« Previous Entry | MAIN | Next Entry »
December 04, 2003
Duncan...
First choice: pick up the later timing case
cover and utilize the intended stock simple PCV system. It works very
well.
You see, the Series A motor has a scroll
(oil thrower) affair back by the main bearing which depends upon tight
metal
(block) clearances for "oil tightness". The
motor does not have a "regular" rear main oil seal, Duncan.
Without the stock PCV system, these motors have a real tendency to leak
oil
out of this area, most especially as they
build miles on the crankshaft.
The stock PCV system will draw out
crankcase PRESSURE along with crankcase gases, which will all but
prevent otherwise minimum leakage
from crankcase pressures as the motor
builds miles.
I personally don't introducing any more
oil into the combustion process than
is absolutely necessary as oil reduces
octanes. OTOH, a LITTLE "dampens" combustion temperatures a bit and acts
as an upper cylinder lubricant. So, in
consideration of the foregoing along with
no rear main bearing oil seal, the simple
PCV system is more a "good" than "bad"
thing, all factors considered, unless you
are running a higher than stock compression (highest octane available
required) "tuned" application and your
priority is "performance".
Second choice: run VERY well vented.
This means at least a 1/2" breather off
the valve cover and a 1" fabricated
"vent" off the hole in the crankcase
previously occupied by the mechanical
fuel pump (on "pre-electric" fuel pump
earlier versions of the Series A motor).
Run the valve cover and crankcase hoses
into a "catch can" (upper half) and another
hose (other side of upper half of can)
vertically to ground as a "vent" for the
catch can. Drainable catch cans are
available out of a Summit or Jeg's catalog. Or, you can fabricate same
from
a coffee can or old windshield washer
plastic bottle.
Remember, you can never "overvent"
a "vented" application. The more, the
merrier!! But, go the PCV system route
first if you have a choice. Ran one of these on a stock '67 MGB for
years....
nice, simple, effective system. "Works
good, lasts a long time"! :):)
Cap'n. Bob
'60 :{)
PilotRob@... 27243
Posted on December 4, 2003 12:45 AM
Posted to category(s) Braking System | Cooling System | Cylinder Head | Electrical System | Engine (external) | Engine (internal) | Exhaust System | Exterior | Fuel System | Gauges | Interior | Lubrication System | Miscellaneous | Restoration | Technical Info | Tuning
