Kitfox Aircraft Stick and Rudder Stein Air Grove Aircraft TCW Technologies Dynon Avionics AeroLED MGL Avionics Leading Edge Airfoils Desser EarthX Batteries Garmin G3X Touch
Results 1 to 7 of 7

Thread: Rotax 582 Radiator Cap WOES

  1. #1
    JustPlaneMike's Avatar
    Join Date
    Apr 2020
    Location
    Raleigh NC area
    Posts
    20

    Default Rotax 582 Radiator Cap WOES

    The 1993 KitFox II with a Rotax 582 model 90 gray head I recently purchased and now working on the conditional inspection . The Radaitor Cap was the 6-8 PSi one that needed to be changed to the 13 psi one. Searching all forums I was lead to a cheap alternative which was a Motorbike Radiator Cap A Triumph part number T2108005 I found one and ordered it For around $25. Great. well when I got it it was to small. was the information wrong? So much time was wasted looking for it I decided to go ahead and and order the Rotax part number 922-072 from Leading Edge Airfoil. Well guess what it to was to small and the Triumph was an exact match.
    Leading Edge suggested calling KitFox cause he thought they shipped out the caps with the kits and that it was proably a standared automotive Cap. I was able to supply the Listed part number from the build manual E-62- Kitfox did not have a match for the Cap- He did search and found some histroy that Denny AeroCraft, purchased the radiator caps from a local parts store.They did not use the cooling system from Rotax. no parts number available. Wonder how much other automotive parts were used? I going to return part to Leading edge unless someone want to buy it, I also have the Triumph clone cap for sale.
    So before I go to the auto parts store and They ask what vehicke is it for? so they can lookit up on the computer cause they don't know how to find parts otherwise.
    Does any one have an autopart number for the automotive cap I need ?
    Ill try to add photos
    Ist photo is the Triumph Cap any my old Cap 2nd photo Triumph part number 3 filler neck on plane 4 My cap and the Rotax Cap,
    Thanks for any feedback and hope this helps some of us with the older kits
    Attached Images Attached Images
    Last edited by JustPlaneMike; 01-27-2021 at 07:37 PM. Reason: Spelling

  2. #2
    Senior Member 109JB's Avatar
    Join Date
    Mar 2019
    Location
    Morris, IL
    Posts
    484

    Default Re: Rotax 582 Radiator Cap WOES

    When I had to replace the cap on my 582 powered kitfox, I just took the old one to an auto parts store and told them I wanted a 13 psi cap. Guy walked in the back and came out with a 13 psi cap. Now this was a sort of old time auto parts store with an older guy who actually looked like he knew how to work on a car, not Autozone or O'Reillys where the workers are high school kids who think working on a car means putting bullet hole stickers on it, or installing the largest speaker known to man.
    John Brannen
    Morris, IL
    Sonerai IIL (Single Seat)
    Kitfox 3/4 1050 - Rotax 582 (Back Flying and sold)
    Kitfox IV 1050 - Rotax 582 (sold)
    Kitfox IV 1200 Speedster - Rotax 912 UL (project)
    Piper Twin Comanche (Sold)
    Glasair 1 FT (Waiting to start)

  3. #3

    Join Date
    Jun 2018
    Location
    San Diego, CA
    Posts
    75

    Default Re: Rotax 582 Radiator Cap WOES

    The hex design looks like a Moroso cap. Maybe this one will work for you:

    https://www.summitracing.com/parts/m...0aAjYCEALw_wcB
    Mike
    Building the JaMFox N677JM
    Kitfox 5 Vixen
    KRNM

  4. #4
    Senior Member Dave S's Avatar
    Join Date
    Oct 2008
    Location
    St Paul, MN
    Posts
    1,833

    Default Re: Rotax 582 Radiator Cap WOES

    JustPlaneMike,

    Your photo of the original cap and and filler neck looks like what was the "standard" fitment for just about every car and tractor manufacturer of days gone by.

    Trying to go make-year-model is hopeless in my opinion.

    Should be plenty of caps out there if you can find a real auto parts store; and, I agree that Summit should have a cap which fits and is the right pressure rating - summit has about a huge variety of caps. I needed one for another application which required a "zero-cap" just a cap and no pressure spring - Summit had one.
    Dave S
    Kitfox 7 Trigear (Flying since 2009)
    912ULS Warp Drive

    St Paul, MN

  5. #5

    Join Date
    Oct 2018
    Location
    Kitchener, Ontario
    Posts
    127

    Default Re: Rotax 582 Radiator Cap WOES

    Part number would sure be handy. I have the same Rad Cap on my Model IV with a Rotax 912 80HP. still haven't been able to find a match at the right PSI

  6. #6
    JustPlaneMike's Avatar
    Join Date
    Apr 2020
    Location
    Raleigh NC area
    Posts
    20

    Default Re: Rotax 582 Radiator Cap WOES

    Now someone is saying in another form
    The lower radiator pressure was for the early 582's with the non ceramic seal for the water/ rotary seal. Later (blue top) or modified greys are ok with higher pressure.""
    I've got a gray head but I don't know if it's been modified or not so now I don't know if I should stay with the lower pressure or go with the higher pressure radiator cap

  7. #7
    Senior Member 109JB's Avatar
    Join Date
    Mar 2019
    Location
    Morris, IL
    Posts
    484

    Default Re: Rotax 582 Radiator Cap WOES

    You want the 13 psi cap. The notion that a lower pressure cap is better for older engines because of the rotary valve seals is hogwash in my book. If it is leaking past those seals, whether they are ceramic or not, then you have to fix it, not cover it up with a lower psi cap than is called for. The current service manual says 13 psi to prevent water pump cavitation and it doesn't differentiate between gray or blue head.
    John Brannen
    Morris, IL
    Sonerai IIL (Single Seat)
    Kitfox 3/4 1050 - Rotax 582 (Back Flying and sold)
    Kitfox IV 1050 - Rotax 582 (sold)
    Kitfox IV 1200 Speedster - Rotax 912 UL (project)
    Piper Twin Comanche (Sold)
    Glasair 1 FT (Waiting to start)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •