear at 2600 rpm.  This would put my timing back to 32 degrees when at 2600 rpm or over but when under the timing of 45 would help the engine run cooler with stop and go driving on the street.

Anyone ever try this or does this make sense and if so why??

Thanks for any help you can give me.

HemiTime

thats a nice looking engine bay,hemi time.first off,32* timing,is that enough? did you have it dynoed?i have 3 500" and 1 572" wedge motors,mine all like 35-36* timing.not enough or to much timing could make it run hot.
i use mancini's dual 1" tube aluminum radiator on my 572,with a stock fan shroud and stock clutch fan.it dynoed 670 hp at the wheels,and has 13.7 c.r. so it makes alot of heat. i have never had any cooling problems with it. i drive mine mostly on the street, have never over heated.i can drive all over town in stop and go traffic and never get above 200*,even on 90* plus days.i use a 180* thermostat,mopar aluminum water pump,and it does really well.

[firefighter3931]

Hemi engines generally don't need as much advance as a wedge.....32* should be in the ballpark. You might need more timing at idle....like 18-20* so that means limiting the mechanical advance to 12-14*

The carb might also be lean and need some tweaking. I would get it onto a chassis dyno with a wideband o2 sensor to see what the EGT's are showing. Elevated exhaust gas temps indicate that the mixture needs to be fattened up. 



Ron