SOLENOIDS AND IGNITION
The factory solenoid positioning on the Primera P11 head won’t work in a rear-wheel-drive application. Off-the-shelf kits are available to move the twin solenoids to a more suitable location. Alternatively, the Primera P12 20V only runs a single solenoid. What this means is both the cams switch over at once, as opposed to the two switching separately like on the P11 head. Because the 20V head only has one solenoid, the solenoid mount is physically much smaller, and with minor modification will work in the factory position without the need for relocation.
Another problem you will run into with the P11 head is the ignition set-up. On a P11 head, a distributor sits next to the two solenoids. This, along with the two solenoids, won’t fit in-between the firewall and the head. To remedy this, a P12 CAS needs to be used along with S15 coil packs, or P12 coil packs (both are identical). If you go this route and choose to run these coil packs, you will need to have a P12 rocker cover to sit them in. If you can’t source a P12 rocker cover, you can run external coils with a lead running down to the spark plug. Another solution is to source an extended coil pack from the likes of Bosch or AEM. Depending on your application, you may need to shorten the CAS cover, or have a new case made to get it to fit.