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440 Running Warm - Why

restriction, too much air in the system, or the most over looked item .... radiator cap ! If there was a restriction you'd definitely be running hot at idle though.
Yep, exactly - and wouldn't trapped air have been addressed after the thermostat opened?
I could see that being a problem if the top of the radiator was actually lower than the thermostat housing on the engine, but...
 
Here's a thought. Get yourself an IR temp sensor and check the temp at inlet and outlet of the radiator. I wonder what the temp drop is from top tank to bottom tank.
 
There are actually videos on YT right now of 440s on dynos sucking the lower hose collapsed; been there seen that, even on my own car.
I made a spring for it just for peace of mind, after having zero luck finding one online (other than from that wonky Mustang parts supplier).
I know I'm way late in the game but for what its worth I asked the "Old man" about this (radiator hose spring/coil) and he reaffirmed what I had researched after. He basically said when the cooling system of a car is completely drained, or in the case of a brand new car under construction, never had coolant in it, there is a considerable amount of air in the passage ways. Normally, when filling up the cooling system, you start the car to circulate the coolant, displace trapped air, and then top it off.

On the assembly line, this wasn't feasible, so air in the cooling system was evacuated by essentially pulling a vacuum on it. This also had the added advantage of speeding up the introduction of the coolant mixture to the cooling system as well. The coil in the lower radiator hose prevented the hose from collapsing under this higher than normal vacuum.

Once the car left the factory, the coil served no further purpose. This is why replacement hoses usually do not have a coil in them.

This may be old knowledge but thought I'd share on this older post :)
 
New to the forum and had never seen this thread before either. Some interesting thoughts posted.
If you have a collapsed hose on a hot engine you have more wrong than the hose. Only time you ever saw a collapsed hoses was on a cold engine, caused by a bad rad cap. Caps have two separate venting valves. One allows expanding air pressure above the caps pressure design to vent off. With that air vented, when the engine cools it has to draw air back in. If this suction vent is stuck the shrinking contents of the cooling system puts it into a vacuum and the hoses collapse.

Another interesting point is that most times an engine with marginal cooling capacity will actually run hotter with the stat removed. The stat, even when fully opened, puts a restriction in the circuit, which slows the flow through the rad. Coolant flowing too quickly through the rad won't loose an adequate amount of heat.

Doesn't happen often, but water pumps should be checked for corroded impeller. I've seen pumps where the impeller was corroded down to almost half it's original size. And it's not just about the size, it's about the clearance between impeller and body that changed.

Which is a good lead in to the next thing that should be considered. I have seen many, and I do mean a lot, of engine blocks filled with rust paste to well above the frost plugs. I don't know if I still have them, but I took pics of one where I scooped it out with a kitchen spoon. This is not something that you are ever going to flush out. It's why the sell brass frost plugs. Can't get rid of the rust and steel plugs barely last a year. In this 383 I'm working on at the moment I probably spent a half hour with our 11 hp steam pressure washer before it started to run clear. That's with the engine on the ground and rolling it over every which way shooting through the frost plug holes to get at the knooks and cranny's. Initially it's just blobs of gunk.
 
Again, all I can tell you is what I've experienced myself - and it doesn't take a lot of research time online to see these hoses being collapsed, either. I even watched a dyno video recently of a big block sucking one shut on a pull.
These hoses used to come with a coil in them, both from Ma Mopar as well as aftermarket replacements.
There was a reason for that.
Besides, there's no harm in having one, even if it is what some say is a waste.
I've got one in mine now. One less thing to possibly go wrong.
 
You saw what you saw, but I'd sure like to know the science behind it. It's a puzzler for sure. Pressure in a closed cooling system is equal everywhere. The pressure in the system is the result of expansion, nothing to do with the pump. Those centrifugal pumps don't make enough suction or pressure to move a needle on a gauge, never mind collapse a hose (pull the supply side heater hose and put your finger over the end).

