Technical Cooling issues, need to pick some brains

Here is the shroud.

Looked in cap and don't know how the hell this grit got into this system. Water and additive has been in there for 2 months.

20w50 oil has been tried. Made more oil pressure. But brought temps up 10 degrees

Back to a 10w30 valvoline with zinc additive

No spring in lower rad hose. May be onto something there. Go pro time to watch it I think.

 

Mystery grit is making me wonder how much crap is in that block and whether it was properly tanked the last time it was built. If that is still in there it will hinder heat transfer... if it's moving around it could be plugging your new rad.

 

I got to thinking about my earlier post on what may have changed. I should have included a collapsed lower hose, but I didn't. You found it first. What probably happened was, when you ran it hard, the water pump collapsed the hose at the higher than normal suction and volume. This weakened the hose and now it collapses at the lower cruising rpms. All lower hoses need a spring. Heat your car until it is good and warm and then have an assistant rev the motor to :highway RPMs" and check to see if the hose collapses. Your problem will probably be fixed with a reinforced lower hose. Regarding debris in the coolant. Could be from rust flaking off in the block. I have read of people making a filter to put in the upper hose out of a panty hose. A block flush may be in order also. Good luck.

 

I have had a lot of heating problems in my life most caused by shitty radiators.
I use good quality rads with electric fan(s) and if I don't loose water it ain't to hot.
$.02

 

10 flushes. The right picture is number 5. Right is number 9 and middle 10. Temperature is doing better. Put a spring in lower rad hose as insurance. Those things are getting harder to find.

Flush 1 and number 6 were with flush and cleaner by prestone. I'm amazed I am still getting this color with fresh water flushes.

 

Really has be thinking that the machine shop didn't tank this block long enough?

 

Went for a drive. Fan off at 55 mph rolled up to 210. Now here is the kicker. Get home let it idle in neutral. Drops to 205. Put in gear drops to 200. Why is this not making sense?

So left cooling fan on for 5 min. Temp gauge drops to 185 in 5 min not running. Fire up drops to 165. Let it idle back up to 185 in 3 min.

So coops better under a load in gear than cruise speed or idle. Makes no sense at all.


And when at 185 you can almost hold your hand against the bottom tank for 5 seconds. Top not even a second.

 

You could flush it till the cows come home and not get clean water.

De scaling the inside of a crusty block takes more than soaking or flushing. It takes a good scraping inside, poking into all the water jacket holes you can find. There's sediment chunks of rust and crud built up in the low lying parts of the water jacket.

I did one bare block here with bottle brushes, picks, coat hangers and a garden hose. I turned a 20 X 60 area of black top solid rust orang. Took 2 solid hours of that to get the water to run clean. There were chucks of rust sediment so big they wouldn't fit between the cylinders or out of the freeze plug holes until you managed to break them up. I had never done that before so I was completely amazed at the amount of shit that came out. Who knows it may have been some left over sand from the casting core too.

I recently looked at an engine contemplating purchase that was freshly rebuilt. The block had a long tank session according to the machinist. I broke the engine down for inspection and the scale inside the engine was beyond believable. It looked like the pits of hell and lava rocks wanting to jump off and get you. So I asked the machinest again about his hot tank - well it (his) doesn't remove rust. I said couldn't you have at least poked the big chunks with a screw driver. He didn't want to start loosening the scale. I said yeah that's why you're supposed to get all of it right.
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Ok so it cools better under load, or better than cruise speed or idle. Does it really cool better or is the gauge telling you about the coolant.

The water pump is going slower or at its slowest at those speeds right? The rpms and fires per cylindef are at their slowest also cylinder temps at their lowest. Gauge is telling you about the coolant.

You'll get plenty of opinions here on this that say different but slower water will heat soak more because it has a longer time to do it. A rusty scalely surface isn't going to transfer heat as well either. So if the water needs to navigate scale and deposits how well will it soak heat? How hot is the cylinder walls beneath the scale? Once it hits the heads the heads are probably clear of rust bevause its easy to clean the heads water way and the water pics up some heat on the way out past your temp sender.

