Mike,
the secret to oil leaks on these engines comes in two parts, and neither are
really secret!
One is to accept that they all leak oil to some extent, although it is
perfectly possible to get this down to just a very occasional drip off the
bottom of the engine back plate.
The second is to understand that oil is retained in the crankcase by running
at less than atmospheric pressure so that air is drawn in rather than oil
pushed out, at the seals. People do talk about having a vented crankcase but
it really is more than just a passive ventilation to the outside air. The
system requires an active extraction of air (gasses and oil vapour) from the
crankcase.
So, theck that you have a breather hose (extraction hose) connected to the
cylindrical device on the timing chain cover. In its simplest form this
hose goes to the inlet manifold so that the suction at the carbs draws fumes
from the engine. Various refinements of this were used, includig PSV valves
and different fittings for different markets.
If the car has been modified (Webers?) it may just be vented to the air, or
to an oil catch bottle. Neither of these provide a positive extraction
system but are OK if you can accept some leakage.
If extraction system is all OK then it may be that when it was rebuilt the
rear seal was wrongly fitted which will give you good reason to curse! It
is possible to refit it with the engine in place but it really needs to be
removed to do it properly.
Guy
----- Original Message -----
From "Mike & Karin" <mcheman1 at msn.com>
> Greetings. I"m a new subscriber to the list and I'm looking for
information
> on how to stop an oil leak I have on my '67 Sprite.
>
> The engine (1275) was recently rebuilt and I find I have a heavy oil leak
from
> the rear of the engine. I've been told that this engine does not have a
rear
> main seal and that you have to live with some oil leakage. I'm using
about 1
> quart every 200 miles and this seems excessive.
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