Timing cover seal (not gasket)
 

Looking at this photo, made it while changing the chain and sprockets, I started wondering.

https://cimg8.ibsrv.net/gimg/www.cor...b5ecfd36c.jpeg


How the hell that timing cover seal, the round one pressed in the cover, actually seals anything?

It’s diameter is larger than crankshaft’s end with the key protruding through it and I’m not convinced that the smaller sprocket is actually rubbing against from the inside beeing enough to seal everything oil tight.

Can anyone shine a bit of light to my confused mind?

Because it seals against the damper not the crankshaft.

Sorry, damper in this context is what exactly? (I’m not native English speaker)

-Edit-

You ment harmonic balancer. Ok, but seal is stationary, harmonic balancer is rotating. Wouldn’t friction destroy it in short time?

No as long as the engine has oil in it.

And before you put the damper/harmonic balancer back on, put a little oil on the sealing surface of the seal with your finger or on the shaft of the balancer where the seal will ride. You don't want to start the seal dry.

I just went to look at the harmonic balancer and eureka my brain just grew a cell, I figured it out.

Thanks for the tip for lubricating the seal. I’ll do that. I’m a big fan of ultra slick but I guess engine oil works good by default.