I now have two spare 93/94 copper/brass rads!

Discussion in '80-Series Tech' started by IdahoDoug, Jun 17, 2005.

  1. IdahoDoug

    IdahoDoug

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    I have my brother in law's 287k rad that's weeping badly out of the top and bottom seams, and now I have another due to a funny coincidence yesterday.

    I stopped at the best rad shop in town yesterday to see what they'd charge me to clean the core and replace the upper and lower O rings in my bro in law's old one so I could keep a healthy one on hand for spares or the Cruiser Assistance Club. Parked out front and walked up to the counter. As I did, the guy behind the counter pointed at a large Toyota box on the corner and said "There's your radiator, sir." Out of curiosity, I pushed a flap aside and there was a brand new 93/4 copper/brass radiator - OEM! "It's not mine, but I'd be glad to take it off your hands seeing how it's in the way out here." He looked out the window and said "You're here for a 94 LandCruiser radiator, aren't you?"

    Turns out by utter coincidence they had ordered an OEM rad to install in an Emerald Green 94 and they thought I was the guy. Too funny. So I asked how much they'd charge to rebuild my old one, etc then asked if the owner didn't want it if I could come back tomorrow and pick this old one up as a spare.

    So, today I picked it up. It's got 106k on it and is in perfect shape save for the usual weep at the top tank. Small world.

    DougM
     
  2. Rich

    Rich

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    What you would really want to find out is if the shop can source new high quality replacement tanks. A new o ring will solve the leaking, but only a new tank would reduce the likelyhood of the plastic itself failing.

    Did they say if they have the equipment to recrimp the tanks?
     
  3. IdahoDoug

    IdahoDoug

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    I think by the time you put new top and bottom tanks on as well as O rings you're just too close to a new OEM from Cdan to bother.

    This is my theory - no data to back me up - but I believe the plastic tanks are fine and plenty able to run the life of the truck. What kills them are mechanics leaning heavily on the plastic top tank and cracking them as well as overcompressing the O ring and seam. It is near impossible to get up on the engine for rear heater hoses, rear sparkplug changes, etc without wanting to put a knee on that thing. I'm not defending the design as I'd rather the truck were two pounds heavier and had metal rad tanks. It's just the size of the 80's engine bay and an engine longer than a V12 that make it difficult to work around that plastic tank. I base this partly on the fact that the top and bottom tanks use the exact same design, yet it's always the top one that has problems cracking.

    The shop said they don't have the little press to recrimp the tanks. They, like other high volume rad shops, routinely work on plastic tanked radiators and have done this before for a variety of brands. They report that the crimping fingers tend to break, so they often buy that part along with the O rings. They use a screwdriver with a tip bent 90 degrees and have no problems. This jibes with my thinking that the whole operation is really not rocket science - just time consuming and requiring a little sensitivity in the fingers to evenly tension the little metal tabs.

    I do not have data on another contention of mine regarding the "exploding" top tanks, but suspect that these units were allowed to get low on coolant, then boiled which dramatically increases pressure. Nobody likes to admit they let a rad get low on coolant, but the coolant pressure isn't much on a hot engine if it's full - ya gotta let things boil to do that and that means air in the rad.

    DougM
     
  4. cruiserdan

    cruiserdan SupportingVendor Emeritus Moderator

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    Replacement tanks, o-rings and clamping bands are available as replacement parts. By the time you buy a top tank, an o-ring and two clamping bads you are well on the way to the cost of a complete radiator.
     
  5. RavenTai

    RavenTai

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    Doug could you pull a fin section out of one of those take the paint off and post a pic?
     
  6. IdahoDoug

    IdahoDoug

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    Raven,

    Actually, I'm not going to destroy them - I'm thinking of buying an O-ring set from Dan and trying to make them serviceable again. If I read you, you're interested in the internal structure and when I pull them apart (which I guess I could do Sunday if it's rainy) I'll be able to take a picture of the entire core structure and a closeup of a piece. Is that what you're interested in - Cruiser porn?

    DougM
     
  7. RavenTai

    RavenTai

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    Sorry I was not clear,

    I would not ask you make a possibly usable cruiser part into an unusable part, as you said either of those rads could save your bacon or someone in the CAC,

    I am wondering if the fins on the brass radiator are actually copper. I have a hunch that I have not yet been able confirm on my own, more interested in one of the fins between the tubes (the part that does not carry water, only heat) One single fin from a corner out of the radiator could not hurt?, I assume you could get one fin out with a pair of dikes without damaging anything else or creating a leak?

