Technical Information (MGB 3a)
11/06/01 VENTING PROBLEMS
NOTE: The ½ hose restrictor which, may or may not be supplied with your kit, allows for adequate breathing on a well sealed engine. For engines that have above average blow-by conditions, the 1/16 hole diameter can be enlarged to the following: 5/64 3/32 7/64 or 1/8. It should not be necessary to exceed 1/8.
Obviously, the larger the hole within the restrictor, the more chance of oil transfer to the induction system.
We recommend installing the hose restrictor with the original 1/16 diameter hole first, then monitoring for excessive blow-by conditions. These conditions will be manifested by oil being blown out of several locations on the engine. These locations can be the oil dipstick tube, the oil filler cap or even the charcoal cannister.
Sometimes, we find it necessary to inform customers that the only alternative to keeping the oil transfer out of the induction system is : direct the breather hose to a suitable catch tank, then direct a hose to the lower extremities of the vehicle. Directing the hose in this manner removes the offensive blow-by smell.