A radiator with a hot top tank and cool lower tank are the absolute holy grail where cooling is concerned.

 

Fill it with white vinegar for a few days. You can drive it, relax. When you flush, you probably should remove the rad and flush from both directions cause it will probably be full of crud and flakes. The block should be clean and look like fresh cast. If not repeat with clean white vinegar until clean.

Then you can start testing other stuff. Be careful, this can crud your rad up pretty quick if you have a very bad rusty or scaly block. Keep an eye on it

 

Have you tried Water Wetter or similar product?

 

Has water wetter in there now. I replaced it on my last flush.

Thinking of picking up either a laser thermometer or a bore scope now.

Slept on it and trying to figure it out. May change thermostat back to cheap stant today.

 

ok. Laser thermometer show 195 at top of core. 170 to 178 at bottom of core at idle with fan on high and temp gauge showing 195. Exhaust temps at idle are I higher than I thought . 585 f across the board. So is a 20 degree temp difference enough?

Maybe my radiator is too small ? Or is the high flow water pump just creating more of an issue.

This was on a 15 minute trip but I did let it warm up in driveway before heading out.

 

I think your hi flow water pump may be your problem. It is not letting the water stay in the radiator long enough to get cool. That is why it is semi cool at idle and hot running down the road.

 

Contrary to popular opinion, try installing a thermostat without drilling the 1/8 hole in it.

 

Just a thought,is your water pump pulley the same size as your crank pulley? HRP

 

Thermostat in there has no holes drilled an same size pulley

 

A small water pump pulley will do a better job of circulating the water HRP

 

It is possible, maybe not likely, that your hard running affected your fan belts/pulleys. An old timer trick is to start the engine and dress both sides of the fan belts with beeswax. (Dangerous and I am not recommending this.)A safer method would be to get new belts. A second thing to check is the condition of the pulleys. Get a fat tipped magic marker and coat the sides and bottoms of all pulleys. Run the motor and see where the marker has been worn off. Only the sides of the pulley grooves should be cleaned off. If the bottom of the pulleys are shiney, the belts are running on the bottom. This means wrong/worn belts or pulleys. I know this is a long shot, but you seem to have tried just about everything else. It will really be interesting to know the cause of your cooling issues. Thank you for your feedback on what you have done.

 

If it ain't puking coolant, it is not overheating.

The originally posted temperature numbers, while a few degrees high, wouldn't alarm me.

Several of my vehicles run there, factory stock, except the wife's diesel.

 

Here's what happened to me with my '52 Chevy. It came with a sbc that the builder said would overheat on the freeway. The fan pulled great air through the radiator, so I had it "rotted out" at a local radiator shop. My first cruise, it ran at 180 until I hit a toll booth. The temp climbed to 210 and stayed there. So I went with a new triple pass radiator and a high flow 160 thermostat. She ran at 160 until I went up a steep hill. By the time I hit the top, it was 210 again, but cooled right down on the downhill. This was frustrating as I wanted to add A/C. Checked the timing and the advance was frozen in full retard. Swapped distributors and now she runs at 140, 180 with the A/C on with it's 90+ outside.

 

After a lot of thinking I have come up with an idea. I don't think water flow is really my issue. I'm thinking the rad just isn't efficient enough to cool correctly. 15 degree drop and motor is putting a few extra degrees every time fluid passes through. Rad gets to a point where outside ambient temp of 95 degrees is doing its job vs what the motor is putting out. Heat exchange on 205 degrees vs 95 outside air is steeper drop than 180 degrees vs 95 air. Driving it and when I get to 60 and shut off fans it stabilizes at 205 to 202 not terrible but still cautious of getting on big road for extended time.

Old water pump I had was slower flow rates allowing more heat to strip at radiator vs higher flow. Decent at cruise speed for a bit then superheating starts I think.

Am I in the ball park for my thoughts here?

Should I do a external oil cooler to help engine out more ?

10 degrees outside air temp increase is leading to 10 degree coolant temp increase from 80s to the 90s area

So if I do decide to ditch this 3 row champion for a 4 row walker or brass works. Single or Tripple pass ? And do you think they are worth the money ? My buddies 29 has a walker and runs 180 cruising and creeps to 200 in stop and go traffic.

