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360 Cooling cirucuit and transmission cooler

Discussion in '360/430' started by Elauqs, Mar 10, 2021.

  1. Elauqs

    Elauqs Rookie

    Jan 4, 2021
    3
    Lyon, France
    Full Name:
    Max
    Hello everyone!

    I just bought my first 360 (which also happens to be my 1st Ferrari ^^), and though the car seems to have been very well taken care of by the previous owner, I am raising a list of all the things I will want to do/check before I start running the car regularly.

    One of my concerns is the infamous gearbox oil/coolant heat exchanger. I am not happy with the idea of having such a time-bomb in my car, and am looking for alternative solutions.

    I saw some people simply deleted it (not a good idea IMHO), or replaced it with a relocated oil/air cooler as found on the 355/360 Challenge cars.

    So far, my understanding is that the cooling system is as follows:

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    So, of I am right, removing the stock heat exchanger (32) would theoretically raise the engine temperature, since the thermostat is supposed to open at a certain temperature once the exchanger has heated the coolant out of the engine; without the exchanger, the engine would needs to heat up more for the coolant to reach the same temperature.

    Can anyone confirm or discard my analysis so far?

    Thanks a lot!
     
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  3. vrsurgeon

    vrsurgeon F1 World Champ
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    Dec 13, 2009
    13,895
    Charleston, SC
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    Curt
    I can't see how removing the transmission heat exchanger is going to have a dramatic effect on the engine temperature or warmup. That 1 liter of coolant isn't going to do too much nor is the heat exchanger going to keep down engine temps.. the big thing with removing it is the effect it will have on transmission oil warmup.
     
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  4. EastMemphis

    EastMemphis Formula Junior
    Silver Subscribed Owner

    May 25, 2019
    882
    Memphis, TN
    Full Name:
    John
    The "time bomb" theory is a bit overblown. If you've had regular coolant changes and the car has been driven regularly, then the heat exchanger can last the entire lifetime of the car. That said, if you have to remove it for any reason, it's prudent to replace it.

    From my understanding, the primary use of the heat exchanger is to heat the transmission oil, not cool it. The transaxle in the 360 is stiff and uncooperative when cold but once warmed up, works pretty well. Deleting the heat exchanger would be foolish and unnecessary, plus it would cause hard shifts into second, probably forever, as the transaxle wouldn't be at the right temperature.

    If you're worried about the heat exchanger, the best advice I've received is to regularly check the coolant reservoir for an oil sheen. If one is detected, then do the heat exchanger immediately and flush the transaxle. Otherwise, just let it do its thing.

    If you have a 2000+ 360 with original headers, that would be a far greater worry to me than the heat exchanger. The header cats failing can cause catastrophic engine damage so you might want to prioritize upgrades to that system instead of the HE.
     
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  5. FlyingHaggisRacing

    FlyingHaggisRacing Formula 3

    Jul 2, 2013
    1,318
    Just got a car in where this has failed, thankfully does not appear catastrophic.

    You would replace #32 with a hose and then locate a dedicated gearbox cooler as you wish, plus ensuring oil temp control (oil thermostat) and adequate cooling of that new rad. To the rear of the air intake tube is one possible location.

    You may accept that the OEM solution helps with warming the gearbox oil from start than a standalone rad solution would.
    Further, track use where higher revs are used will result in the gearbox oil temp rising noticeably, so dumping some heat into the water cooling system is one answer.

    The easy answer is just schedule a replacement of the OEM heat exchanger every 10yrs and not have a worry.
     
  6. Elauqs

    Elauqs Rookie

    Jan 4, 2021
    3
    Lyon, France
    Full Name:
    Max
    #5 Elauqs, Mar 10, 2021
    Last edited: Mar 10, 2021
    Thanks for your inputs.

    I'm aware of the gear oil warmup aspect, and do plan on keeping that if possible. I'll probably end up just buying a new OEM unit for peace of mind. But I like to fully understand how things work (me being an engineer, I guess! ^^).

    And so, IF I choose to remove it, my concern was (with random temp values just to illustrate):
    -With the stock system: coolant leaves engine at, let's say, 80°C. Then goes through heat exchanger and reaches the thermostat at 90°C when it starts opening.
    -Delete the exchanger, and now the coolant needs to leave the engine at 90°C to open the thermostat -> Engine will therefore run hotter than before

    I just want to know if this analysis makes sense, or am I overthinking it? Or just plainly wrong?

    As for the headers pre-cats failing: do the Euro models have them too? Or is it just a US market thing?
     
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  8. vrsurgeon

    vrsurgeon F1 World Champ
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    Dec 13, 2009
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    Curt
    Overthinking it. Leaves engine at 90 deg and goes through the intercooler lets say it cools it down 5 degrees on warmup and then goes to thermostat at 85 degrees. It takes 10 minutes for the temperature differential to equal whereby leaves engine at 120 deg and enters thermostat at 120 degrees. Why is the temperature differential even important. The car doesn't care what the temperature differential is across the intercooler. It doesn't care about warmup time. The car doesn't give a CEL because it takes 10 minutes longer to attain 120 degrees than on a hot day.
    Why would the engine operate at a hotter temperature? The water leaving the engine at the very least enters the thermostat at the same temperature as it leaves the engine without the intercooler? The only way the engine is going to run hotter is if the thermostat didn't open and the hot engine coolant couldn't get to the radiators in front of the car.. Only thing that might get affected is faster warmup. And I'm not convinced the temp differential across the intercooler is that high relatively speaking.

    1999 models don't have pre-cats and euro cars don't have precats.
     
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  9. Elauqs

    Elauqs Rookie

    Jan 4, 2021
    3
    Lyon, France
    Full Name:
    Max
    Why would the engine operate at a higher temperature?
    (Not talking about warmup here, but once everything has reached normal running tempertures. And gear oil temp is always higher than coolant temp, they never stabilize)

    Well, to keep the engine running at nominal temperatures, the thermostat is designed to open at a set coolant temperature that should be taking into account the extra heat from HE added after the engine outlet.
    Without the HE it will no longer be tuned properely.

    If the coolant temp differential in and out the HE is not very high (and I agree with you, I also don't think it is), then indeed I'm overthinking it and it's not a problem.
    But if is, then I'd like to know...

    Then again, this is just a question I'm raising since I never heard of anyone bringing it up when dealing with the gearbox HE...
    I'll probably end up sticking with the OEM unit in the end ;)
     
  10. wbt

    wbt Karting

    Nov 28, 2014
    157
    New Zealand
    Transmission heat exchanger performs a very overlooked but important role in heating the transmission up from a cold start. This is why it's called a heat exchanger, not a cooler. That transmission is designed to run within a certain temperature band. The OEM unit is not hard to replace and lasts a very long time. I replaced mine myself in a day. Not a difficult job.
     
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  11. tazandjan

    tazandjan Three Time F1 World Champ
    Lifetime Rossa Owner

    Jul 19, 2008
    33,601
    Clarksville, Tennessee
    Full Name:
    Terry H Phillips
    Funny, the V12s only have a transmission oil radiator and it is separated from the engine by the length of a torque tube. Transaxle warms up pretty quickly on mine with all those rotating parts.
     
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