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250 Water Pump

Discussion in 'Vintage (thru 365 GTC4)' started by christc, Nov 15, 2020.

  1. christc

    christc Formula Junior

    Mar 3, 2013
    293
    Germany
    Hello All,

    I do have two question for the experts and hope you can help me there. I have fully reconditioned my 250 Gte engine and now have it running on a small self build test rig - see photo.

    It is running fine but after some time water started to come out of the seep hole of the water pump. I overhauled this with a kit from GTO and they said they use this without problems. I did therefor not use the old spring as recommended in other threats.

    Now that I have to do it again I was wondering if you have experience with the update kits available using the latter seals from 365. I know there are conversions from Bell Classics and Roeloefs. Any experience or recommendations?

    The second question is about removing the pump: do you slacken the cam chain tensioner before dismounting the pump? I would guess so but would like to know what the experts do? I am not sure how much strain the chain puts on the shaft when the water pump is dismounted. It is clear to me the dismounting has to be done carefully to make sure the shaft with bearing at the end stays in the chain housing.

    Any hints welcomed. Thanks a lot.
    Christopher




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  3. TTR

    TTR F1 Rookie
    Silver Subscribed

    Mar 29, 2007
    2,814
    Riverside, CA
    Full Name:
    Timo
    I don’t have much to offer for you Chris, but just recently ran into a problem with water pump service parts readily available for 365 GTB/4.
    The new (reproduction) WP impeller spacer/shaft seal sleeves* for this application appear to be made incorrectly requiring 2 different re-machining procedures to make the useable.
    You might want to check if 250 like yours uses same/similar spacer/sleeve and if they do, closely compare to original one.

    *I had two in-stock, bought within last couple of years from different well established, long time vendors, although both are/were in identical (sealed) packaging with identical part number labels, so presumably from same supplier.

    P.S. I’ve bought/replaced these over the years, but never experienced this problem before, so I assume it’s more recent issue.
     
  4. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
    6,448
    southwest germany
    Full Name:
    romano schwabel
    so you used new spring or no spring? without spring the water pump has to leak


    you not have to remove the complete pump, only the front housing and the propeller, then you reach all and not have to loosen the chain tensioner

    what is the black round box left of the electric fuel pump for?

    how much bar the fuel pump makes?

    what car is this in the second photo with the spoke wheels? looks like a british car?
     
  5. mechaniker

    mechaniker Formula Junior
    Rossa Subscribed Owner

    May 30, 2004
    473
    I would use a waterpump from Modena Motori. Or at leat their gasket set.

    No problems with their parts.


    With other parts suppliers I had not so much success.
     
  6. christc

    christc Formula Junior

    Mar 3, 2013
    293
    Germany
    Timo, Romano, Mechaniker, Thanks for the answers.

    I will talk to Modena Motori, know them from Padua fair.

    To the questions of Romano:
    - yes, used spring supplied by Gto
    - black box is my strobe
    - electrical fuel pump has max. 5 psi/ mechanical not used at the moment in this setup. Will mount and check it as soon as everything else is perfect
    - Triumph TR4A



    I am still interested if there is experience with the kits from Roeloefs or Bell?

    Thanks
    Christopher
     
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  8. 335s

    335s Formula Junior

    Jan 17, 2007
    867
    SF Bay Area
    Full Name:
    T. Monma
    Go to internet and research: “Crane seals” for impeller shafts...

    Almost ZERO car manufacturers make stuff like this-they all buy it from vendors: think tyres, carbs, distributors, dynamics, starter motors!
    That said, it’s just a series of dimensional constraints, spring coefficients etc... they are cheap from genuine suppliers
    Avoid made in China-liability issue(while generally fine, statistical failure rates fall outside allowable norms IMO), which means twice as expensive in most cases.

    ALL the parts houses are doing this: NOBODY has these things “made for us”, strictly off the shelf, manufacturing supply chain stuff....
     
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  9. 1monza

    1monza Karting
    Rossa Subscribed

    Jan 11, 2005
    95
    Manhattan Beach, CA
    Full Name:
    Norbert Hofer
    I stopped using the standard 250 waterpump seals 25 years ago. I convert all my V12 waterpumps to using a 308 2 piece seal I believe it is the same or similar to the 365GTB4 set up. Never have had a problem since.
     
  10. christc

    christc Formula Junior

    Mar 3, 2013
    293
    Germany
    I now have a Roloefs pump conversion. To mount this the complete old water pump has to come out without disturbing the water pump shaft. I got lots of advice about using a pump with daytona style conversion from Dyke. Thanks again.
    I build myself a simple tool to fix the shaft while dismantling the pump. See pictures. Worked fine.

    Christopher
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  11. 1monza

    1monza Karting
    Rossa Subscribed

    Jan 11, 2005
    95
    Manhattan Beach, CA
    Full Name:
    Norbert Hofer
    Looks more complicated then it needs to be.
     
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  13. christc

    christc Formula Junior

    Mar 3, 2013
    293
    Germany
    Actually took about 45 min to do and keeps shaft firmly secured. Better safe then sorry...
     
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