Overheating issues in 508

Hi guys,

Finally got the 508 in the road runner and am now trying to determine a slight over heating issue.. I have a 26" 3 core champion radiators with 440source pump, housing on front and 185 stat..

Car keeps cool at first start up and while on cruising on highway, will keep cool, but when doing stop and go traffic, starts to heat up and will overheat ( has not yet)
A few and questions

Engine is breaking in has about 75 miles on it ( just a baby)
I will check heat with heat gun at spots
I suspect 440source pump, will my old cast iron one work better?

Thanks guys,

Generally cool when rolling and hot at a stop is air flow related. You did not mention the fan setup... that is really important at slow speeds.

Another thing to check is tuneup. Adequate ignition advance helps the engine run cool at low speeds. With a performance cam you may need ~20 degrees initial. That and idle/low speed mixture in the ball part (not lean) helps.

Thanks Ahy,

You are a 100% right..
So it is stock location fan, but the champion radiator doesn't have a shroud on it, and previously my old 440 cooled fine without, I plan on adding it going forward..

I will check the plugs and see if they appear leaned out.. I will also bump up initial.

My concern is the 440source pump, I got it before I read some grumbling on here, thought it might be the culprit and thought maybe I should toss it and put the old iron one on from my 440 instead of using it as a paperweight:)

Do you think the lack of a shrould and tuning issues could be the more likely culprit?

Mikey

agree,

Add shroud,
and tune makes a big difference. I have a AFR gauge on my built 383. When I am lean the temp goes up. The AFR gauge was the best investment for tuning the carb.
I have about 20 initial and 36 total. I also have a flowkooler water pump.
Great pump.
I run right on the thermostat for temps most of the time.

the 440 cooled OK with the same rad/fan distance/no shroud? did the 440 have the 'source alum pump? If no on the pump Q reportedly iirc there was a run of restricted 'source pumps way back which has been resolved. a quick pump housing swao including the pump itself if it is a scroll type would ans that. What Ahy said #1-air. I'm assuming same pulley ratio. If it ain't the pump/housing I'm not grasping what is different unless it is the eng but OK at speed pretty much elims the eng & points to air or water speed unless the timing is too retarded at the RPM's it is running hot at

Thanks guys

The old mild 440 had cast iron everything on it, again with no shroud which I will add.
The engine has a quickfuel HR 850 mechanical secondary on it..so if it is flow, would that mean bigger Rad? All things being equal.

Mikey

the rad was fine with the 440 so its OK with the 508, it's something else

Good to know... Thanks Robert, well we will fiddle with tune and add shroud... I also will take a few temp readings and get back to you with those as well.

Mikey

before I get rolling for the day tell me what is different other than the mtrs? same rad same fan distance same hoses same pulleys. Me I'd change out the pump/pump housing first, before I touched the eng, temp gun is OK but you already know it is hot

Forget the pump. There is rarely an appreciable real world difference.

Get a shroud on there and watch your problems go away.

some of the alum housings are restricted/defective (I have one). iirc someone mentioned the scroll type vanes might not flow enough. Plus that'd be easy stuff to check/change. if it was Ok wo the shroud before its OK with it now unless something is fubared in the new eng making it produce way more heat which means the eng is the prob not the shroud

The restrictive housings were corrected 7 or 8 years ago. There shouldn't be many (if any) of those in new stock.

I remember that highly detailed water pump test done on the FMC motorhome with a 440. There was not much difference in water pump volume. All of them moved enough to cool a motor at any regular engine speed.

Pay attention folks, this is a key point.

If you have overheating issues at idle the problem is not likely water flow related.

Heat generated is a factor of HP, period. You might only have 60 more cubes, but how many more HP than the "cooled just fine 440"?

I had a 413 that ran just fine temp wise, then I rebuilt it and warmed it up some. It would overheat at idle and low road speeds, but before the rebuild it didn't do that. I did a bunch of stuff to fix it, even put in a bigger radiator. Nothing helped till I got a shroud then no more issues.

yeah this 508, hopefully makes HP in bunches compared to my nice modest and decent but lower compression 440.

here is the info same pulleys, same distance from the fan, no shroud, different carb, same headers, same smart ass driver too!

Mikey

I have a 400>>499 stroker and I run a Summit 3 row aluminum radiator and dual electric fans. I have the 440 source WP and WP housing and my mess stays cool no matter what. I know people ding the 440Source stuff but so far, I have had zero issues with their cooling parts.

I would recommend that you go with the shroud to really direct that airflow through the radiator as opposed to pulling it from the sides. As stated before, if you are cool while moving but over heating at low speeds/idle, then this is airflow-related...period. You can add all the upgraded radiator/WP/WP housings you want but it won't fix the problem.

Try the shroud first. If that doesn't fix it, might be time to look at a fan upgrade..

A bump in initial timing to 16* or more would also help the cooling overall.

I run a 540" HEMI that made over 600 HP while breaking it in on the dyno. 10.78 compression etc. It runs a max of 15 degrees over the thermostat (Hi Speed freeway for lots of miles). EVERYTHING in the cooling system is factory! The only exception would be a hi efficiency core in the STOCK 26" radiator. Pulleys clutch fan, the works. The shroud is a STOCK repro for the 66' B body, it fits tight. Did you ever notice the rubber that seals the front and back of the hood? Are yours still there? All of this was installed at the factory for a reason, to prevent overheating and warranty expense! The auto manufacturers wouldn't put a $.01 part on a car that wasn't needed! Even though the design is 49 years old, it still works. As mentioned before, the tune up, especially the timing MUST be right as well, but you would want that for performance right?