 

Again, thicker core means harder for air to pass through, so may do nothing to alleviate cooling issues. Sure, the larger quantity of water will forestall overheating a bit, but if flow is an issue (it was for me), you will still have overheating. As Gimpy has said, those temps are not high, and you have not indicated any boiling. Therefore, you may be making up a problem where none really exists.

Cosmo

 

Have you looked at timing? hard running may have moved distributor. Also check centrifugal and vacuum advance motion.

 

Looked at timing, its advancing as it should.

A walker 4 core is only 1/4" to 3/8" more than where I am at now. but the top tank capacity is about double.

Thermostats don't fully open till 20 degrees above their rated temp, And I am settling in about 205 area, Maybe a 160 will help?

Factory OE thermostat on the BB mopar is 195. That seems high for some reason.

I know the temps are not high, I have seen worse, But the freeways around this area are not the easiest to get off once you get on and with all the construction you better have it set right and commit when getting on the big roads. To hit back country roads its an hour drive no matter what.

May have to just pack a cooler, sunscreen and take out at 6am one sunday morning, drive somewhere, about noon head home and see if the cooling system holds up.

 

this tells me the collant is moving to fast rpm drops to an idle it removes more heat more rpm drop in gear removes more heat i would put a 195 or 205 thermostat in it and a smaller crank pulley to slow things down some

 

check your temp gauge. I have one that is spot on at 180 and 190 after that it shows 200 210 and with a lazer temp gauge it show max 190 at the top of the radiator

 

My 383 had a similar problem and I found it had air in the system that wouldn't bleed out. Temp gauge didn't read correctly and temp didn't make sense. Drilled holes in stat, loosened hose fittings to purge air, and it corrected itself. Had to add another gallon of fluid.

 

An old wives tale that the water can't do the job if it's moving too fast, probably coming from people discarding the thermostat and suffering even worse overheating.

Yes, removing a thermostat can indeed create overheating problems, but because the thermostat is a restriction for the water coming out of the engine, i.e. it increases the water pressure inside the engine (even when fully open, since it's smaller than the hoses etc.). Simple physics, higher pressure increases the boiling point of water.

If the cooling system can barely keep up when the thermostat is in place, removing it might be the straw that breaks the camels back - dropping the pressure and boiling point inside the engine, letting coolant boil, steam pockets form, hotspots getting larger as coolant is kept away from metal by the steam bubbles, and by then you might be looking for another engine...

Note: I'm not saying anything specific about the engine or waterpump the thread is about, just that fast moving water being unable to cool an engine is a myth.

 

Fast moving like a river is not the same as moving too quickly between the engine and the radiator and back to the engine. There's 2 parts to the cooling/heating problem and each need equal focus. If you do desire to move the water quickly, the radiator must be efficient enough to drop the temp enough for the shorter amount of time the water will be in it. That radiator is set to shed so many BTUs of heat per hour. A math wizard can figure exactly how many BTU it will shed in 10 seconds vs 20 vs 30 seconds but common sense will tell you it's going to shed 2x more at 20 and 3x more at 30. The thermostat being normally closed until set temp keeps the water from leaving the radiator for a few extra BTUs to leave.

If the rate of heat production surpasses the rate of heat reduction it will over heat. Heat transfer is what keeps overheating at bay. Shedding the heat generated from the coolants collecting of heat seems to be more important than collecting. Some focus on the collecting, some focus on shedding but neither one can work without the other.

Thermostats facilitate reaching operating temp faster and then maintains that temperature. If by chance the thermostat reaches a state where its Wide open and not soon returning to operating as a thermal valve by opening and closing, the overheating moment is at hand in the near future. When the thermostat reaches that wide open state the coolant is transferring from the engine to the radiator and back as fast as it ever will, ie coolant moving faster doesn't seem to be increasing the cooling capacity of the system because it overheats.

 

If you think it's an old wives tale, try moving your finger through a candle flame at progressively slower speeds to see if it affects heat transfer.