RB20 and RB25 runners the same?

[lukevl]

Just wondering if the Rb20 and R25 lower intake manifold runners are the same?

Because the Rb25 ones dip down in the middle two for equal length. I was wondering if the RB20 ones were all in-plane to make it easier to cut down.

Thanks

[lukevl]

Someone has to have some RB20 runners lying around???

[blind_elk]

I think you will find they are slightly different.

I just fitted a RB25DET into my R32. A couple of things I noticed:

1. There is now more room between the manifold and the strut tower, for accessing things like the oil filter and fuel filter.

2. To remove the fuel rail, on the 25 you need to remove the throttle body, whereas on the 20 you don't.

[BlueRB240]

They are almost the same save for a few things. Like the port size, the 25 is bigger than the 20. And the manifold won't bolt up to the Rb20 head. I looked into seeing if I could mod the greddy Rb25 intakemanifold onto the Rb20 head. It wasn't worth it. Could have been done but I passed up that Idea and bought a intake manifold off some guy. it's on my Pics page.

[lukevl]

Oh crap so the RB20 and RB25 mating surfaces are different? Not good at all.

Anyone have any idea if the runners are parallel in the RB20 anyway?