    Any info about the tubes material is quite welcome also. From what I have read I think the tubes are going to be brass but no confirmation. And yes I’ll take any cruiser porn I can get my dirty paws on, a pic of the tubes/cores with the tanks off could be cool.

    Any alternative method to determine the materials used in the construction of the brass radiator without removing a fin would be great also. Maybe you can scrape some paint and get an eyeball on the materials without removing any pieces. A little rattle can black and good as new.

    It would not make sense from a performance standpoint for Toyota to use all brass when copper fins could noticeably improve its efficiency, several have the belief that the early radiator has better cooling ability, it is also cheaper, this makes it an easy choice when choosing a new radiator, the price is easy enough to confirm, the cooling ability is debatable until somebody gets us some solid info, actual material it is made of would be a step in that direction, comparison of construction, fin density, surface area, depth etc might be another.

    When looking at the 96 NCF it states the aluminum radiator was selected to save weight, says nothing about improved cooling. CDan has said similar.

    You can tell the difference between copper and brass by eye with high confidence, but unfortunately if another copper based alloy was possibly used (different brasses and bronzes) visual inspection gets less conclusive.
     
    Last edited: Jun 18, 2005
  8. IdahoDoug

    IdahoDoug

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    I'll pull it apart Sunday and post photos. I've been wondering the same. I voted with my wallet for a new 93/4 version when I replaced the one in the 97 - would have paid more for it actually. Aluminum is brittle, and cannot be repaired, plus I believe copper transfers heat considerably better. Wonder if the black paint they put on the fins actually slows heat transfer? Seems like it would, but perhaps the patina it would otherwise get would also slow the heat transfer from metal to surrounding/passing air.

    DougM
     
  9. IdahoDoug

    IdahoDoug

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    I was just thinking if anyone's got a 95-97 aluminum radiator around it would make an interesting long distance static test comparison. Heat a gallon or so of water to 200 degrees on a day that the air is 75 degrees, fill the radiator to the top, wait 30 minutes and stick an oven thermometer in the neck. Whichever sheds heat quickest is the heat transfer winner assuming both are in similar states of internal deposits. Since I have two and it's easy to see the 106k one is way more clogged, I could actually tell if clogging would affect static heat shedding. My guess is minimally, actually as the clogging's gonna affect moving water cooling far more greatly.

    The more I think about it, the more this would provide accurate data that would effectively isolate the radiator fin's heat shedding ability unto itself. This SHOULD be an effective measure of their cooling ability in operation as well, though there are a couple things clouding that theory. I'll start a post if nobody here can get their hands on a 95-97 aluminum radiator.

    DougM
     
  10. Rich

    Rich

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    Aluminum radiators can be repaired with the appropriate brazing materials.

    Black coating enhances transfer of heat.

    My understanding is that copper radiates heat better than aluminum. And that aluminum radiates heat better than solder coated copper (as what you have in a copper radiator).

    Here's an interesting video: http://www.muggyweld.com/1clip12.html
     
  11. IdahoDoug

    IdahoDoug

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    Rich,

    How does that work with black coating? I'd think anything atop copper would act as an insulator, vs bare copper. Improving heat transfer by adding a layer seems anathema.

    I couldn't see the video (I have an older Mac) - bummer. When you say 'solder coated copper' are you saying the copper fins are actually uniformely coated with solder somehow? I thought they were simply soldered onto the tubes and otherwise bare copper with a black paint. Kinda interesting if you look closely at the fins - they're finely slitted for even more surface area to shed heat. Pretty cool.
     
  12. Rich

    Rich

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    In the same manner that black surfaces better absorb heat black surfaces also better radiate heat.

    The video is a guy demonstrating their solder being used to quickly repair a couple of dozen holes punched in an aluminum radiator.

    From what I have read, the solder on the tubes of a brass copper radiator significantly reduces the heat transfer effeciency of the copper. So the charts you see of the transfer rate of comparing pure aluminum to pure copper are not representitive of what happens in a real radiator. Again, this is info I have read while researching radiator sludge.

