Quote:
Originally Posted by boothkc
any ideas or perhaps better tube?
Kevin
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Sounds like a combination of slosh/surge/windage/crank ventilation. I have chased this on a couple of cars now and have only overcome the issue when there has been sufficient breathing area to adequately relieve crankcase pressure.
When I swapped my GTRA over to alloy heads & carb I welded in a -10 fitting into each rocker cover and vented these to to a 2 quart catch can with a filter on top. I also added an oil return line off the bottom of the catch can back to the sump (effectively making a closed loop return for oil carried to the catch can due to long distance racing I am doing).
This is working OK but I would put 2 x -12 breather lines in if I was doing this again, mainly to reduce the velocity within the breather lines. The catch can oil return works OK, but I am getting some oil dripping out of the catch tank filter during long races. I suspect this is due to oil being pushed from the sump and up catch can oil drain line, or due to the filter 'straining oil mist from the breathed air and then it drips out of the filter material.
I am also interested to know what sort of oil consumption other owners are experiencing with their 302 or 351 powered cars. Seems like mine uses around .5 of a quart per race hour or so (does not breath excessively or smoke). I need to account for this as next race I am targetting is 6 hours so this could be critical (i.e. we may need to top up oil at a fuel stop).