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Thread: OverHeating Problem & Plan of Attack...

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    OverHeating Problem & Plan of Attack...

    Hello Fellow Enthusiasts...

    I have a BJ8. New/rebuilt engine. New Thermostat (160) installed. 6 bladed fiberglass fan. New temp guage installed. New texas cooling fan installed. Installed/put in "water wetter" into engine.

    Took the car for a drive yesterday went up to 180, then 190, held for about 5 mins then up to 200 (got on the ^%$# freeway - drove 60 mph - stayed @ 200) got off went to 210... and (*&^%$#$%^&*&^%$##$%$%$#@% all over... this time there was oil as well (probably separate issue) but a bunch of oil came from the rt side (looking from front) of the engine - possibly head gasket.

    Ok - so I have an overheating problem (I live in Colorado).. But there is something else going on here.

    My plan of attack was to:

    1) completely drain/flush entire cooling system & engine block - flushing until clear.
    2) re-run the car with just water in the engine to see how it runs
    3) drain engine, remove thermostat, see how car runs with no thermostat installed at all.
    4) next, remove radiator have it checked @ shop, possibly re-cored (i think it's been done, but assumptions are the ___ of all ____)
    5) move to antartica and start a "healeys on ice" club...

    any suggestions and or feedback would be greatly appreciated. The oil issue is greatly concerning - I'm hoping I didn't warp the head yesterday... [img]/ubbthreads/images/graemlins/frown.gif[/img]

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    Moderator Editor_Reid's Avatar
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    Re: OverHeating Problem & Plan of Attack...

    I had/have a very similar problem with my BJ8. The car runs and drives absolutely like new in all respects, except that coolant temp.

    I replaced the thermostat and radiator cap (with a correct one of 7 lbs. that I verified is indeed pressurizing the system), installed a Texas Healey Kooler fan, put in coolant composed of only about 20-25 percent anti-freeze, and had the radiator checked out at a local radiator shop (where they were honest enough to tell me that it was "like new" and didn't need to be rodded out). The water pump seems to be working fine, and with the radiator cap off, and after the thermostat opens, you can see the coolant is moving pretty well. The ducting to direct incoming air through the radiator is present. We checked the temp gauge against a meat thermometer placed in the radiator top, and noted that the gauge was reading 20 degrees high! I carefully removed the needle from the gauge and replaced it in the "correct" position to match what the meat thermometer read.

    The strange part is that if you top up the radiator, the engine will still spit out some coolant when shut off. It has done this a couple of times and the coolant level is down to where it doesn't do that anymore, but I haven't been caught in traffic on a hot day... yet. I'm not looking forward to it, but it is going to happen.

    We shall see, but I don't know what else to do, and I still have the impression that there is a problem that hasn't really been fully dealt with yet.

    [img]/ubbthreads/images/graemlins/confused.gif[/img]
    Reid Trummel
    Editor, HEALEY MARQUE magazine

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    Re: OverHeating Problem & Plan of Attack...

    Thanks... I actually checked the temp both in the radiator and with a digital thermometer so the guage is reading correctly... Of course I could put one of those really cool air cooled radiators (like you see on Vw buses) on the back...

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    Great Pumpkin Keoke's Avatar
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    Re: OverHeating Problem & Plan of Attack...

    Hi Noutlaw/Reid,for the BJ8 cars that seem to overheat the only solution I have found in addtion to what you presently have is to replace the radiator with a 4-or-5 cored serpentine one. Do not fill the radiator above the level it attains after it spits out the excess unless you fit an overflow bottle.If the BJ8 engine overheats it will emit oil on the right hand side of the engine about the middle of the generator bracket. Solve the heating problem and you may be ok---Fwiw---Keoke

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    Yoda Dave Russell's Avatar
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    Re: OverHeating Problem & Plan of Attack...

    [ QUOTE ]

    The strange part is that if you top up the radiator, the engine will still spit out some coolant when shut off. It has done this a couple of times and the coolant level is down to where it doesn't do that anymore, but I haven't been caught in traffic on a hot day... yet. I'm not looking forward to it, but it is going to happen.

