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Boxer owners ?

Discussion in 'Technical Q&A' started by parkerfe, Mar 30, 2004.

  1. parkerfe

    parkerfe F1 World Champ

    Sep 4, 2001
    12,887
    Cumming, Georgia
    Full Name:
    Franklin E. Parker
    Are you using a 0.9 bar or 1.1 bar radiator cap? The manual calls for a 0.9 bar cap, but TRutlands has advised that a 1.1 bar cap will keep your car a little cooler.
     
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  3. jselevan

    jselevan Formula 3
    Rossa Subscribed

    Nov 2, 2003
    1,854
    I found that I lost coolant with .9 Bar. However, the expansion tank "balloons" when using the 1.1 Bar. I have had two expansion tanks balloon with 1.1 Bar, and numerous other owners have commented on it. Seems to be a design flaw.

    Jim S.
     
  4. parkerfe

    parkerfe F1 World Champ

    Sep 4, 2001
    12,887
    Cumming, Georgia
    Full Name:
    Franklin E. Parker
    I use the 1.1 bar and have no problems with the header tank ballooning. It seems to me that a hose would burst before the steel header tank would balloon ?
     
  5. Drew Altemara

    Drew Altemara Formula 3

    Feb 11, 2002
    1,373
    Tuscaloosa, AL
    Full Name:
    Drew Altemara
    1.1 bar is what my cap reads.

    Drew
     
  6. jselevan

    jselevan Formula 3
    Rossa Subscribed

    Nov 2, 2003
    1,854
    One would think, wouldn't they. However, the internal surface area of the header tank, and its large flat surface (relative to the cylindrical shape of a hose) lends itself to "expansion." I have seen these tanks expand on several Boxers, not to speak of two of my own. I replaced my tank with a brand new one (as it was leaking), and within a few miles of initial use the new tank had expanded. Take a close look at yours to see if it is distorted.

    Jim S.
     
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  8. WaltP

    WaltP Formula 3

    Nov 1, 2003
    1,466
    Cape Canaveral/Atlanta
    Full Name:
    Walt P
    I would think the lower the pressure the better it would be on all your hoses and expansion tank. I don't believe adding pressure increases anything but the boiling point which can give you a safety margin if you are running straight water with no anti freeze and are close to 212 degrees.
     
  9. kdross

    kdross Formula Junior
    Silver Subscribed

    Feb 10, 2002
    872
    NJ
    Full Name:
    Ken
    I have a 308QV and just ordered a new radiator cap from Algar. My old cap was rated at 0.9 bar, and the new one was rated at 1.1 bar. I called Algar and they told me that the .9 bar cap had been replaced and "updated" with the 1.1 bar cap by Ferrari. So as of today, the 1.1 bar cap is the OEM cap for the cars.

    Ken
     
  10. GaryReed

    GaryReed F1 Rookie
    Silver Subscribed

    Feb 9, 2002
    3,075
    Seattle
    Full Name:
    Gary
    Frank,

    My cap is stamped 1.1 and I haven't had any cooling problems at all.
     
  11. jselevan

    jselevan Formula 3
    Rossa Subscribed

    Nov 2, 2003
    1,854
    Walt - while the coolant at the transducer may not be at 212 degrees, the water flowing past the combustion-area may be at a higher temperature. The system is closed, thus the pressure is uniform throughout. As mentioned, this raises the boiling temperature (pressure being an independent variable, along with molar concentration of antifreeze as an independent variable). Thus, the greater the system pressure, the less likely is local boiling. The downside to much greater pressure is hose integrity, propensity for leaking, and water pump efficiency.

    I have heard that the factory had called for 1.1 Bar caps to replace the .9 Bar caps. My experience of venting at normal operating temperature supports this recommendation. The only downside has been the ballooning of the expansion tank.

    Jim S.
     
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  13. WaltP

    WaltP Formula 3

    Nov 1, 2003
    1,466
    Cape Canaveral/Atlanta
    Full Name:
    Walt P
    I agree with what you are saying. That is why I said the lower presure the better IMO. This would possibly make it necessary to keep the anti freeze up a bit. When I was a kid and my Firebird had a radiator leak I would run without a cap at all to keep from pushing the water/anti freeze mix out and never once overheated. I did have to add water to make up for evaporation.
    Walt

     
  14. parkerfe

    parkerfe F1 World Champ

    Sep 4, 2001
    12,887
    Cumming, Georgia
    Full Name:
    Franklin E. Parker
    The BB512i manual does call for a 0.9 cap and TRutlands does have them for sale. My car currently has a 1.1 cap on it.
     
  15. WaltP

    WaltP Formula 3

    Nov 1, 2003
    1,466
    Cape Canaveral/Atlanta
    Full Name:
    Walt P
    The difference between 1.1 bar and .9 is almost 2 psi and when you figure the surface area of the expansion tank that is quite an increase. The boiling boint of water only (no antifreeze) goes up from about 245 degrees at .9 Bar to about 251 degrees at 1.1
    I don't see the advantage of increasing the pressure but I'm sure Ferrari has a good reason.
     

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