In thinking about it further, I suspect that the engine on a dyno is not connected to a closed system with a rad, but rather to a system with it's own pump. Might have something to do with that.

I always thought the springs were in there to prevent kinking on a bend.
 
You saw what you saw, but I'd sure like to know the science behind it. It's a puzzler for sure. Pressure in a closed cooling system is equal everywhere. The pressure in the system is the result of expansion, nothing to do with the pump. Those centrifugal pumps don't make enough suction or pressure to move a needle on a gauge, never mind collapse a hose (pull the supply side heater hose and put your finger over the end).

In thinking about it further, I suspect that the engine on a dyno is not connected to a closed system with a rad, but rather to a system with it's own pump. Might have something to do with that.

I always thought the springs were in there to prevent kinking on a bend.
Well, pumps are doing something, after all - namely, circulating coolant.
They have a suction and a discharge side as a result - all pumps do.
(Part of my trade for the last 35+ years - fire pumps)
Suction is read in psi, as is discharge pressure - because the pump does indeed generate pressure, both positive and negative.
Yes, the bottom hoses on our big blocks are the suction side of the pump.

Another aspect of this subject that hasn't really been discussed is the quality of the hoses being made today. I submit, again my opinion, that they aren't as stout as they used to be and that they may not even be made of the same chemical composition as say 30 years ago.
When I contacted a couple of the manufacturers' engineering departments about this subject (why they don't use springs anymore), the consensus was that they claimed todays' hoses are made of better quality materials and that the old school hoses' biggest failing point usually was a separation of the inner lining from the outer, hence the need for a spring.
Their claim is that this cannot happen with modern constructed hoses because of how they're made and what they're made of.
I dunno, sure is easy for me to take a new one and collapse it in my hand....

Yes, a moderate to sharp bend in a hose is a natural place for a kink/collapse to occur, so springs helped with that no doubt.

Final point from me on this subject:
If springs aren't needed in hoses anymore, then why are most of those universal type hoses constructed with a heavy outer spiral (many with actual steel springs impregnated in the poly/rubber itself)?
So they won't collapse as you contort them into the desired position, that's why.
 
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The part about the internal lining separating makes sense...I do know that when my car is up to operating temp, those hoses are pretty rock solid from the internal pressure expansion
 
I hope no one is taking any offence in continuing the discussion.

In order for a hose to collapse the inside pressure has to be lower than outside pressure (atmospheric). You have a cooling system under 15 psi at the rad cap (rad cap spec). Now somehow you have to get that pressure down to below 0 psi at the bottom of the rad in order for the lower hose to collapse. To get a pressure drop of 15 psi between the top of the rad and the bottom you'd have to have a huge restriction in the rad and/or an enormous suction capacity.

There must be a pressure differential for coolant to circulate. But with these pumps, you wouldn't be able to lift a 0-10 psi gauge off the pin on the outlet side and you won't be able to pull a readable vacuum on the suction side. I would liken them to a spoon stirring a pot of water. The pressure ahead of the spoon is greater than behind it, so the water moves. These pumps don't do much more than that. You could take a heater hose off and put a gauge in it (rad cap off) to confirm this.

The lower hose only forms part of the suction side. Pump intake is divided between the rad and the block, so that coolant circulates even when the rad can't flow anything (t-stat closed). So you won't pull much vacuum if it can draw elsewhere.

As for the hoses, they don't have to be hard, the system pressure inflates them and holds them rigid. I don't know about the inner lining failing. Yes it happens, but it would seem to me that it would be cheaper to make a better hose than have to supply a spring to keep the inner material from dislodging. My money would still be on them being there to keep from kinking when bending them, just like the universal flex hoses.

I've had a little experience with this kind of stuff myself. This next spring marks 40 years with my Automotive Journeyman's ticket. Four year apprenticeship and a few years working on this stuff before I started my training on top of that, so I'm getting dangerously close to 50 years playing. This was the stuff I cut my teeth on. The last 12 years I've worked with Ag equipment, so in addition to AC and cooling systems, we do a lot with other pumps. Mostly positive displacement hydraulics, but lots of centrifugal pumps as well.

