"Charlie" has Overheating probs- Here are my Clues and please chime in with opinions!

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Keep hacking at the crap in the block, and back flushing. Keep an eye on the radiator for trying to clog.
 
. . .thinking of separating the engine block from the radiator and isolating it so I can pour something like varsol or even diesel (Kerosene perhaps?) into the core of the engine. That stuff I got out was like black carbon and obviously had no water percolate into it in spite of running it regularly for over 8 months. Let it set, flush it out and see what gets dissolved into the fluid. . .what does long dried antifreeze turn into?

. . .another thing that is on my mind is, it ran cool for the 8 months from 1 Oct. '09 to May '10, racking up some long highway runs and in some weather that was into the nineties. . . then, suddenly, it won't cool. I can't see a thing inside my radiator, it looks clean- but the tubes are so darned narrow that I can't shine light down them to see if a big batch of rust was just vomited into the tubes and partially blocked them. Anybody know how I could shine light through them, rod them, test them with high pressure water or air to see if they caught a big dose of crap? It is an all aluminum radiator too- which makes taking it apart tougher.

Unable to work on it right now, but will get back to it this Sunday hopefully.

Mike
 
is it a verticle core or cross flow? using a garden hose with the hoses off should tell you if its clogged if it doest back up with full volume from the hose, its probably fine. i had the exact same thing going on with my duster. one day i drove it for 3 hrs on the highway in the dead of summer and all of a sudden the temp started climbing at night while it was cooler. made no sense to me. that black funk sitting at the bottom of the block would start to loosen i guess with the higher flow of water at highway speed it would then restrict the flow in the rad enough to make the temp creep up yet would idle or low speed drive, with no issues. i did the panty hose trick on the upper hose for a while it sure did catch a ton of crap.
 
they dont get enough air on the radiator
you will notice that your problem becomes worse after a highway cruise and then slow/stop and go traffic, the temp guage keeps getting higher with slower speed
with a 50 to 1 air to coolant ratio, there is not enough air passing through the radiator core to transmit the heat.
shroud the radiator fan and increase the fan blade count, also , make sure your lower radiator hose is not collapsing under suction load

hope this helps
 
they dont get enough air on the radiator
you will notice that your problem becomes worse after a highway cruise and then slow/stop and go traffic, the temp guage keeps getting higher with slower speed
with a 50 to 1 air to coolant ratio, there is not enough air passing through the radiator core to transmit the heat.
shroud the radiator fan and increase the fan blade count, also , make sure your lower radiator hose is not collapsing under suction load

hope this helps
X1 Also you can go with an Electric fan and thermostat setup.
Frank
 
they dont get enough air on the radiator
you will notice that your problem becomes worse after a highway cruise and then slow/stop and go traffic, the temp guage keeps getting higher with slower speed
with a 50 to 1 air to coolant ratio, there is not enough air passing through the radiator core to transmit the heat.
shroud the radiator fan and increase the fan blade count, also , make sure your lower radiator hose is not collapsing under suction load

hope this helps

I tried telling him this by asking if he still had that factory pos fan, which he does....

but no reply.

people skip the most obvious sht sometimes, I mean..a 4 bladed fan???? come on????
and no shroud???
 
is it a verticle core or cross flow? using a garden hose with the hoses off should tell you if its clogged if it doest back up with full volume from the hose, its probably fine. i had the exact same thing going on with my duster. one day i drove it for 3 hrs on the highway in the dead of summer and all of a sudden the temp started climbing at night while it was cooler. made no sense to me. that black funk sitting at the bottom of the block would start to loosen i guess with the higher flow of water at highway speed it would then restrict the flow in the rad enough to make the temp creep up yet would idle or low speed drive, with no issues. i did the panty hose trick on the upper hose for a while it sure did catch a ton of crap.

Vertical flow, James. And, I am still leaning toward it being partially clogged and slowing down the flow through the tubes. I get ya on the flow test too- I'll try that; if it will flow that much volume it probably isn't too full of stuff.
 
they dont get enough air on the radiator
you will notice that your problem becomes worse after a highway cruise and then slow/stop and go traffic, the temp guage keeps getting higher with slower speed
with a 50 to 1 air to coolant ratio, there is not enough air passing through the radiator core to transmit the heat.
shroud the radiator fan and increase the fan blade count, also , make sure your lower radiator hose is not collapsing under suction load

hope this helps
Thanks Bill.

