Crank case vent . . .

Discussion in 'Technical' started by mashori, Sep 4, 2010.

  1. mashori

    mashori Member

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    My crank case vent is this rubber grommet that sits on top of my passenger side valve covers. Inside it is some sort of filter thing that pushes into the grommet. A hose goes from that to the carb. How do you guys have your crank case vents hooked up?
     
  2. yellow75

    yellow75 MCCI Oregon State Rep Supporting Member

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    The little filter thing should be the pcv valve and is usually at the rear of passenger side valve cover, should have another on driverside that goes into the base of air cleaner, in theory the one on the passenger side take care of venting at lower rpm and when rpm increases there is less vacuum at that location and at higher rpm the one in the driverside has more vacuum as the carb creates a stronger vacuum at higher rpm.

    The pcv valve is essentially a controlled vacuum leak as it opens slightly as demand calls for it

    There is an age old debate as to all the different methods used to evac the crankcase pressure, bottom line is you need some kind of system or oil consumption will be higher and oil will get dirtier faster.

    Some people just use breathers that are open to the atmoshere and not hooked to engine vacuum one on each valve cover, some people use one breather open to the atmosphere and one pcv to under carb base and some use use a closed system with a cap/plug that does not allow air to enter the motor on one cover and pcv valve to under carb base
     
  3. mashori

    mashori Member

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    I do have one on the driver's side too, it appears to have a filter material only and it doesn't have a hose running to anything.

    the passenger side grommet is leaking so I definitely going to replace the grommet. I have a leak around the PCV hose so I'm sure that's not helping my carb trouble.
     
  4. Bryant

    Bryant forgot more than learned

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    i should have some grommits laying around.
     
  5. yellow75

    yellow75 MCCI Oregon State Rep Supporting Member

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    Yes get the pcv valve grommet issue fixed and I am sure that will help, also make sure your pcv valve itself is good, it should rattle but I really dont know the best way to check it. Upon research I have done it is said that the quality of the cheaper pcv valves is not real good so get a good brand if you opt to replace it.

    As for your driverside, you probably dont have the stock air cleaner so you would not have anyplace for a hose to run to but if you could create a spot to put a hose to the side of the air cleaner that is ahead of the air filter (so the air is drawn through filter) it would be beneficial IMO.

    Not sure if this will help your carb problem as you could take the pcv valve completely out of the valve cover and as long as it is hooked up it should still run, but if you unhook the hose from the pcv valve then it will run very bad as you have created a huge vacuum leak
     

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