Still having fun though.
 
I put in a 195 degree thermostat as per the factory specifications, car now runs at 195 degrees, but does take a while to warm up to 195 degrees when riding around town. Warms right up on the interstate.

Thank you to all for your help.
 
69 Roadrunner, 73 440 6-pack, not factory cam. I noticed the thermostat housing was leaking. Went and got a gasket and thought I'd replace the thermostat along with it (not knowing how old it was). Auto parts store only had two (2) 160 degrees and 180 degrees. Got the lower one. When I pulled the housing off, out popped a 195 degree thermostat. I figured; black car, only plan on driving in the good months, not needing the heater, I put the 160 in hoping the engine would run a little cooler. An after thought, I checked the manual and it calls for 190. Is that just to get heat from the heater? Will running a 160 hurt the motor? Would there be performance issues?
 
Too cold of an engine is detrimental to it. It can wash the cylinders, oil doesn’t get hot enough to burn off the acids/condensation and basically makes the engine not run as it should. Stuck either a 180 or 190 in it, your engine will thank you.
 
Read somewhere on here that 190 is better for the six pack intake.
 
I have had a 160 in my six pack car for over 25 years with no issues. Runs about 180 around town and will get up to 210 in bumper to bumper Woodward type traffic. How does a 190 help a sixpack car over any other 4 barrel car.
 
Had the same problem in my big block Dart. Was running a aftermarket water pump. Pushed a lot of coolant. My problem was I was running a cheap T stat. Around town, at the lowerRPMS and idle it worked great, kept the temps down. On the freeway the pump was pushing coolant passed the capability of the T stat. Add to that it wasn’t opening all the way. Installed a high flow stat, problem solved.
 
69 Roadrunner, 73 440 6-pack, not factory cam. I noticed the thermostat housing was leaking. Went and got a gasket and thought I'd replace the thermostat along with it (not knowing how old it was). Auto parts store only had two (2) 160 degrees and 180 degrees. Got the lower one. When I pulled the housing off, out popped a 195 degree thermostat. I figured; black car, only plan on driving in the good months, not needing the heater, I put the 160 in hoping the engine would run a little cooler. An after thought, I checked the manual and it calls for 190. Is that just to get heat from the heater? Will running a 160 hurt the motor? Would there be performance issues?
Factory calls for a 190-195 thermostat on a 6 pack engine. Motor has to be warm enough to swallow that gas,for years I ran my Bee back in the day with no thermostat but that isn't recommended,now in my 69Dart I run a 195 thermostat my motor runs at that temp a little bit more on hot days 200 but in traffic it sux I'm in the process of swapping out my factory 26" Radiator for a two row cold case I'll post my results when the time comes
 
for years I ran my Bee back in the day with no thermostat
Go figure. I got smart (?) the other day, got one of those 180 Superstats, and dropped it into place. Short test run, five miles each way, and back to check temps. Both on the gauge, and the temp gun, engine was hot as a firecracker! Hotter than it's been, since I've gotten it to run. And, yeah, tested the stat...it opens.
Any rate, no thermostat in mine, now. 440s are hot natured anyway, then toss in Texas heat...yeah.
 
I'm with ya on that so now how is it running with the stat out 180*?
 
how is it running with the stat out 180*?
Haven't had a chance to do much of a test run, but short drive looks good. Dang Texas heat don't help. But, did check flow, and it's decent. 64 SF, using a 22" 3 core rad out of a 67, with the two piece metal shroud. Air flow with the fixed fan, at idle, pulls a sheet of paper against the core. We'll see...

Really surprised me, how it did with that stat in. 440 dang near cooked.
 
A 160 stat doesn't leave the coolant in the radiator long enough( so i'm told). 180 works good.
 
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