Type 4 Engine Rebuild

Discussion in 'Mech Tech' started by james cunliffe, Nov 14, 2018.

  1. james cunliffe

    james cunliffe Supporter

    I've just had my type 4 engine rebuilt with new cylinder heads installed and when I came to fit the carb linkage cross bar it was 25mm too short.
    The manifold gasket on both the old head and on the new are the thick ones approx 12mm thick.
    Does anyone know if the new heads are wider than the old ones and would my problem be resolved if I just fitted 2mm gaskets.
     
  2. 77 Westy

    77 Westy Supporter

    There is something wrong somewhere, new heads are dimensionally the same as the originals and unless you have fuel injection there shouldn’t be thick gaskets at the head/manifold.

    Who rebuilt the engine?
     
  3. Is it still the standard Solex carbs?
     
  4. Flakey

    Flakey Supporter

    Pictures always help!
     
  5. DubCat

    DubCat Sponsor

    Aren't they that thick to help prevent the heat transferring to the carbs? I have these ready to fit too. @Flakey I found that without the phenolic thick gaskets, I could barely squeeze the hex bar in on minimum adjustment - this is with twin IDF40s. Maybe somebody chopped the bar down to fit originally.
     
  6. james cunliffe

    james cunliffe Supporter

    The engine before rebuild had the thick gaskets, original manifolds and twin solex carbs but was not fuel injection. I now understand that a fuel injection model does need the thick gasket.
    The rebuild was done by Aircooled Hut in Mansfield.
     
  7. james cunliffe

    james cunliffe Supporter

    original solex carbs and manifolds
     
  8. 77 Westy

    77 Westy Supporter

    I suppose you have the cup and spring in the end of the cross bar?
     
  9. 77 Westy

    77 Westy Supporter

    I don’t have them at all on my IDFs but phenolic spacers could be fitted between the carb and the manifold. The factory spacers are for fuel injection and are fitted between the manifold and head.
     
  10. ^whs^ I spent while scratching my head till I realised it had fallen out...

    Spacers between manifold and carb to stop carb heating up and let manifolds get warm to reduce icing... if you don't have them take the big ones out and make two sets is small ones from each


    Sent from my SM-G930F using Tapatalk
     
    77 Westy likes this.
  11. DubCat

    DubCat Sponsor

    Aren't they that thick to help prevent the heat transferring to the carbs? I have these ready to fit too. @Flakey I found that without the phenolic thick gaskets, I could barely squeeze the hex bar in on minimum adjustment - this is with twin IDF40s. Maybe somebody chopped the bar down to fit originally.
    So is there a disadvantage to putting the thick spacers inbetween manifold and head? I have phenolics between carb and manifold too. The thick ones that came in the gasket set to go between manifold and head would allow me to use the standard length hex bar so I thought it was a good solution - seems it would work for Flakey too. Is this a no-no?
     
  12. 77 Westy

    77 Westy Supporter

    With carbs you really want the manifold warm to reduce the possibility of icing but the carbs cool so fuel doesn’t boil when you shut the engine down, making restarts difficult.

    If you only use the bus in warm weather you’ll probably get away with phenolic spacers between the head and manifold but if it’s cold and wet icing could be a problem, especially if the manifolds are long. It would be better to sort out the cross bar so it fits correctly rather than put spacers in the manifold IMO.
     
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  13. DubCat

    DubCat Sponsor

    Cheers for that. All makes sense.
     
  14. james cunliffe

    james cunliffe Supporter

    P1040083.JPG P1040084.JPG

    Thanks for all the replies.
     
  15. 77 Westy

    77 Westy Supporter

    That looks normal and you shouldn’t need the phenolic spacers. Is the cup and spring in the end of the cross bar?

    That’s not a 009 distributor is it?
     
  16. mikedjames

    mikedjames Supporter

    The thick gaskets were there to solve boiling issues. Somewhere over on the Samba @zedders (aka zed999 pn the Samba) is fighting an engine where the non-stock cylinders are manufactured several mm too tall to allow for certain crank and conrod combinations where capacity is increased on a T4. The result is that he has maybe 8mm extra spacing between the heads, low compression , low peak RPM and a massive squish zone. But his engine is a 2.3L T4.
    To fix it the cylinders have to be machined shorter.

    I dont know if its worth checking with your builder that the deck height was set correctly.
    If it was set Ok then this will not be an issue.
     
  17. 77 Westy

    77 Westy Supporter

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