Cooling question

Home Forums MGTD Kit Cars VW Based Kits Cooling question

This topic contains 10 replies, has 9 voices, and was last updated by  lrh 1 year, 7 months ago.

Viewing 11 posts - 1 through 11 (of 11 total)
  • Author
  • #302262



    I have a FiberFab VW based TDr. The engine cover that holds the spare tire is cut out to almost the size of tire. Does this need cut out to help in engine cooling? I have a lot of openings around the engine that seems to be enough for cooling even if that opening is closed, but I want to make sure. I plan on changing the looks of my spare and I don’t want to be able to look through the slots in the VW wheel and see the engine. Thanks !!




    You want some air flow through there but don’t need all that much; the BCW has a couple little slits. Do make sure any “openings around the engine” are not around the tin that forms the “floor” of the engine bay. That barrier is what keeps the engine cool during summer traffic jams. If it’s not there—and a lot of kits are missing it—make it your first order of business to fab-up some gap-filling aluminum tins out of an old “Bridge Out” sign or similar. Then move on to the spare tire pretty-up.




    There is no doubt that edsnova suggests the “best” solution.  However, according to my local mechanic here in Las Vegas, it’s not totally necessary.  I have a FiberFab and do not have my engine compartment sealed like edsnova suggests.  I have not experienced temps over 210 (since I fixed an exhaust leak).  This, despite 100% stop and go driving for 20+ miles in 95+ heat.  Even with the exhaust leak over the summer I never got over 230, and my mechanic says 230 is nothing to worry about.  He points out that the sand rails in use here have the engine completely exposed and they don’t overheat out there in the desert when it’s 120 degrees.

    As I understand it, the important thing is just to keep the hot exhaust from getting sucked back into the engine compartment.  That’s what the sealing does that edsnova suggests.  I have a single-pipe exhaust with an extension; maybe that gets my exhaust far enough away that I’m not having a problem.  It also may very well depend on how often you get in traffic jams in hot weather.  Maybe I have just been lucky.  YMMV.

    As for seeing the engine through the slots in the spare tire … really?  Heck, my air cleaner extends up inside the wheel itself and yet it’s hardly visible.  Yeah, I can see it if I look for it but it’s dark in there and who really looks inside the slots of the spare wheel?  Most people don’t even realize that the engine is back there.  Seems like a lot of trouble for little gain.

    • This reply was modified 1 year, 7 months ago by  johnsimion.



    I discussed the cooling slots around the spare tire quite a bit ago with Paul and although the builder is instructed to do this in the assembly manual, it isn’t that necessary. And the reason for the slots is to let heat out not let cooling air in. I do not have the slots cut into mine.

    Allen Caron
    VW based 53MGTD - "MoneyPenny"
    "If one thing matters, everything matters" - from the book The Shack




    While on this topic, how difficult is it to install a temperature gauge? My LR has never had one, but I think it would be good to have. Thanks in advance.

    Amor Conquista Todo




    Installing a temp gauge was fairly straight forward to me. Mount the gauge, wire the gauge power and gauge light and then run the wire from the gauge to the temp sender on the engine which was probably the hardest part of the whole thing. My 02 cents worth.

    Allen Caron
    VW based 53MGTD - "MoneyPenny"
    "If one thing matters, everything matters" - from the book The Shack




    As noted above, my TDr flies in the face of the accepted VW engine bay practices.


    The primary purpose for sealing the engine compartment is to separate the hot end of the engine (the cylinders and  exhaust) from the cooler intake side of the engine.

    I have the engine cooling tin in place. But I made no attempts to seal the engine compartment. And the Classic Roadsters Ltd. assembly manual makes no mention of it.

    The engine cover does have a hole under the spare tire mount (approximately ten inches across). I’ve never tested aiflow, so can’t tell you if air flows in through that hole, or if hot air escapes.

    The Duchess engine compartment is probably three times the size of the Beetle. And is more open all the way round the engine (front and back). I think there is more than enough air flow. My engine builder said the same thing. He also said he has run many VW microbusses the same way.

    And not for nothing, there are a lot of dune buggies running around with no sealed engine compartment.


    Paul Mossberg
    1982 Classic Roadsters Ltd. Duchess (VW)
    2005 Intermeccanica Roadster

    If you own a TDr and are not in the Registry, please go to and register (you need to copy and paste the link)




    Thank all of you for your responses. The openings I have around the engine compartment are made by the way the body parts of the original kit fit together. I looked again and it seems that there is plenty of room for air circulation without the spare tire opening. Actually my car runs pretty cool, it takes it about three to four miles before the heat gauge even gets up to 180° and then it pretty much stays right around the 180° mark. Thanks again !!

    Paul…I am a registered member, can’t remember exactly, but I registered in the October to December 2015 timeframe.




    Hey All

    I haven’t chimed in for a while but I couldn’t resist. The Penny Marie is a Duchess also and I’ve never had a problem with heat. I’ve been on the freeway in 90 degree temps going fast and I think I got hotter “and more sunburned” than the car. She’s never overheated on me. I also have the big round hole behind the spare tire but no one has ever asked me about the slightly visible air cooler that sits behind the rim I figured that if the question ever came up I’d just tell them “SHHH! That’s the Flux Kapasator!”

    Your Village Idiot is back!





    🙂 Good one.

    1981 Fiberfab Factory built. 1974 VW donor 1600 cc motor, cream body with brown fenders, beige top.
    Gold carpets, golden interior.




    Heh-heh, yeah, or powered by a squirrel wheel. Sometimes seems like mine is anyway.

    I don’t think there’s spare wheel venting for mine, solid round panel inside, and the car did well during the summer on 90 degree days too. Oil temp showed up to 230 after 10’s of miles going 70 MPH, usually around 220 to 225 on the highway.

    Let idle about 10 minutes on a hot day (talking with someone, I was too stupid to switch off) and that was the only time I noticed the engine seemed sluggish until moving again a couple minutes. Oil temp was probably trying to go above 230 but I know it wasn’t excessive either, if the gauge is to be trusted at all.

Viewing 11 posts - 1 through 11 (of 11 total)

You must be logged in to reply to this topic.

Skip to toolbar