34 replies to this topic

[PACINO]

Looks like a poor fitted or badly mullered rocker cover gasket to me

Cheers gazza82

[Spider]

 

I either remove the Oil Separator altogether and plug the timing cover or get a small bore timing cover that doesn't have it.

The one on the Flywheel Housing should well be enough. If you find it's not, then you have much bigger issues !

Look how the engine turned out. Oil oozes everywhere. It only has one breather, the one on top of the clutch cover. Do you think it's enough Spider?

 

 

Respectfully, when I look this over and also your other photo from the front, it really doesn't look like crankcase pressurisation that's doing this but leaky gaskets and likely seals too in some places.

[PACINO]

I was going to ask if the rocker cover has a breather on it because clearly there's something going on there with a leak isn't there
 
whether thats caused by pressure build up or what obviously no idea

I appreciate your opinion Stuart.

[PACINO]

I either remove the Oil Separator altogether and plug the timing cover or get a small bore timing cover that doesn't have it.

The one on the Flywheel Housing should well be enough. If you find it's not, then you have much bigger issues !

Look how the engine turned out. Oil oozes everywhere. It only has one breather, the one on top of the clutch cover. Do you think it's enough Spider?

 
Respectfully, when I look this over and also your other photo from the front, it really doesn't look like crankcase pressurisation that's doing this but leaky gaskets and likely seals too in some places.

Ok Spider, I appreciate you giving me your point of view. In a few days we will dismantle the engine, and we'll know what is happening there. Anyway, I'm going to add two more breathers.
* I can tell you that sometimes there is so much compression that the oil comes out through the thread of the spark plugs. I don't know why this happens.

[Bobbins]

If you have oil coming out via the spark plugs you likely have knackered piston rings …

[Lplus]

Many 998/1098 engines only had one breather from the tappet chest (eg my clubman estate) connected to the carb.  The clutch cover breather has a wide bore and if connected to the carb the vacuum should be enough to clear the crankcase unless the engine is worn out.   The second vent on the timing cover does ensure both ends of the engine are cleared of gasses but I doubt it reduces the internal pressure below that of the clutch cover vent. On the other hand venting the single outlet to air and fitting one of those little filters will increase crankcase pressure, particularly as oil vapour clogs it..  (personally I think that's the worst option)

 

As to the rocker cover gasket, I recently had one that oozed oil, even though it looked good.  Replacing it stopped the oozing completely.

[PACINO]

If you have oil coming out via the spark plugs you likely have knackered piston rings …

Thanks Bobbins! Yes, I've suspected for a long time that the piston rings are not good. They are Federal Mogull Pistons with 40 thousand kilometers. Now I'm going to fit Swiftune ones (+0'40).
Let's see if I have more luck and they last longer.

[PACINO]

Many 998/1098 engines only had one breather from the tappet chest (eg my clubman estate) connected to the carb.  The clutch cover breather has a wide bore and if connected to the carb the vacuum should be enough to clear the crankcase unless the engine is worn out.   The second vent on the timing cover does ensure both ends of the engine are cleared of gasses but I doubt it reduces the internal pressure below that of the clutch cover vent. On the other hand venting the single outlet to air and fitting one of those little filters will increase crankcase pressure, particularly as oil vapour clogs it..  (personally I think that's the worst option)
 
As to the rocker cover gasket, I recently had one that oozed oil, even though it looked good.  Replacing it stopped the oozing completely.

Magnificent explanation Lplus. Thanks a lot man. I tell you that I don't have the clutch cover breather connected to the carburetion. It has a rubber tube connected to the floor. I mean, it's not connected to anything.

As for the rocker cover gasket. It is a cork gasket that I place after cleaning both parts well, I even apply a thin layer of special high-temperature silicone from Würth and that is well sealed.

[Lplus]

 

Many 998/1098 engines only had one breather from the tappet chest (eg my clubman estate) connected to the carb.  The clutch cover breather has a wide bore and if connected to the carb the vacuum should be enough to clear the crankcase unless the engine is worn out.   The second vent on the timing cover does ensure both ends of the engine are cleared of gasses but I doubt it reduces the internal pressure below that of the clutch cover vent. On the other hand venting the single outlet to air and fitting one of those little filters will increase crankcase pressure, particularly as oil vapour clogs it..  (personally I think that's the worst option)
 
As to the rocker cover gasket, I recently had one that oozed oil, even though it looked good.  Replacing it stopped the oozing completely.

Magnificent explanation Lplus. Thanks a lot man. I tell you that I don't have the clutch cover breather connected to the carburetion. It has a rubber tube connected to the floor. I mean, it's not connected to anything.

As for the rocker cover gasket. It is a cork gasket that I place after cleaning both parts well, I even apply a thin layer of special high-temperature silicone from Würth and that is well sealed.

 

 

Venting to air without a filter is the halfway house.  There will still be a small pressure inside the crankcase.  I prefer the vent to carb with a breather cap setup, though that does require a carb(s) with crankcase breather port.

 

The gasket I found to be oozing was indeed cork, and carefully fitted.  The replacement was fitted the same way and didn't leak.  Make what you will of that.
 

[sonscar]

There is a figure for crankcase vacuum,measured with a manometer in the dipstick hole.I think your center exhaust port has been blowing badly.Steve..

[PACINO]

There is a figure for crankcase vacuum,measured with a manometer in the dipstick hole.I think your center exhaust port has been blowing badly.Steve..

Thanks Steve. Yes, I think there was some problem in the center of the exhaust manifold seeing that blank mark on the back. Possibly, it was poorly tightened to the cylinder head.
Could you tell me where that dipstick hole is?

Kind regards
Luis

[sonscar]

Where the dipstick fits a Leyland special tool measured the crankcase pressure.Ages since I saw it and my ageing memory fails,Steve..

[Lplus]

 

There is a figure for crankcase vacuum,measured with a manometer in the dipstick hole.I think your center exhaust port has been blowing badly.Steve..

Thanks Steve. Yes, I think there was some problem in the center of the exhaust manifold seeing that blank mark on the back. Possibly, it was poorly tightened to the cylinder head.
Could you tell me where that dipstick hole is?

Kind regards
Luis

 

You need to check the manifold flanges for the inlet and exhaust are the same thickness, unless you are using a combined manifold.

[PACINO]

Where the dipstick fits a Leyland special tool measured the crankcase pressure.Ages since I saw it and my ageing memory fails,Steve..

The oil dipstick Steve ?

[PACINO]

There is a figure for crankcase vacuum,measured with a manometer in the dipstick hole.I think your center exhaust port has been blowing badly.Steve..

Thanks Steve. Yes, I think there was some problem in the center of the exhaust manifold seeing that blank mark on the back. Possibly, it was poorly tightened to the cylinder head.
Could you tell me where that dipstick hole is?

Kind regards
Luis

You need to check the manifold flanges for the inlet and exhaust are the same thickness, unless you are using a combined manifold.

The truth is that the exhaust and intake manifold are independent and made of different materials, but if they are well tightened to the cylinder head, there should not be any leaks.