Oil to water heat exchangers... | FerrariChat

Oil to water heat exchangers...

Discussion in '348/355' started by steved033, Dec 18, 2024.

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  1. steved033

    steved033 F1 World Champ
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  2. Targatime

    Targatime Formula 3

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    Interesting....my plan when I have the engine out is to replace this time bomb part with an aluminum tube. I get that the idea is to warm up the gearbox oil faster, but I don't really anticipate driving my 355 in super cold temps, and I'm fine with the smoother shifting taking a couple mins longer to happen.
     
  3. Rifledriver

    Rifledriver Three Time F1 World Champ

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    Actually the idea is to keep the transmission oil cool which is a very big issue in them. Even with a functioning cooler seeing them with severely cooked oil is not that uncommon.

    And for whatever reason failures in 355 have been pretty uncommon.
     
  4. fatbillybob

    fatbillybob Two Time F1 World Champ
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    Perhaps Ferrari wanted oil/water to have their cake and eat it too meaning one unit to heat and cool the tranny oil in the desired temp window. If too hot oil is the issue ferrari made a poor choice and air/oil would have been and still is the best answer for the problem with zero failure rate vs. the corrosion and other parts damage seen with failed oil/water coolers. I would trade a longer warm-up period for less potential cooler failure damage.
     
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  5. Targatime

    Targatime Formula 3

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    Very interesting -- had always heard it the other way around.
     
  6. Rifledriver

    Rifledriver Three Time F1 World Champ

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    #6 Rifledriver, Dec 21, 2024
    Last edited: Dec 21, 2024
    You heard a very ill educated opinion.

    That would be like saying air to water intercoolers are designed to heat the intake charge.
     
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  7. Rifledriver

    Rifledriver Three Time F1 World Champ

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    Thats like saying air to water intercoolers are to heat the intake charge.
    On a street car especially in the US a small air to oil cooler does very little because the cars are not going fast enough to do much.

    Anyone who thinks the water is used to heat the oil is just not thinking it through.

    190 degree water does a great job cooling 300 degree oil. Quit over thinking it.
     
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  8. fatbillybob

    fatbillybob Two Time F1 World Champ
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    3 parts the air/oil cooler, electric pump, and a fan to provide air flow...
     
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  9. Rifledriver

    Rifledriver Three Time F1 World Champ

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    With logic like that you would be a shoe in for a government job.
     
  10. fatbillybob

    fatbillybob Two Time F1 World Champ
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    No government beaurcrats needed. It's the most reliable way to keep things cool proven by racers every day. There is no surprise that race oil cooling systems look just like the ubiquitous antifreeze based cooling system of radiator, fan, and waterpump.
     
  11. INTMD8

    INTMD8 F1 Veteran
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    I think functionally the original design is good. Seems like very low failure rate but I prefer to remove it. Part of that decision is based on my car being modified. I would have no problem keeping it if closer to original.

    Not sure I would compare it to an air to water intercooler as that would of course be entirely separate from the engine cooling system.

    IMO an oil to air unit properly sized and ducted would perform well. That is what I intend to do.

    Later challenge cars had oil to air and 458 italia, 550, 575,599 (I think)

    Newer cars with oil to water have what looks to be more of a sandwich design than tubes. Not sure if that is a result of efficiency, cost, or both.

    I know the layout of the F355 trans may generate more heat but also has less power and weight compared to some with oil to air.

    If done (switching from oil/water to oil/air) I think it's important to make sure it's fed with fresh air as to not become a heater rather than a cooler.
     
  12. Timmo

    Timmo Formula Junior

    Aug 26, 2017
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    The F355 (and 348) has that unique feature of having the gearbox flanked directly to the engine and with exhaust pipes routed rather closely around it with cooling of the engine bay that may work mostly at illegal pace it is quite understandable that gearbox oil may get hotter than it would on the other cars (550/575/599) where there is quite some distance between the engine and the gearbox, and where exhaust pipes around the gearbox won't be anywhere as hot as on a F355.
     
  13. fatbillybob

    fatbillybob Two Time F1 World Champ
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    In the 348 there was never a cooling problem in the tranny. It had other problem but not a heat issue even in racing. I raced those cars never had an issue there. Here is the 348 challenge book. It says what is legal for the series in 1994 the end of the 348. If there was a heat problem in the box they would have to address it over the series run of the cars would have failed on track. The rules did not allow a cooler for the box.

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  14. INTMD8

    INTMD8 F1 Veteran
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    Yes I mentioned the F355 may generate more heat but still think an oil to air would work if properly ducted as it does on the F355 Challenge.
     
  15. m.stojanovic

    m.stojanovic F1 Rookie
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    There is no reason for any argument here as the transmission oil/water heat exchangers are installed to equally serve both purposes: warm-up the oil initially and later prevent the transmission oil from getting too hot (if and when the transmission oil temperature attempts to climb to above the engine coolant temperature).

    The advantage of this system is that it will not "overcool" the transmission oil but keep it within its optimal temperature range which is approximately between 80C and 100C. A transmission oil/air cooler system would need to have a thermostat which would keep the oil temperature within the mentioned range.
     
  16. Rifledriver

    Rifledriver Three Time F1 World Champ

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    If you say so.
     
  17. Mitch Alsup

    Mitch Alsup F1 Veteran

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    Outside temperature = 10ºF
    Car sat at this temperature overnight.
    Start car and let it idle.
    Water warms to 120º in 3 minutes.
    Gearbox does not get warm until you start driving.

    Thus, while you are sitting there idling, water is warming up the gear oil--because on one side of the heat exchanger you have 120ºF water and on the other side you have 10ºF transmission oil.
     
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  18. INTMD8

    INTMD8 F1 Veteran
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    Would it not only pump gear oil through the cooler when the car is moving?
     
  19. Mitch Alsup

    Mitch Alsup F1 Veteran

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    Oil already in the cooler gets warm and shortens the process, once the car starts moving.
     
  20. johnk...

    johnk... F1 World Champ
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    WSM says it's driven by the main shaft so as long as the clutch is engaged it would seem the pump is working.
     
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  21. Mitch Alsup

    Mitch Alsup F1 Veteran

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    I had forgotten which end did the pumping.

    But if it is as you say, then using transmission in neutral; engine would warm up the tranny without movement.
     
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  22. INTMD8

    INTMD8 F1 Veteran
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    ^ Yes that makes sense. Given it's location I didn't realize it was driven off the main shaft, thanks.
     
  23. m.stojanovic

    m.stojanovic F1 Rookie
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  24. Timmo

    Timmo Formula Junior

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    As already stated, what works on a race car does not necessarily work on a street car.
    That there is not even an oil thermostat between the heat exchanger and the gearbox speaks volume on how quickly gearbox oil must only just get up to temp already.
     
  25. Portofino

    Portofino Formula Junior

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    #25 Portofino, Dec 26, 2024
    Last edited: Dec 26, 2024
    These g box oil - to coolant water heat exchangers / coolers , for clarity are NOT found on the 348 ?

    Thinking as the cars age a potential failure point and pretty catastrophic at that .

    You get heat exchangers in boats ( all types btw oil / coolant and raw water ) …..when not if they fail the bearings are gone = rebuild . Often a repower is a 6 figure sum ! Water esp sea water in the sump isn’t a fantastic mix in terms of longevity . Coolant isn’t far behind .

    To mitigate this potential failure the service regimes have timely services wherby the coolers are pulled and seals replaced …..@ regular intervals .

    Is there a service regime with the g box oil to water coolers in F cars here ?
     
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