    For your comparitive testing you want to get one of these: http://www.etcenvironmental.com/tss_autorad.php
     
  13. Rich

    Rich

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    Reading the specs for the tester, it dosen't work with a Mac. :)
     
  14. semlin

    semlin discouraged user

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    Doug, not a bad idea but you can also do the test with the rad in the vehicle. Just have everyone start cold and idle the trucks for a preagreed time (5 minutes). Leave them to sit for a preagreed time and pop a thermometer in there. You need three sets of samples

    93/94 with stock rads
    95-97s with stock rads
    95-97s with 93/94 rads

    strictly speaking you don't need the pure 93/94 data points to test the efficiency of the later rads but they might be interesting. This might also give folks a baseline for testing their vehicles for a blocked rad or faulty cooling system

    say 3-5 data points each to adjust for differences between vehicles

    I'll run the test on my 93 if you set the parameters
     
  15. RavenTai

    RavenTai

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    That is the crux of it all, the early radiator is called "brass", aluminum conducts almost twice as much as standard yellow brass. But copper conducts almost twice as much as aluminum. So copper has almost 4 times the thermal conductance of brass.

    on a friends Tacoma the fins were not as well painted and at an angle you could clearly see a copper reddish tint, I looked at another users 93 land cruiser and could not see the base metal even at an angle as it was well painted,

    if the radiator was sourced locally during manufacture you can draw any conclusion you want to about the quality of Japanese vs California made Toyota's

    I would say yes to both. at some point the bare corroded radiator would be less efficient than the painted one, some time after that it would rot through and spring a leak, when this would happen I don’t know, probably in a salt environment only a few years, in the southwest maybe not the lifetime of the truck.

    on a side note, aluminum is the standard for computer cooling cheap easy to work with and light weight, but high end heat sinks are made from copper, there is a Thermalright SLK-800 in my main computer, copper allows the fins to be much thinner and still conduct heat to all areas of the fin, thinner fins allows for more fins and therefore more total surface area in contact with the air, air is a piss poor cooling material, the more hot metal you can get in contact with it the more you can make use of it.
     
  16. Rich

    Rich

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    You would need to be able to measure and control the heat input into each radiator, measure and control the airflow through each radiator, and measure and control the ambient temperature in order to have data sufficient to compare the radiators.
    Would also need to repeat at various rates of heat input and airflow to get an understanding of how they perform over various vehicle operating conditions.

    Would be easier I somebody connected could just get Toyota to spill the beans.
     
  17. Rich

    Rich

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    I believe when one refers to a brass/copper radiator it is the tanks that are brass and the tubes are copper.
     
  18. IdahoDoug

    IdahoDoug

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    Sem,

    The running cooling efficiency of the rads would vary more based on some uncontrolled variables. Things like how much heat's going into the rads will vary based on the state of the engine's tune (poor gas, poor combustion due to old plugs or cylinder valve deposits). Then an idle variation of 650 vs 600 would provide nearly a 10% flow rate variation. A clogged vs clean rad would have higher coolant flow speed, but less flow volume. Good thermostat/old thermo. What % coolant vs water will impact things, how old the coolant is, etc etc. So I'm thinking this would simply have too many variables that cannot be controlled - agree?

    Even with the engines off, there will be convection circulation, and several above variables remain.

    I'm thinking pure water at an exact temp, fill the rad and measure the temp at a few elapsed times. This is about as simple a 'heat shedding' test as there is, and if I do it simultaneously with my two and perhaps we can find two people with newer aluminum rads, we'll have something. What say ye?

    DougM
     
  19. Rich

    Rich

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    A static test won't be measuring the effect that air moving through the core has on cooling. This is a major factor in real world performance.
     
  20. semlin

    semlin discouraged user

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    i agree there are a lot of variables. The benefit of my approach is a big sample size to average it out. I figured with enough samples you'd see some outliers and an average in the middle. I also like your idea of focussing on the rate of heat shedding and taking several timed samples once the rad cap came off. The elapsed differences would be revealing. even then, you are right though that coolant differences might be trouble as they could have more impact than the rad design.

    The only trouble with your test is that unless you use brand new rads your sample size is too small to spot anomalies from blockage.

    rich maybe you could put a fan in front of the radiators?
     
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