21 replies to this topic

[PACINO]

Hi folks! Pretty much since I rebuilt the engine (1971 MG 1300 S) in 2004, it has always been smeared with oil. On the ground it DON'T throw a single drop, but every time I go to pass the annual inspection (MOT) on the paper they give me it says: "oil oozes". You look at it from below and it is all stained with oil; the carter, transmission, block from behind. in front... I think it is due to the compression of the engine and the lack of breath or ventilation. I haven't breather in the timing cover or in the rocker cover, and I don't PCV valve either. It only has the breather next to the clutch cover and the oil filler cap.

I'm going to remove the engine to rebuid it very soon and I don't want this issue any longer. What can I do to stop it from leaking oil everywhere?

Thanks in advance!

[nicklouse]

Get some UV dye for your oil. Then you can see where the problem is coming from.

[unburntfuelinthemorning]

And fit more breathers.

[Spider]

How have you currently got your crankcase breather plumbed ?

[PACINO]

Thank you guys!

[PACINO]

How have you currently got your crankcase breather plumbed ?

Hi Spider. I've always had an one meter long tube connected to the chimney next to the clutch facing down. I mean, it's not connected to anything. It is fastened with a tie to the power cable that comes from the battery, so that the smell goes down and does not enter the vehicle.

[PACINO]

[MiniMadRacer]

On the race motor where we are allowed we vented the breather to the atmosphere rather than the carb, as we didnt want to reduce the power of the inlet charge with oil contamenants, so I do not see that as a problem so long as the breather isnt blocked.

 

Is the dipstick a good fit in the hole?

[MiniMadRacer]

And check the rocker cover cork gasket for a nice tight fit with the rocker cover not bent or warped, tin ones do warp if over tightened

[PACINO]

And check the rocker cover cork gasket for a nice tight fit with the rocker cover not bent or warped, tin ones do warp if over tightened

No, the rubber tube coming out next to the clutch is not stuck or blocked. From time to time I put air under pressure to push down the mayonnaise that accumulates.
As for the oil dipstick, it fits perfectly. And the rockers cover does not leak due to the cork joint.
Precisely because everything is perfectly sealed, the oil finds its way elsewhere due to engine compression, oozing out of "all" the joints of the block.

Regards

[Spider]

 

 

Thanks for the photo, that helps.

As you don't have CCV Ports on the Carbs, I'd suggest connecting the Crankcase Breather tube to a PCV Valve, then to a T piece to the Brake Booster Hose, on the Manifold side of the Non-return Valve.

 

A after-market replacement type PCV Valve with 13 mm fittings for a small car would be fine.

I'd be sure the open breather has a lot to do with your 'oil smear' if there's no visible leaks from the engine / gearbox.
 

[PACINO]

Thanks a lot Spider. Yes, I already have my eye on the PCV valve that PL Minis sells. Second-hand used ones are as expensive as new.
I have seen this that someone made by hand and this other one that they sell in the USA. I'm fine with either one. I think it may help the engine sweat so much oil all over the place.

[Spider]

Actually, I wasn't meaning the Breather Take Offs and Oil Separators. The only you have on the Flywheel cover should be well enough - unless your rings are worn.

I was actually referring to a Valve that goes between the Oil Separator and the Inlet Manifold, like this;-

 

 

This will not only remove fumes from the engine bay, but also slightly lower the crankcase internal pressure compared to the atmosphere, I think it would likely go some way to solving your issue here.

There's a good description of the PCV (and CCV) Systems here, they do much much more than you realise, including removing moisture (that leads to acid formation) from the oil. I firmly believe all road cars should have these systems;-

https://en.wikipedia...tilation_system

 

[PACINO]

Cheers Spider. Yes, I had seen that link and this other one (http://www.agcoauto....2_articleid/197) that you put in an old thread that I have consulted these last days about the crankcase ventilation and the PCV valve. But tell me, what did you put there that is a 'non-return' valve? With that, I don't need to bvy the PCV? I imagine that it goes adapted between the hose that comes from the outlet next to the clutch and goes to the tube that joins both Hs2 carburettors. Is it so?

[Spider]

Cheers Spider. Yes, I had seen that link and this other one (http://www.agcoauto....2_articleid/197) that you put in an old thread that I have consulted these last days about the crankcase ventilation and the PCV valve. But tell me, what did you put there that is a 'non-return' valve? With that, I don't need to bvy the PCV? I imagine that it goes adapted between the hose that comes from the outlet next to the clutch and goes to the tube that joins both Hs2 carburettors. Is it so?

 

The PCV Valve is more than a non-return valve, it regulates the flow rate too.

 

Before I forget, it you haven't already got one fitted, you'll need a Vented Oil Filler Cap.

The PCV system connects direct to the Manifold, not the carbs.

 

The diagram you've put up here is a different system again, that's a CCV System, which is better again than PCV, however, from what I could see of your carns, it didn't look like they have the CCV Ports on them, hence why I suggested the PCV set up.