    We shall see, but I don't know what else to do, and I still have the impression that there is a problem that hasn't really been fully dealt with yet.

    [img]/ubbthreads/images/graemlins/confused.gif[/img]

    [/ QUOTE ]
    Hi Reid,
    what you describe is pretty much to be expected. The coolant will expand about 1/2 quart or more as it heats up. If the radiator is completely full when it is cold, the expanding coolant has no where else to go but out the pressure cap overflow & on the ground.

    The remedy, if you want one, is to install a catch tank or coolant recovery can so that the overboard coolant has a place to go. With a coolant recovery system, the overboard coolant is drawn back into the radiator as the system cools.

    For this to work, the radiator cap needs an additional top seal. Several non original caps such as the Napa #703-1411 have a good top seal. Most cars made after the 60's have this arrangement as stock from the factory.

    The original intent on the Healeys was to just leave the radiator top tank about a quart shy of full when cold. This prevents the overflow but reduces cooling capacity a bit & allows air to circulate with the coolant.

    As Keoke said, if you drive in a hot climate or do slow traffic driving, the only solution to high running temperatures is to install a higher capacity radiator core. This, in combination with a "good" fan, will cure almost all overheating problems.

    I believe that TransPro will custom make a new & much more effecient radiator core to fit your existing top & bottom tanks, & ship it to your radiator shop in just a few days. https://www.transpro.com/prod_radcores_ready.htm
    D

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    Re: OverHeating Problem & Plan of Attack...

    Thanks - Keoke - is the item you are talking about a new product? where might i find one??? I noticed on victoriabritish they have a New Radiator, it's new not just re-cored...

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    Great Pumpkin Keoke's Avatar
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    Re: OverHeating Problem & Plan of Attack...

    OK, if you two decide to add the larger radiator.There are four core units that will fit within the existing side frames.However, I have found these inadequate.Consequenty, I cut the front and rear flanges off the side frames {Do not let the shop beat these flanges out flat they will look like the [img]/ubbthreads/images/graemlins/devilgrin.gif[/img]} and have some 3/8" X 5/8" right angle stock bent up. These are cut to length and encase the wider 5 core just like the originals when soldered to the side frames, you can not tell it from stock.-Sneaky -Keoke- [img]/ubbthreads/images/graemlins/grin.gif[/img]
    1966 Daimler V8 Saloon; Safely Fast, Built to Last & and; Smooth as Glass.
    1966 BJ8 [ 2 ] Lil Red & Miss bLU
    1985 XJ6 Saloon
    1948 & 70 Lincoln continentals
    1973 Volvo P1800ES

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    Yoda Dave Russell's Avatar
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    Re: OverHeating Problem & Plan of Attack...

    At the risk of beating this topic to death:

    Radiator type of construction & cooling ability involve more than just the number of tube rows & area.

    Tubes that are narrower but longer in the horizontal plane cool better.

    Tubes which are spaced more closely together provide more cooling surface than tubes that are more widely spaced.

    Tubes can be placed in line or staggered.

    Plate type fins provide less fin area exposed to the air flow than serpentine fins.

    As an example for my BN2 radiator, yours will obviously be different:
    My 100-4 radiator core was 14H X 19 W x 2 3/4 thick & had five rows of widely spaced 1/2" tubes, 150 tubes total, with plate type fins spaced at 10 fins per inch. My replacement core is 14H x 19 W x 3 thick, has four rows of 48 more closely spaced but wider 5/8" tubes, 192 tubes total, with serpentine fins spaced at 14 fins per inch. This represents about 60% more tube area & 40% more fin area. The new core was custom made by TransPro.
    D

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    Re: OverHeating Problem & Plan of Attack...

    You may not want to run the car with no thermostat. There needs to be some restriction to allow the radiator to do it's work. I've heard of taking the innards out of a stat, but I never tried it.

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    Re: OverHeating Problem & Plan of Attack...

    Did the engine overheat before you had it Rebuilt?

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    Re: OverHeating Problem & Plan of Attack...

    When I awakened my BJ8 from its 25 year slumber, I had the same problems, except I didn't get any oil out the diptstick tube. Turns out I had the wrong plugs (N-8 instead of UN12Y -- way too cold) and timing was retarded, or maybe it was the driver, I'm not sure which. After installing the correct plugs and advancing the timing until I got a slight ping on hard acceleration in 4th, heating problems went away. I live in Oklahoma, where 100 degree days are not unusual. My experience was that every time I advanced the timing a little bit, I had to retune the carburetor mixture, drive a few miles and then check the plugs to see if their tips were the right color. Too rich or too lean mixture can also cause heating problems. If you haven't already done so, you might want to try tuning before making a sizable investment in a modified radiator.
    Rogers Abbott
    British car fanatic

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    Re: OverHeating Problem & Plan of Attack...

    Hi, Noutlaw -

    I would suggest that before you expend too much effort to solve your overheating problem you verify that your temp gauge is accurate. After a professional rebuild of my gauge several years ago, I began to experience "overheating" problems. I tried everything I could think of to cool the engine down: Texas Kooler, radiator shroud, Water Wetter, pure water, 160-deg. thermostat, overflow system, praying, cussing....
    Only when I bit the bullet and pulled the gauge to check it in a pan of boiling water (I live at sea level, which makes it easier) did I discover that it was reading about 15 deg. too high. I had assumed that the pros who rebuilt the gauge calibrated it correctly. After I did the calibration, my overheating problems disappeared.
    By the way, the 160 thermostat will not do anything more than a 180 to cool the engine. What it will do is make the engine run too cool when the ambient temps are cool. After calibrating the gauge, I replaced my 160 stat for that reason, and now the 180 is just right.

    Steve Byers
    HBJ8L/36666
    BJ8 Registry
    Havelock, NC USA

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    Re: OverHeating Problem & Plan of Attack...

    Sorry to jump on this with both feet, but it's an old-wives' tale, just like "the wheel bearing spacer strengthens the axle". Removing the thermostat will not cause overheating problems due to "not enough dwell time for the coolant in the radiator". Heat transfer is proportional to coolant flow (both water and air). The thermostats are there to restrict the flow until the engine reaches operating temperature, at which point they are wide open and essentially out of the system anyway. Many of the cars shipped to "hot" climates were shipped without thermostats, as indicated by the parts manual. Running without a thermostat will make the car slow to warm up, and a little cooler at operating temperature.

    Steve Byers
    HBJ8L/36666
    BJ8 Registry
    Havelock, NC

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    Re: OverHeating Problem & Plan of Attack...

    Hey Steve,
    Good to see you over here for a change. [img]/ubbthreads/images/graemlins/savewave.gif[/img]

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    Re: OverHeating Problem & Plan of Attack...

    Wow, thanks guys [img]/ubbthreads/images/graemlins/smile.gif[/img] couple of things:

    1) it's reading ok on the gauge - i already replaced it.
    2) i agree with the no thermostat comments - i used to run my 1937 dodge w/o a thermostat and it ran just right... however they are there for a reason and help balance the engine, oils, etc.
    3) the sparkplug/timing comment is a great one - I'll check on that asap.
    4) I did talk with the owner of antique radiators in maine - they will custom build a radiator for me - that according to them you won't be able to tell that it's internally a new radiator. He indicated between a 15 and 25 degree temp drop... of course that's really expensive [img]/ubbthreads/images/graemlins/frown.gif[/img]
    - I'll check with transpro... maybe the combination of flushing, plugs and radiator core would fix it...

    Thanks for all the help... - if this doesn't work there maybe a newly finished healey blue 67 healey for sale soon... wife vs. car (as we all know)...



    3)

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    Yoda Dave Russell's Avatar
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    Re: OverHeating Problem & Plan of Attack...

    [ QUOTE ]
    Removing the thermostat will not cause overheating problems due to "not enough dwell time for the coolant in the radiator". Heat transfer is proportional to coolant flow (both water and air). The thermostats are there to restrict the flow until the engine reaches operating temperature, at which point they are wide open and essentially out of the system anyway. Many of the cars shipped to "hot" climates were shipped without thermostats, as indicated by the parts manual. Running without a thermostat will make the car slow to warm up, and a little cooler at operating temperature.
    Steve Byers

    [/ QUOTE ]
    Hi Steve,
    I partially agree with you. "too fast for proper heat transfer" is against the laws of physics. If the coolant spends less time in the radiator to lose heat, it also spends less time in the engine to gain heat.

    I don't quite agree on the wide open thermostat part.

    The thermostat being wide open still presents considerable restriction to water flow. You only have to compare the flow area of the open thermostat to the area without the thermostat to see this. About 40%-50% less area with the open thermostat than without it. With many cars it is recommended that if the thermostat is removed, replace it with a restrictor sleeve.

    The reasons that a restrictor at the engine water outlet helps are two-fold.

    1- The restrictor puts higher dynamic pressure on the block & head. The local pressure in the block will be much more than the static cap pressure. Often 10 psi higher. This increases the local nucleatic boiling point at the hot spots, especially in the cylinder head. Once the nucleatic boiling point is exceeded at a hot spot, the steam forms a very efficient insulator between metal & coolant. High performance engines often have higher flow pumps, with the resulting higher localized water jacket pressures.

    2- The restrictor raises back pressure on the water pump inlet. (Reduces the suction) At high water pump (engine) speeds this has the benefit of reducing water pump cavitation & the resultant bubbles that are formed in the coolant. Reduced cavitation increases pump effeciency.
    D

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    Re: OverHeating Problem & Plan of Attack...

    One Follow Up on this topic...

    I am having my radiator sent to Antique Radiator Restorations in Maine. they are indicating that they can install a new parrallel flow designed core into the radiator - and possibly have it as a double core design. I am going to have them do some tests before and after plus document what they are doing and will post back here when completed - about 4-6 weeks from now...

    fyi

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    Great Pumpkin Keoke's Avatar
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    Re: OverHeating Problem & Plan of Attack...


    I sure thought you were heading for the garage to pull the thermostat out Dave.---Keoke [img]/ubbthreads/images/graemlins/lol.gif[/img]

    OH MY gosh You forgot to tell him about the tube over the axel bit too.---Keoke
    1966 Daimler V8 Saloon; Safely Fast, Built to Last & and; Smooth as Glass.
    1966 BJ8 [ 2 ] Lil Red & Miss bLU
    1985 XJ6 Saloon
    1948 & 70 Lincoln continentals
    1973 Volvo P1800ES

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    Re: OverHeating Problem & Plan of Attack...

    Quote Originally Posted by Randy_Gay View Post
    You may not want to run the car with no thermostat. There needs to be some restriction to allow the radiator to do it's work. I've heard of taking the innards out of a stat, but I never tried it.
    While you do not necessarily need a thermostat you do need a restrictor or the coolant will fall through the radiator too fast without much cooling.

    The entire purpose of the thermostat is to allow the engine to warm up to operating temperature more quickly which it does by closing off the coolant flow and keeping it in the head. Then once open it restricts the flow to allow the radiator to do its job efficiently. In warmer climates you do not actually need a thermostat but you still need to restrict the flow to allow the radiator to do its job efficiently. This can be accomplished by inserting a restrictor where the thermostat would normally go. You can make your own one of these by taking an old thermostat and cutting the guts out of it (the spring and tin part that closes it, takes 5 minutes or less with a hacksaw) essentially making it into a tin(brass) doughnut that you reinstall in place of the thermostat. This is an old racing trick. This will flow slightly better because the innards are no longer in the way, but it will restrict the flow to the correct amount so everything cools correctly. I can verify that this technique doe work.

    Cheers,
    Dan M.

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    Re: OverHeating Problem & Plan of Attack...

    Hi All,

    The thermostat needed is a Sleeve thermostat and if you are going to eliminate the thermostat, I suggest you use a thermostat bypass blanking sleeve. Keep in mind that the engine has a bypass channel that diverts aprox. 25% of coolant flow from passing through the radiator for faster warm-up. Without the sleeved thermostat or a bypass blank, you are leaving this channel open and loosing coolant flow through the radiator.

    Ray(64BJ8P1)

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