M20 Rocker cover Breather

[hannaconner]

I am now captain paranoid about making sure everything in my rebuilt engine is clean. I haven't stripped the old engine yet but will be using the head and ancillaries to go on my rebuilt short motor. The oil I drained from the old engine was nasty, looked like metallic paint, upon removing the sump it had lots of grey metallic sludge. I went out and bought a parts washer today so cleaning the head etc should be fairly straight forward.

How do I clean the inside of the rocker cover? there is a riveted plate that covers what I assume is the gauze which constitutes the breather. I'm imagining 38 years worth of oily deposits and accumulated combustion crud will be inside. I've rinsed it with parafin over and over but no matter how many times I do it there's always more crud coming out.

[uwbuurman]

Thats needs to be chemicaly cleaned. Industrial powerwasher or something like that,. I just brought one of mine to a engine overhaul company, they just toss it in the washingmachine with other engine components.

Dont sandblast it, it is almost impossible to get all the sand out, with all risks of engine damage if it gets in the oil.

[e21Keith]

I had the same issue. I tried every method I could think of, left it soaking in diesel for weeks but still that didn't clear it, gave it to the local engine rebuild company, they left it in their industrial parts washer for a week, still no success.

In the end I ground out the rivets and removed the cover. There is no gauze, its just a serpentine passage that zig-zags its way through the cover, there is no way to clean it effectively without removal. After cleaning I refitted the cover by drilling, tapping and stainless screws (with threadlock).