couple of questions during my first cambelt change

The 4 tubes are sniffer tubes. They are used to check the co output from each cylinder. There should be 4 more for the front bank.

 

Try a search on "110860" (which is the F part for replacing the tubes) for prior threads.

 

Quick answer is, they rarely sample exhaust gas that way any more..you pass Inspection with a larger sniffer at the tail pipe tips.

Color Tune plugs are another better way to tune your air/fuel ratio.....

You do need to make sure it attaches to the header or you will hear an exhaust leak, ahead of your muffler.

Are you sure there are not plugs in the header, and they simply left these tubes mounted instead of removal??
EDIT: After looking at your picture I see no plugs, maybe they are just loose.

 

If you are referring to the CV boots, these are also a 80's era 911. Around $5 for the Porsche, $40 for the Ferrari. Would recommend replacing them all.

 

+1.

Torn ones will be loosing grease.

That said, you would pull the whole axle, to work it, so maybe doing one side at a time would save labor and expense, if the other side remains OK.

 

First off, congratulations on doing your first cambelt change. I found if very satisfying work the first time I did a major service on my 328. Regarding the exhaust sampling tubes, I would recommend not leaving them in that condition (either repair or cap them off). If they spin freely as you describe then you likely have an exhaust leak which has several down stream effects. I'm not sure what version 328 you have but if it is equipped with Kjet w/ lambda then the Jetronic ECU will be fighting to maintain an appropriate AFR as a result of the O2 sensor seeing excess oxygen. Some time ago one of my exhaust sampling tubes on the front bank was compromised and I ended up removing the tubes and capping the ports off at the manifold with plugs (See Steve's post for the part#). Some day I hope to fabricate some replacement tubes for no reason other than to maintain the original look of the engine bay.

 

The convenience of the sniffer tubes is that you can get AFR and CO readings pre-cat which is the proper method. Probably more meaningful for carb cars but still very useful. Not to mention it isolates activity at a specific cylinder .

 

I think the isolation of the single cylinder part is really cool, I know that the experts like Dave Helms does it this way and I suspect Rifledriver has had those sniffer tubes opened up on a car or two on more than one occasion. When I installed my Fabspeed cat I welded in a second precat O2 sensor bung so that I could monitor AFR using a second wide band O2 sensor monitor. In particular, I use an LM-1 to set the AFR in open loop operation as well as monitor appropriate AFR regulation with the native O2 sensor in closed loop operation. Not as good as monitoring at the individual cylinders but allows for a good general assessment.
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If you are not going to time the cams it really doesn't matter. You can take off the oil cap on the rear cam cover and you should be able to see the timing mark on the rear bank intake cam. Line up that mark with the mark on the cam journal and then you can check to see how the marks on the flywheel line up. In any event, you can just lock the cams and as long as you don't rotate the crank or cams, removed the belts and put the new ones on in the same position. Mark both cam sprockets, drive pulley and old belts to show which tooth is engaged in with gap. Transfer marks to the new belts and install in same position.

 

Here's what it looked like on my flywheel (86' 328). There's a vertical line between the "PM" and the "14" which the pointer should be directed to.
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Your sniffer tubes are probably not just loose. The screw insert has likely disintegrated. On carb cars they were brass brake fitting and steel lines-not sure if yours is the same. If they have disintegrated you will have trouble getting them out so you can screw a cap in. It will be easier if you take the manifolds off the car. The rear ones can we welded shut on the car but unlikely the front ones on the car. Any leak is not allowing air in the combustion as it is down stream of the exhaust valve. The exhaust leak will give an improper exhaust reading if you are using an o2 sensor or other gas analyzer as well as cause for smog failure in many states.

The timing mark is darn near invisable. I make a big yellow and pink lines on the clutch for the different banks so I can see it. I also make corresponding marks on the balancer/cam cover which are much easier to see.