Uprated valve springs

What are the best uprated valve springs for 4efte?

Anyone here have experience using brian crower valve springs and retainers?

Good question.

Can depend on your 4efte power target / RPM and boost level.
> What I read is 7500 is safe for higher boost knock ( stock valve springs )
> Plug and play ecu go to 8000 but are for more stock stepup so I guess less boost and stock valve springs.

With a small capacity piston like 4efte power will come at with higher air flow /revs so 9000rpm would be attractive.

The question maybe for 9000 rpm and high boost what spring works well with minimum spring pressure? ( so you don't lose power at lower revs pushing a way too hard spring up and down )


Found this interesting > http://www.enginebuildermag.com/2010/01/performance-valve-springs-and-retainers/

If you use lighter titanium retainer, shim bucket and valve then stock valves will still do a great job.
I am not a fan of a stiff spring at all.

I use Cruise valve springs which I got from RHD Japan.

Whether your gonna be spinning the motor more then the factory rev limit or not, if your building up the cylinder head I would reccommend uprated valvesprings because there the weakest part of the valve train. Weak valvespring will limit the engines ability to make consistent hp at high rpm's.

If you go for the Brian crower's just check with them the specifications of the spring, mainly base spring pressure and at how much lift of the valve timing at which coil bind can happen.

You have me wondering is engine heat getting to the stock springs at high hp and higher revs on longer runs.
I read oil is basically cooling for the springs and I guess they can get weaker and potentially float with excessive heating?

I think heat would be a factor over time, but I think the springs also loose their like elasticity. The valves will then not seal on compression strokes especially at higher rpm and the motor will loose power.

Ok thanks, Spring life is the main issue to address then. Doing this from what I read can be tricky ie. the right springs in combination with other parts shims etc. eg. Some cars using lighter parts shifted valve float into a lower rev range while those using lighter valves had a good float reduction across the whole rev range.