Andzey

VTT Hub compatibility

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Hi guys!

I was about to swapping the head from my 1999 early RN to 2005 S60R. 

Accordingly I would delete the intake VTT and leave operational exhaust VVT.

There are some doubts with the VVT hub itself. The early version hub coming from my 1999 engine has back-spring therefore it is fully back rotated to max retarded position, while B5245T4 hubs rotate freely without any back-pressure.

Do you have any guess, how would my 1999 ECU and solenoid react on spring-less hub, or are there any success stories of swapping later (2004-07) RN VVT cams and hubs into earlier RN engines?

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I have a RN head on my 98 N engine. It has the VVT gear on the exhaust side with nothing driving it. It will work fine just be sure that the gear is at full forward lock when installed and to use the proper cam lock tool. You can leave VVT solenoid in place and oil flow will not go to the gear. 

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Sure, disabling works by only unplugging the solenoid. 

My worries are about S60R spring-less exhaust hub, how the early P80 ME7 would addapt it

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The spring makes no difference. In fact most RN heads ive seen had no spring in the vvt hub me7 included. Im not sure what determines what cars got a sprung hub and which didnt or why its even there but I think that may have been something done early on maybe 99-00. I know P80 C70's made around 04 dont have springs so you should be fine.

As long as the gear is fully clocked clockwise and cams are locked in on install it shouldn't matter. 

Edited by 242bleek

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I just dismantled both the spring and spring less hubs, must say all the components are identical. One just has a spring in one side, other doesn't.

The spring definitely helps keeping the hub in max retarded position.

Also it seems obviously that in order to reach some cam angle advancement, the oil pressure in a spring-ed hub must reach higher value due to overcome the spring force. 

I highly recommend checking the hubs for axial play. All my hubs had various wear, but I was able to interchange the guts until complected one nice hub without any play. 

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