Results 1 to 2 of 2

Thread: M90 set-up .....

  1. #1
    Junior SCH Member
    Join Date
    Jul 2013
    Location
    France / Swiss
    Posts
    2

    M90 set-up .....

    Hi everybody,

    I'm French and if I wrote something that you don't understand please let me know I will try to explain it differently. Thanks

    I have installed an Eaton M90 on an Audi cabriolet 2.3 (5 cylinder - 10 valves) - 1992. You can go on the French forum to see my installation: http://forum.web-automobile.com/80-9...t6641-180.html
    So the M90 is installed but now I've got big questions!!!!

    I explain the situation:

    So far the hose from the intercooler isn't connected to the air box. The engine start normally the M90 seems to work properly and the air gets out from the hose. (lots of air ...)
    Now when I connect the hose to the air box the K-jet (mechanic injection system from Bosch) adjusted the injection but 3 - 4 sec after, the pressure is so strong that it blew up the oil level rod up to 50 cm.

    1st question:
    Is it normal that the SC (Supercharger) increases the pressure from the crankcase so much?

    2nd question:
    What should I do? Because that happened when the engine were in idle (900 rpm) I can't imagine what will happen if the engine goes faster . All joints would be destroyed with the over-pressure . No?

    3rd question::
    If that is normal that the SC increase pressure in the crankcase what pressure should I expect in it?

    4th question:
    What should I do with the oil level rod? Should I block it or not? Can the oil from the crankcase get out from this tiny pipe? (5mm diam. 30cm high)

    Thanks' for your help.

  2. #2
    Senior SCH Member vinces427bb's Avatar
    Join Date
    Jul 2011
    Location
    Los Lunas, NM
    Posts
    222
    it sounds like the engines crankcase is being pressurized by the increase airflow/boost.
    possible the PVC-valve is hooked to your airbox also?? this could be allowing boost into the engine.
    your oil level dipstick blew out 50cm due to crankcase pressurization..
    do not cap the dipstick tube, you must stop the boost pressure from getting into crankcase.
    some boost pressure will bypass the piston rings, but this should not be this issue.
    problem is you need insure that the boost pressure only gets into the intake...
    another way boost pressure can go into the engine is past a bad intake gasket on a v-6/v-8 type of engine.
    your engine is an inline 5-cylinder ?? so that would not be an issue...
    so back to the pvc-valve, on non-boosted engines the crankcase vapors/fumes get feed back into the engine for emissions control...
    you may need to reroute this pvc-valve to the inlet side of the M90 to stop the crankcase overpressurization...
    or vent it to the outside air...

Posting Permissions

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