Rb26 Gtr Valve Springs In Rb25 Head

[zac the muss]

just a quick question, is it possible to drop rb26 valve springs into an a r33 rb25de head?

I've done a bit of searching but haven't been able find a definite answer. the plan is to stay with the standard DE cams for now.

also is there any sort of quick check to determine the condition of the springs?

cheers

[zac the muss]

anyone have an answer to this?

[gtr jet]

No idea if they'll fit but you need a spring compression tester to check if they're still in good nick.

[WMDC35]

Springs are different

[nicksamaniac]

I can answer this,

Yes they do fit, they are the same physical dimensions od, id, and length.

They do however have a higher seat pressure, obviously why you fit them to a de head!

I have a rb30det using a r32 rb25de head with rb26 springs fitted, still under the de cams, which are far less aggressive in lift then 26 cams.

Far as I can research the de springs will only hold up to about 15-16psi of boost before unseating the valves at high rpm causing valve float.