On some cars bleed valves work very well, and are cheap.

I fitted a plastic fish tank bleed valve to my Volvo turbo estate. £1.89

Does the job perfectly.

Every application is different though, but as long as the w/g is sized well for the engine, then a simple bleed valve can be very good.

If people out there think they are shite and useless.....it must be because they dont understand how they should be used.