Zenon, hey? Unh, mmm, that's an unusual name. But then, so is Seldom Seen Slim, so have at it.
Yes, there is a way to offer stuff for sale on landracing.com. On the home page of the Forum (not the home page of the site, but the page you get when you first-thing click "LSR Forums") you should scroll down a ways. You'll find there two for sale categories. "For sale by private parties" is for racers trying to sell a this or a that that they've acquired and don't need anymore, for instance. Low volume, not in it to make profits, but rather to clean out the shop and hopefully generate a bit of cash.
The other for sale category is "For sale by small business" -- and that's where I expect your listings ought to go. I assume from your post that you've got a quantity of timing covers and water pumps and whatever else that you'd like to sell -- for enough to get your investment back and maybe more, maybe a big bunch more. For sale by small business ads do require you to pay the site a bit for the privilege of listing there. Contact me for further details and the cost. I'll give you this hint -- it isn't much.
Welcome to the land of land speed racing, Zenon.