NB8A Engine (head) Question

JBT · Postby **JBT** » Thu Sep 20, 2007 10:15 am

Does the NB8A engine have a CAS at the rear of the exhaust cam and associated \"O\" ring oil seal as per the NA8 :?:

The parts diagram I have indicates there is just an oil seal cap there. It's not a good diagram though.

rhysk · Postby **rhysk** » Thu Sep 20, 2007 10:46 am

No, it is at the front.

Bevan · Postby **Bevan** » Thu Sep 20, 2007 10:52 am

rhysk wrote:No, it is at the front.

Bevan · Postby **Bevan** » Thu Sep 20, 2007 11:00 am

Crankshaft Position Sensor is number 6.

JBT · Postby **JBT** » Thu Sep 20, 2007 11:02 am

Thanks. Yes, I know about the CPS at the front, my question is what is at the rear of the exhaust cam :?:

Is it just a blanking seal :?:

Photo anyone :?:

Matty · Postby **Matty** » Thu Sep 20, 2007 11:14 am

JBT wrote:Thanks. Yes, I know about the CPS at the front, my question is what is at the rear of the exhaust cam Is it just a blanking seal

There is a blanking plate. You need to remove the last cam cap to remove it. Not sure if there's an o-ring on it, but a CAS will fit in, so probably... The cam still has the dog drive for a CAS too.
photo on page 46

Bevan · Postby **Bevan** » Thu Sep 20, 2007 11:32 am

JBT wrote:Thanks. Yes, I know about the CPS at the front, my question is what is at the rear of the exhaust cam Is it just a blanking seal Photo anyone

OOoooh, sorry, I know what you'r asking now. Matty is right, there is a blanking plate there. You can retrofit an NA8 CAS into that spot. This way, you can disconnect the VVT part of the engine and control engine timing with a piggy back that doesn't know how to control the MX5's VVT.

That's how I learnt what is in that spot anyway.