Heat isn't related to horsepower POTENTIAL, it's related to horsepower USED. So unless you are dragging a trailer now, and weren't with your original setup, the horsepower used in steady-state driving is the same, therefore heat should be the same.

Doesn,t matter if the engine has 80 hp or 8,000,000 hp, if it takes 35 hp to move the car, that's what the engine will make.

R.

Ok, fan shroud is on, took it for a cruise last night. It seems somewhat better but was still warming up to about right in middle of my factory gau. I think it would of kept going

Ok, so shroud helped but did not fix it

Mikey

Ok so parts

Champion 26 radiator 4 core
Fan shroud
17 inch mechanical blade
440souce housing passenger side outlet
440source water pump
Timing 24* initial 34* total


J

It's not that big a pain it the butt , I would swap in your paperweight and see what happens .

Have you run the infrared temp checker yet to see what's hot ? Check the header tube temps at idle .

Are you using a clutch fan ????
Is the fan positioned correctly in the shroud??
are the pulley ratios stock ???

good idea, I was thinking the same thing too John double R! Also, I was wondering if my 3600 stall ptc converter might need a separate cooler to relieve the temp on the radiator.

Mikey

No clutch fan, the fan is close to the radiator, well within the shroud, I believe it is stock pulleys

For maximum effect the fan should be about 1/2 way in the shroud opening.
How many blades on the 17" fan and what style????
How much distance between the tips of the blades and the shroud ID????

Another thing to try is to put a towel on the front of the radiator with the engine idling to try and establish how much air is being drawn across the core.
I agree with the others that it the symptoms indicate inadequate air flow through the radiator

With the hood open you shouldbe able to stand by the rear of the front fender and feel suffient amount of air flowing. If not, you may need a different fan setup. When I had my 440 Challenger I had an 18 inch, 7-blade clutch fan, with a heavy duty clutch and when clutch engaged that setup would blow like mad.
Ron

Adding one is not a bad idea, the added heat load of the trans is not helping, BUT it's not adding much of a heat load at idle.

Check the flow thru the rad first as suggest with a towel.

except change blow to pull

Wrong thermostat 195 degrees required to properly burn today's fuel. Below 195 fuel collects in the intake and burns off in the cruise mode...a-f goes lean. Gee whiz Mr Wizard how do you know that?...Inovate AF gage and experience.

OP where is your temp? See below. Are you at 240?

195 degrees is not hot
210 degrees is not hot
195-215 degrees is normal
220 degrees is warm
230 degrees is really warm
240 degrees is hot

Wrong Fan
use the jaguar [short] fan clutch and the stock fan

Coolant 60% h2o and 40% coolant and the additive like water wetter.

Step one, determine if you have an overheating problem.

You have said nothing for me to believe that you have an over heating problem. It gets up to the middle of the factory gauge has no meaning. Buy a good mechanical gauge and collect real temperature data.

Confirm it, then solve it

A very valid comment

But we do not rely on gauges PERIOD!!! Thermocouples with a good digital temp meter will DEFINTIELY separate the facts and numbers. I have seen gauges regardless or quality or type be off by as much as 60 degrees, typically at the higher end of the scale. In all honesty the ching chong dime a dozen gauges are sometimes more accurate. Kudo's to BSB67 for reading through the lines of this thread

Was the cruise around town and stop and go? or rolling 40 MPH plus most of the time? My favorite cooling test is 1) run it on the highway fast as possible without gathering attention of a trooper for at least 10 miles and watch it. Does it stabilize at a reasonable temp? 2) Pull off at the next exit and park with engine running. The engine will be good and warm at that point and watch it. Does it stabilize at a reasonable temp? I would consider 210 F OK in that situation, 220 F marginal.

"Middle of the gauge" does not sound bad but you thought it was still climbing? If there is any question about the gauge, an inexpensive mechanical version from the AP store makes a good diagnostic... even if you tape it to your windshield for test.

Yup, going to get a nice mechanical gauge and tape it to the windshield and see what i get!

Good idea on the gauge.

Myself, when it comes to cooling, I have been through this all also. If it were my car, I would:

Confirm temp with a gauge,

Confirm tune

Call Glen Ray and get a factory style radiator built. They will do one without all the date codes etc. so you can save a few bucks there but they are not cheap. Get the right shroud, fan and pulley's . As mentioned, all the places that were sealed from the factory are good to have in place and are designed to make the air flow through the radiator.

If that doesn't do it I would go after the WP housing and run a flow cooler WP.

I run a 496 with the Glenn Ray radiator, factory stuff for the rest other than the flow cooler WP and I ran on the thermostat idling in the staging lanes a couple weeks ago at the track. 90 degree day. I am so sold on this set up that I am using the same thing on the 543 going in my coronet.

Good luck ! Nothing worse than sitting at a light watching the temp creep up, wishing the light would change, the slow driver would speed up, the 18 wheeler could make his left turn faster when you are stuck behind him etc etc.

Ummm, so puller fan helps a lot! :P

Mikey