RB20/25/26 Valvetrain

[Chigga311]

Does anyone know if any of the parts in the RB20 Head are compatible with anything else.

From what I've seen on Tomei web-site it looks like the Z32 VG30DE/TT and the RB20DE/T share the same Valve Springs

And the Valve guides for the Intake are the same RB20,25, and 26

Valve guides for the Exhaust are only the same with RB20,253

The Valve lifters seem to be the same with the RB20,25 and VG30DE/TT

According to JUN the Valve spring retainers are the same for the RB20 and the VG30DE/TT

This is not Head related but the Crank Bearing Cap Studs are the same RB20,25,&26

-So today i took my head down to the machine shop and he took a look at it and said that it doesn't seem like any of the valves were seating. LOTS of build up on my valves nasty nasty crap all over them

So if anyone has vavle seats or knows of USDM seats that are the same please let me know thanks

[Chigga311]

Nobody knows anything about the RB20/25/or 26 valvetrain????

[Roy]

What engine is it you have?

[Chigga311]

I have a HCR32 Gts-t RB20DET

Im trying to rebuild the whole motor right now

from the top to the bottom

[Sydneykid]

What I can tell you about RB valve train;

The RB20DET valves are not the same as any other RB. The combustion chambers are too small for RB25/26 sized valves.

The RB26DETT valve train has solid followers, RB20& RB25 have hydraulics. So you can't use bit out of one in the other. You have to swap the whole lot over. This is of no use to you as the valves won't fit anyway.

You can use RB26DETT valve springs in an RB20DET but you have to modify the spring seats in the cylinder head and the retainers. You also have to use shims to achieve the right seat pressure.

We always use genuine Nissan valve seat inserts, the part numbers are on FAST.

We find it is cheaper to throw bad RB20DET cylinder heads away and start with a good one. It is cheaper to buy a good used cylinder head and refurbish it, than buying the new parts from Nissan and then spending hours on it.

Hope that is of some small help:cheers: