68 Mustang over-heating after upgrades

Discussion in 'Classic Mustang Specific Tech' started by jerthemost, Jun 12, 2011.


  1. jerthemost

    jerthemost Banned

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    i think rad is copper not brass which conducts better than aluminum. copper bends brass does not. i do have a shroud plastic with fan half way in.

    distributor advance is connected to proper place now on carb.

    plugs were changed while in shop because plugs they put in before were too short. plugs that came out were white indicating lean.

    do not understand what you mean by degreed the cam. please explain.

    mech had disconnected vac advance but i will try it again.

    good suggestion on new aluminum radiator but would like to hear from more of you on what you suggest. thanks a million guys.
     
    #21
  2. 2+2GT

    2+2GT Well-Known Member

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    No radiator shops and your mechanic cannot adjust a distributor? Where are you? There's an excellent radiator shop near here, he can do 'bout anything. And the Mustang shop near here does distributors all the time. Distributor timing is critical to performance, which could include overheating. A very cost-effective piece of work, I have seen total dogs turned into tigers with only distributor adjustment. In my experience, parts are rarely required, unless lateral runout indicated the need for a new shaft bushing. I'm definitely concerned about your mechanic if he disconnected the vacuum advance.
     
    #22
  3. robbz28

    robbz28 Member

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    Yeah...u know what I mean...I do that ALL the time...I meant to say copper not brass, copper has a higher conductivity rate than aluminum, thats why they use it in most wiring.
     
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  4. robbz28

    robbz28 Member

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    I'll give the mechanic the benefit of the doubt that maybe he had disconnected the timing when he was setting it...seen a lot of guys set timing like that, perhaps forgot to hook it back up...then again he might just not know what he's doing...it's amazing to watch these dyno pulls when guys adjust their timing by 2 degrees and squeeze out 20 more horsepower.
     
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  5. 2+2GT

    2+2GT Well-Known Member

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    Speed shops come and go, but a friend of mine has been in the biz for 20 years, when he set up his shop he spent the bucks and had a chassis dyno installed in the floor. Can simulate any driving condition, even wide open throttle under load, while he walks around the engine and tinkers, or looks for hot spots in the exhaust, etc.
     
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  6. robbz28

    robbz28 Member

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    I would HAPPILY lay down the money to have my car tuned on a chassis dyno...there just isnt one short of a 4 hour drive from me, that I'm aware of anyway.
     
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  7. Loftus

    Loftus New Member

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    How to Degree A Cam - Lunati Power

    This is one of the better how too's on degreeing a cam.
    Unlikely to cause overheating, it could be a factor. It's a big factor in making power.
    It's my belief if the car didn't over heat before, it's something that has just been done.
    The next thing to fix on MY car , is the last thing I worked on.(haha)
    Don't spend big $$$$ until you have tried all of the cheap(er) stuff.
     
    #27
  8. jerthemost

    jerthemost Banned

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    i cranked the car this morning and let it run up to temp, 190, while purgeing air out of cooling system with rad cap off. There was a lot of air just like before when i brought it home. I put a thermometer in top of rad and showed about 10 degs hotter than my temp guage which has sensor in the intake manifold at the front of the engine. I did notice my theremostst opened at 160 by the temp guage, didn't have thermometer in rad at that time. I should have a 180 or 190 t'stat. I will ask the mech what t'stat he put in, supposed to be hi-flow of some kind. Will it matter much if t'stat is not 180 or 190? I have heard it is not good to run an engine too cool. I will keep purgeing air by letting it cool down then run back up to temp and massage rad hoses while running. I notice i am getting air out of radiator fill hole almost continuously while it is running even when not massaging the hose. Before when got the air out it ran about 25 to 30 deg cooler or so it seemed. Will post another update later today probably. By the way this mech does have a dyno but i am sure he did not use it to tune my car back up because he charges $75 just to use it.
     
    #28
  9. jerthemost

    jerthemost Banned

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    Finally drove it to town

    after 2 days of purging air i drove the car to town yesterday, about 60 mile round trip. Could not run a/c but in 95 deg outside only got to 200 degs going to town and in traffic. Came back on the interstate at 60 mph and outside temp 100 degs. Got up to 205 degs untill i slowed for my drive and went to 208. Pusher electric fan should for sure make a difference in traffic. And i think i need the full 3- 1 inch core aluminum radiator to be able to use a/c.
     
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  10. robbz28

    robbz28 Member

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    Dont know of anyone that makes a 3 row 1" core aluminum radiator (it would be nearly 4 inches thick) a 2 row 1" core aluminum will be what you need. If you are still running that factory 2 row copper then the new Rad will definately bring you down 15-20 degrees. A thermostat operated electric fan would also be helpful in heavy traffic situations.
     
    #30
  11. iskwezm

    iskwezm Advanced Member

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    not sure why your having so many issues, but i went through the same thing years ago.Drove mine to a car show yesterday, idled in line for about 20-25 minutes and never saw more then 166*. I even turned my fan off to let it warm up every once in a while.
     
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  12. MitchGT

    MitchGT Member

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    I would start with re-jetting your carb. you said the old plugs were white, which is lean. you then added better heads and bigger cam, which move more air, which makes it even leaner. start with that first. lean engines run hot!
     
    #32
  13. horseballz

    horseballz Member

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    With as much air purging as it seems you are doing, it sure is sounding suspiciously like a head gasket issue such as poor sealing/leaking or other. Are the squared off tabs (protrusions) of the head gaskets sticking out at the front of the engine or the rear? I realize that some brands of head gaskets don't have the same squared off ends, but maybe we can track down the brand and determine whether or not they are truly installed correctly.
    Just Curious,
    Gene
     
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  14. jerthemost

    jerthemost Banned

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    Timing and running lean questions

    How can i test my distributor to see if it is advancing like it should? Maybe i need a new distributor. If the one i have now is not advancing properly would that cause car to run hot?

    I am beginning to think my problem is timing and carb running lean. I have been investigating radiators and it seems a heavy duty rad for my car is about 24"x16". My current rad is 24x17 with 2 full 1" cores copper which is better than aluminum assuming my rad is clean of course. I ran very cold before upgrades with a/c on and in hottest weather here in Houston area last summer. So if the rad i have now is about as big as i can get my problem must be elsewhere. granted i may need to add electric fan for traffic and can do that but i want to make sure problem is not elsewhere before buying fan and new radiator.

    so any help on checking out the timing and carb/lean issue would sure be greatly appreciated. And is it complicated to change jets?
     
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  15. robbz28

    robbz28 Member

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    I bet you have two 1/2 inch cores...they cant make 1" copper cores...thats why they are done in aluminum. If you do have one then its definately one of a kind....the radiator should be around 3 inches thick at the core if they are 1"
     
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  16. PoppyMod

    PoppyMod Member

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    Hi,
    I'll chime in with.....
    Basic cooling requirements
    180 deg. T/S
    50/50 coolant
    3-4 row rad
    Coolant recovery system
    Fan positioned within 1" of the rad
    Fan blades positioned with 50% of the blades within a shroud
    AFR too lean
    Timing not within specs
    "Zero" air in the system. (coolant recovery will eliminate air)
    With A/C you should be running a 14-15 lb cap.
    Insure hoses and clamps can support the increased pressure.
    (FYI, for every Lb. you increase the cap pressure, you raise the boiling point of your coolant 3 degs.)

    Good luck!
     
    #36
  17. bchampion

    bchampion Member

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    Any chance you have under drive pulleys? If so, that could be causing you to run hot too.
     
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  18. PoppyMod

    PoppyMod Member

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    Hi,
    On the chance you missed my details added later.
    Do not throw money at a new radiator unless it is way too small, that is being a OEM sized rad. especially, before insuring you have bascic cooling neccessities.

    You did not mention a "COOLANT RECOVERY SYSTEM"! One of the most important cooling system components. This will purge the air from your system in one or two cycles if you keep the overflow container full.
    We'll assume your mechanic did not block any coolant transfer ports when he installed the intake.
    Good Luck!
     
    #38
  19. jerthemost

    jerthemost Banned

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    Thanks for all the great help!

    borrowed the following because it seems to pretty well cover it. See my comments after each requirement

    Basic cooling requirements
    180 deg. T/S .......... mine is 160
    50/50 coolant ........have flushed & replacing with exact 50% mix today
    3-4 row rad ............. 2 core smaller than i thought. probably 1/2" cores
    Coolant recovery system ....... sounds like good advice will do it
    Fan positioned within 1" of the rad .......... it is
    Fan blades positioned with 50% of the blades within a shroud ...... it is
    AFR too lean ........ what is this?
    Timing not within specs ........ not sure need advice see above post
    "Zero" air in the system. (coolant recovery will eliminate air) .. will purge today with car jacked up in front
    With A/C you should be running a 14-15 lb cap. .......... have 15psi cap
    Insure hoses and clamps can support the increased pressure. ..... been done

    I noticed when i drained system to flush that the cores seemed to be only about 1/2 to 5/8" tubes. Overall thickness is 2" outside to outside the fins so i thought i had 1" tubes. So i think i need at least 2 1" tubes or would 3 or 4 3/8 tubes be better. I have read a lot of conflicting info on the subject. my fan is 6 blade 18" steel no clutch. is that good enough or would it be better to have something like twin 12" electric fans on 24" rad?

    as for the rad, i prefer to stay with in and out on passenger side. Crossflow leads to more expense and problems. the problem is i can find plenty of 20" rads with passenger side config but not many 24". So is 24" necessary?

    The only thing i can think of left that i have not tried is the timing and lean issue and need help on that. Thanks a million.
     
    #39
  20. PoppyMod

    PoppyMod Member

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    Hi
    After adding the recovery system and allowing the engine to go through several heating and cooling cycles, it will purge all of the air in your system. Don't forget to open the heater control to allow coolant to circulate there, as well. Keeping the coolant reservoir full will insure the rad will not suck air into the system during the cool down cycle. You will know your system is optimized when, upon removing the rad cap, coolant is there at the rad cap rubber seal. Once this is achieved, and you are still having cooling issues, then, add a 4 row brass or two row aluminum with two rows of 1" cooling tubes. But, as I may have mentioned, previously, I'm running a 180 T/S, a 4 row brass, with my engine making 392 RWHP and I have zero cooling issues with my temps rarely going over 205 deg on 95 deg Maryland summers.
    I will add, when initially filling your system remove the heater pipe nipple and the temp. sender and the aforementioned heater core. Fill the rad. as usual, then, using a funnel, add coolant through the heater nipple port. This makes maximum coolant available when the engine is initially fired. Obviously, re-install the heater nipple and temp sender.
    BTW, a lean AFR will add additional heat to an engine, as the mix burns hotter. Get the cooling system optimized, then, chase the AFR.
    Good Luck!
     
    #40

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