The lower hose did look like it was collapsing, so I replaced it with one that has the internal spring to hold it open. The fact it was collapsing any might mean it has a problem pulling water out of the radiator (clog) or, it was too pliable.
 
I tried telling him this by asking if he still had that factory pos fan, which he does....

but no reply.

people skip the most obvious sht sometimes, I mean..a 4 bladed fan???? come on????
and no shroud???


You are correct in pointing out that I can and will make a simple problem and solution more complex than it is- I do think too much.

Your reply: I do not want to put a large, multi-bladed electric fan on this car unless absolutely necessary. And, it shouldn't be necessary.

What I am trying to do- and what everyone has been giving me help and advice on here (again thanks for all that have expressed an interest), is to make the darned car work as it was originally designed to do.

Feller, all I am is a pilot by trade- all the training that I have for auto repair comes from some native curiosity and a lot of self study.

It also helps in this case that I have literally been driving a 1967 Plymouth Barracuda for 41 years and 314 k miles.

Ma Mopar engineered enough air gaps in the front of the car to adequately channel enough air for cooling through the radiator- and nothing has been changed about that.

Ma also designed and installed "just enough" radiator, shroud, fan, pump, etc. into the cooling system to make it reliably cool in all seasons and driving conditions. Me, I have seen my bone stocker get hot sitting still in traffic with the A/C on, so I modified it to turn off the compressor while keeping the fan working inside. . .I never had it get hot on the freeway unless I blew a hose or something. That one was a smallblock v-8. The only other things I did over the years was a flexfan and took off the shroud- it was busted anyway.

In my opinion, and Only my opinion, the fan and shroud is a good implement to have if you are sitting at a light with no wind of motion through your radiator. There may be some improvements in forcing flow thorough more parts of the cooling fins with a shroud while sitting still, but it is not necessarily crucial unless you are making a heck of a lot of heat in your motor. Perhaps a big block makes more heat than a smallblock- or a slant six and needs those cooling aids quicker. I just always found that my cars would warm up while sitting and cool off while moving- and I would just make sure I didn't sit so long that they would get hot.

This is a second '67 I picked up last year (see posts and pics). I got her working reliably. . . and now relatively suddenly, she isn't. Something about that slant six changed so that now it is putting more calories (heat) into that water jacket and overpowering the cooling system- one that has been improved already by a much larger capacity radiator. It isn't overheating quickly either at idle or at speed- but it does overheat eventually, and no combination of speed and power usage stops it once it gets past the halfway mark. So, either the motor is putting out a bunch more heat than designed suddenly- or my cooling system has been compromised somehow.

You guys and gals are helping me track down what changed. It is a mechanical contrivance, engineered to work reliably. It should be fixable with just the gear it came with.

The other mods I can and will hang on my other one when it comes back out of body and paint- but I will be doing so to lose performance robbing hardware off the engine, not because the thing will need that gear to run at proper operating temperature.

Again, appreciate the insights from all of you.
 
Ma Mopar engineered enough air gaps in the front of the car to adequately channel enough air for cooling through the radiator- and nothing has been changed about that.

Ma also designed and installed "just enough" radiator, shroud, fan, pump, etc. into the cooling system to make it reliably cool in all seasons and driving conditions. Me, I have seen my bone stocker get hot sitting still in traffic with the A/C on, so I modified it to turn off the compressor while keeping the fan working inside. . .I never had it get hot on the freeway unless I blew a hose or something. That one was a smallblock v-8. The only other things I did over the years was a flexfan and took off the shroud- it was busted anyway.



QUOTE]

being a pilot , you have obviously seen over heating due to air 'stall' in the engine compartment, all this air collected must go somewhere, usually under the car and out the fenderwells, make sure the air can cleanly remove itself after it collects the heat from the engine compartment
You spoke of a flooding condition on hot starts, that may mean you have some methenal in your fuel and its boiling in the carb with the engine off and high under hood temps
An electric fan wired to run with the thermo switch on and the key off can be a good addition to clear up your problem
 
Lower radiator hose collapsing at speed? The ones with the spring inside are better.
 
