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venting

Posted: Sat Oct 30, 2004 9:21 am
by Willie
If the engine has a pipe from the rocker cover going straight into
the air filter (the outlet) then it should have a pipe of one sort or
another on one of the tappet chest covers(the inlet). For these
types the oil filler cap should be solid as there is not a great deal
of suction to the air filter to remove the fumes etc.(the hole in the
air filter inlet should only be about 1/8th of an inch). If the engine
has a pipe going straight to the carb it will come from the tappet
chest cover(it is now the OUTLET) so you have to have somewhere
as an INLET to let air in. This is achieved by having a combined
breather and oil filler cap.
A solid filler cap on the later carb breathing type would lead to
higher oil consumption. A 'filter' type cap on the air filter cars
would lessen the cleaning effect and allow fumes to escape from
the rocker cover.

Posted: Sat Oct 30, 2004 9:56 am
by Kevin
I prefer my soultion which copies the original valve chest shape breather.
But the problem with your method Alec is that not all 1275cc (same for 1098cc) engines have the mechanical pump opening on the block.

Posted: Sat Oct 30, 2004 10:10 am
by Alec
Hello Kevin,
fair enough, I was not aware of that.

Alec

Posted: Sat Oct 30, 2004 11:03 am
by jbennett
Thanks for the explanation Willie. My Morry has an inlet on the tappet chest cover and the outlet pipe from the rocker cover connects at a point between the air filter and the carb. The filler cap is the solid type. Not sure if this is the right mix of bits now.

breather

Posted: Sat Oct 30, 2004 3:50 pm
by Willie
BETWEEN the air filter and the carb?? With your set-up it should
go straight to the air filter housing, get sucked through the air filter
element and then in to the carb inlet. I dont know where it could
connect BETWEEN the filter and the carb unless your carb has an
inlet pipe on its body? Does your air filter have an inlet pipe on
it facing the rocker cover? Your solid oil filler cap is correct as you
already have an inlet(on the tappet cover).

Posted: Sun Oct 31, 2004 1:02 am
by jbennett
Willie, I don't have any inlet at all on the air filter. The inlet is on the elbow joint under the air filter, just above and adjacent to the spacer. Obviously engine fumes travel the short distance straight into the carb from here. I assumed this was a standard type of setup, but maybe wrong.

Posted: Sun Oct 31, 2004 1:47 am
by jbennett
Sorry, "...adjacent to spacer" should be "...adjacent to gasket" (think one thing, write another).

breather

Posted: Sun Oct 31, 2004 5:03 pm
by Willie
JBENNET....could you give me your complete engine number,and
what year is your 1098 car? You appear to have a mix of different
model fittings. Is your tappet chest breather a simple swans neck
pipe pointing downwards or a cylindrical fitting pointing upwards?

Posted: Mon Nov 01, 2004 4:57 am
by jbennett
engine number APJM-L-28292,
1957, 948cc.
The tappet chest breather is a swans neck type coming out of the front tappet cover and leads straight down with the end about level with the bottom of the sump.
Jono

breather

Posted: Mon Nov 01, 2004 6:42 pm
by Willie
Well, that clears up one thing!! I have been talking about a 1098cc
engine which you do not have! The 948cc engines had three
different types of air filter, the first was a huge oil bath type. the second
was the 'saucepan' type with the breather pipe from the rocker cover
connecting at the elbow of the manifold (as on your car). The final
type had the breather pipe connected to the air filter. You should
still have a solid oil filler cap.