Double valve springs C20xe/Let

[Boets]

Hi

Can anyone recommend me some double valve springs with steel caps(retainers) and platforms(13 mm coscast) for the c20xe/let engine??
In use with hydraulic followers!!

Thanks

 

[BladeSTX]

For sure the XE tuners have something suitable for your application. (Risse, SBD, etc)

I only know that for LET (exhaust) springs, things are a bit different as you need sufficient closing force to oppose the high exh. manifold pressure. Standard springs have a weak closing pressure( or can become weak by excessive headwork) and this causes valve flutter on high boost.
Some people use thin washers under the springs, but better use the later 642244 spring, which are a bit longer and have higher closing force.