i always wondered about using something like evaporust in a cooling system, then a guy on another site brought it up, he said flush the system till its pretty clean, drain it, put 2 gallons of evapo rust in, run it till it gets warm, let it sit a day or 2. drain the system collecting the evaporust, then pour it through a filert cloth to catch the particles and you can reuse the evaporust. im not sure if he actually did it, but it would probably bebest to do it with no thermostat and no cap. you can buy it by the gallons or 5 gallons under other names. similar product. non toxic and only attacks rust. doesnt harm paint, other metals or rubber and plastic. so they say.
 
i always wondered about using something like evaporust in a cooling system, then a guy on another site brought it up, he said flush the system till its pretty clean, drain it, put 2 gallons of evapo rust in, run it till it gets warm, let it sit a day or 2. drain the system collecting the evaporust, then pour it through a filert cloth to catch the particles and you can reuse the evaporust. im not sure if he actually did it, but it would probably bebest to do it with no thermostat and no cap. you can buy it by the gallons or 5 gallons under other names. similar product. non toxic and only attacks rust. doesnt harm paint, other metals or rubber and plastic. so they say.

I use worlds Safest Rust Remover and swear by it for redoing a cooling system. I have run it for a couple of weeks on a really bad engine. I run a 4 to 1 solution.
Frank
 
Jame, Frank- a very nice idea! I like both and will investigate further.

Back from the road, where I have been contemplating the bad girl's engine overheating while I had nothing else to do but think.

I will, in no particular order investigate: is it really timed right? Will use a TDC technique TopHat from SlantSix.org recommended to see if the TDC mark is accurate- and see if it is really, really set advanced or retarded. If retarded and once reset advanced, will I manage to get the fool thing to run without what appears to be spark scatter and a miss under a load? Will that finally "fix" this pesky overheating problem too?

I will check to see if I can see light thorough the tubes of the radiator to see if it is choked. I think I can probably use a glowstick on a string shoved into the bottom inlet. . .and perhaps a dentist's mirror on the top side to catch any glow. . .in a dark garage. . .

As a nod to Bill H., CrazyGuy, and InkJunkie, I will indeed see if that v-8 sized, aftermarket 3 core radiator is acting as an air dam instead of letting air through at speed. Shroud? Doubt I can find one that fits the thing for an engine-driven fan- but an aftermarket, thermostat activated electric fan usually comes with its own shroud. I am still not crazy with the idea that a v-8 radiator won't cool a slant without such help- but perhaps such is the case here.

Also from TopHat and James- will probably pop out the freeze plugs and see what I can see inside. Dig as necessary. That and the Evaporust or equivalent poured inside for a day or two might just do the trick.

Will let all of you know how it comes out as I proceed. Appreciate all the good ideas and places to look gentlemen.

Mike
 
I knocked out rear freeze plugs and removed chunks of crap half the size of golf balls.
Between the rust sediment and stop leak products poured in the radiater by the previous owner ( annually since engine rebuild in 1984 ) its no wonder it ran a little hot.
I had the radiater properly repaired and replaced the 7 lb. weak system cap with a proper one.
Problem solved. OEM 4 blade fan, no shroud.
 
After you seen the black "gunk" in the cooling system, you should have done the right thing and rebuild it. Stop putting a band-ade on it.
 
Not the TDC mark- my calculations make the timing all of 2 degrees different- and advanced- from the original slot.

Where and how many freeze plugs? Two big ones on the driver's side. . .any between the back of the block and the tranny?

Thanks Redfish.
 
After you seen the black "gunk" in the cooling system, you should have done the right thing and rebuild it. Stop putting a band-ade on it.

Trying not to put a Band-Aid on it, if I can- but that may well be the direction I may have to go. Just hate having to do that if not necessary- and putting the car down for an indeterminate time while I tear it down and have it hot tanked. Not to mention the money I have set aside for the other project getting sucked into this one. . .

Don't ya just Love the discovery of former owner ignorance and neglect? Makes me want to drop the slant through his roof :)
 
i think the black gunk is the issue and i really dont think that it needs a tear down to be taken care of.
 
Not the TDC mark- my calculations make the timing all of 2 degrees different- and advanced- from the original slot.

Where and how many freeze plugs? Two big ones on the driver's side. . .any between the back of the block and the tranny?

Thanks Redfish.

Rear plug on left and right side. I had a garden hose and spray nozzle under there too.
 
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