Oil in inlet chamber

[tr6999]

Ive just found oil in the air manifold chamber of my 1969 TR6 PI. The car runs fine,air breather is clear but there is a build up of oil in the inlet side. Any suggestions on where its comming from and why?

[GreenV8S]

It's common to connect the crank case breather outlet into the intake manifold to reduce emissions. The crank case gases contain oil mist, and can sometimes contain large amounts of oil if there is oil in the area of the breather outlet.

[tr6999]

Thanks for that greenv8. Is there any way of reducing this? IE could the crank breather outlet be passing more oil than designed?

[Pigeon]

Some breather outlets have a sort of trap thing on them, a chamber filled with wire mesh which is supposed to catch oil mist. Over time this gets clogged up with cack and becomes less effective. It's worth taking it off and giving it a good decackulate in a bucket of petrol.

The other thing that comes to mind is is the breather breathing more than it should... how's your compression?

[lowdrag]

You haven't mentioned oil consumption either. E types are the same and the breather is connected from the cylinder head to the air filter. It's never caused a problem as long as the usual air filter changes are followed.

[RW774]

Simple,pull the crankcase vent pipe off and run the engine with the vac side blanked off. if the vent pipe is chuffing like the flying Scotsman the engine is F----D, If not put it back and don`t worry about it.
The engine/ breather design goes back to the 50s.

[//j17]

Probably just coming back through the rocker cover breather.

Think the PI has this (can't quite picture the PI set-up in my head) but on the carb'ed versions of the Triumph 6 engine they go rocker cover -> T-piece -> each carb. There is a pressure balance pipe - either external or built in to the block (think only early Vitesse's had the external one) that equalises the pressure in the sump/rocker cover and this origonally vented to atmosphere (not environmentally friendly). Later this vented through a filter (expensive to build). The final system was to vent the gases back to the induction system, to be burnt and chucked out the back.

A little oil (think coating and maybe a drop in each tracked) is expected. If you have more in the inlet than the sump...maybe some pressurising issues (does the dip-stick pop up on it's own?).

If you want you can change it to vent to atmosphere via a small filter (K&N do them), but these always block over time - some report quite a short time.

The other option is to run a pipe from the rocker cover to a catch tank - either spend loads on a shiney alloy one...or knock something up in the shed.

[GreenV8S]

//j17 said:

If you want you can change it to vent to atmosphere via a small filter (K&N do them), but these always block over time - some report quite a short time.

Those small K&N filters are NOT designed to be used a breathers. They're inlet filters for PCV systems, designed to clean the air being drawn into the crank case. If you put one of those on the outlet, it's no surprise they clog up immediately.

[tr6999]

Nice comments fellas. Compression is fine and not burning mutch oil so I will look into the vent /filter option.

Thanks for the comments

[//j17]

Based on this pic (http://users.belgacom.net/TR_gallery2/TR6_PI_engine.jpg) the rocker breather vents from the rocker cover in to the inlet plenum via a small flame trap (hiding behind the centre throttle body vacume take-off pipe and front throttle body injector feed pipes).

Any oil in the plenum?