SBC Rocker cover Oil leak

[RobP]

Hi. I am no expert but my understanding is the valve vents the gasses to relieve the pressure, but I would assume there is some small amount of oil vented along with the gas. I don't think it hangs on to the oil.

[chris27_blue]

Hi Incey1966

Do you have breathers on the rockers, or are they being vented to the carb.

May be an issue with to much pressure build up from the engine gasses. I had the same issue so I eventually bought one of these PCV valves https://mewagner.com/. I is excellent and I no have no oil leaks from my rockers.

Regards

Rob

Just swapped out my breathers as a little bit of oil escaping making a slight mess

Have thought about a PCV system, but seems a lot of hassle for a bit of oil misting- altho very ECO considerate

How do these valves work, do we know? Does the valve just vent gases and hang on to the oil, then drip feed it back through when engine cools?

[incey1966]

All good suggestions so far.
Worth looking to see if the rocker covers are cast or pressed. The pressed ones can distort along the seal, and consequently weep oil. I bought cast ally covers, fel-pro gaskets, and pcv and now all good. Another thing to check is that its not the inlet manifold, they can leak through the mounting bolts and pool on the cylinder head, worth using an rtv on the bolts.

They are pressed steel covers which I think may be the problem. I'm pretty sure the oil is coming up the threads of the rocker cover bolts as there is oil visible on top of the rocker cover flange.
I did think about going for cast Ali covers.. Might have to go on the xmas pressie list....

[gaxor]

All good suggestions so far.
Worth looking to see if the rocker covers are cast or pressed. The pressed ones can distort along the seal, and consequently weep oil. I bought cast ally covers, fel-pro gaskets, and pcv and now all good. Another thing to check is that its not the inlet manifold, they can leak through the mounting bolts and pool on the cylinder head, worth using an rtv on the bolts.

[RobP]

Hi.
Bought direct from mewagner.
Rob

[Dek]

Are the heads steel or ali?

[Dek]

Hi Incey1966

Do you have breathers on the rockers, or are they being vented to the carb.

May be an issue with to much pressure build up from the engine gasses. I had the same issue so I eventually bought one of these PCV valves https://mewagner.com/. I is excellent and I no have no oil leaks from my rockers.

Regards

Rob

Interesting. That's putting some science on the problem. Did you buy direct from Mewagner or is there a U.K. stockist?

[CobraPaul]

I have an oil leak on SBC on from both rocker covers, the RHS one being the worst.
It appeared to be coming out of the holes where the clamps hold the covers down.
I had bog standard gaskets so I bought a couple of the steel frame Moroso jobs with compression limiters etc and fitted these thinking it would solve the problem.
It didn't I'm still getting oil weeping out.
Anyone had similar issues ??

Are they the right gaskets for your heads? From what I've read there are many different fittings.
I need some new gaskets as I need to take my rocker covers off soon. But trying to find which gaskets to buy first. 

[RobP]

Hi

This is the same set up as mine (please see pics attached), the mewagner PCV valve outlet goes straight to the bas of the Holley Sniper EFI (basically same as a 4 barrel carb base). The other side just has a breather. Once I setup the PCV valve according the the instructions supplied I never had any issues with leaks since.

Regards

Rob

[incey1966]

Hi Rob,

I have a PCV valve on the LH rocker connected to the carb and I have a breather on the RHS.
The only other job I was going to do was to replace the breather with a vent to the air cleaner.
Not sure this will help with the oil leak though.

[RobP]

Hi Incey1966

Do you have breathers on the rockers, or are they being vented to the carb.

May be an issue with to much pressure build up from the engine gasses. I had the same issue so I eventually bought one of these PCV valves https://mewagner.com/. I is excellent and I no have no oil leaks from my rockers.

Regards

Rob

[incey1966]

I have an oil leak on SBC on from both rocker covers, the RHS one being the worst.
It appeared to be coming out of the holes where the clamps hold the covers down.
I had bog standard gaskets so I bought a couple of the steel frame Moroso jobs with compression limiters etc and fitted these thinking it would solve the problem.
It didn't I'm still getting oil weeping out.
Anyone had similar issues ??