911 SC tune-up questions and loose distributor shaft
 

When I got my car (an '81 SC w/ 159,000 miles)a bit over a year and a half ago, I dropped the engine to do major clean-up and fix the oil leaks. Before I put it back in, I adjusted the valves and put in new plugs along with all the other extra tune-up stuff. Now, 17,000 miles later, the cars started running poorly, so I figured time for another tune. Boy, now valve adjustment and plugs are a completely different story! Also, when I was replacing the rotor, I noticed the distributor shaft can be wobbled all over the place, possibly giving me the noticed loss of power. So I have two questions:

1) I looked here for threads on replacing the distributor shaft bushing/bearing and have found nothing and no parts offered on Pelican. Has anyone done this? The new distributor is $$$$$. I'm confident I can find a used one, but if the replacement bushing is available and the distributor can be rebuilt, why not?

2) Playing around with several plug sockets and numerous extension and universals all taped together, I can start removing plugs. Unlike other cars where after a turn or two when the compression on the gasket is relieved the plug unscrews quite easily, there is significant resistance still noted. I chickened out on removal after a few turns fearing my in ability to get a new plug back in. Is this normal? Is it just carbon build up on the tip of the plug? I tried removing a second plug with the same result.

So I'm looking for the experience of all of you other guys out there. This board has been a tremendous help so far with all the things I've done.

Thanks in advance!!

Can't tell you anything about #1, but:

It can be dangerous removing the plugs since the heads are aluminum. If they have been put in too tightly and not coated with antisieze and left in too long, they can take the threads from the heads with them when they come out.

I would loosen them a bit, then try to get some lubricating oil in there and let it soak for awhile. Alternately loosen and tighten the plug until it seems to move more freely and slowly work your way upwards with this strategy.

Always coat the threaded portion of the plug liberally with antisieze compound when reinstalling, being careful not to foul the electrode with it.

Good luck,

ianc

jbaeng,

here is a link to when I rebuilt my distributor, I do not have time at present to discuss, but this link might help.
http://forums.pelicanparts.com/showthread.php?s=&threadid=181925&highlight=DIY+di stributor

This is the combination of tools I use for spark plug removal/installation(1/4" drive ratchet):

First: http://buy1.snapon.com/catalog/item.asp?item_ID=107&group_ID=112

Second, the smallest of these, which are great BTW: http://www.sears.com/sr/javasr/product.do?BV_UseBVCookie=Yes&vertical=TOOL&pid=00 943355000&subcat=Socket+Accessories

Third: http://buy1.snapon.com/catalog/item.asp?P65=&tool=all&item_ID=67019&group_ID=1150 2&store=snapon-store&dir=catalog

Sometimes you can use this too, but usually 3 & 6 have clearance issues... http://buy1.snapon.com/catalog/item.asp?P65=&tool=all&item_ID=851&group_ID=110&st ore=snapon-store&dir=catalog

Always use anti-seize, as mentioned by the others...always, always, always...ALWAYS!!!

In Wayne's 101 book, Project 22, it states, I paraphrase," Never use antiseize compound on the spark plugs."

Any comments?

When using dissimilar metals with threaded fasteners, it is always recommended to use an antisieze compound to avoid galling. The factory recommends using it with the steel stud\Aluminum lug nut combo.

Don't know why Wayne would recommend against it.

Don't use it if you don't want to. ;)

ianc

I know I use it for anything that has to be bolted onto the engine that may have to come back off again in the future, i.e. spark plugs, intake manifolds, heat exchangers...pretty mauch anything but the flywheel bolts...

Thanks to all for the great info so far, keep it coming!!!!

By the way, I looked at the informative thread about rebuilding the distributor. The main question is does anyone have a source for the bearing? If need be I can get one machined, but I'd prefer having a source.

Another question, if I pull off the valve covers to adjust the valves, will plug changing be easier with more access and clearance?

I believe Wayne mentions something about heat transfer if you use antisieze. I use a coper based anitsieze on my BMW to improve conductivity (as recommended). I have not had occasion to use it on the 911...

I've removed my A/C system, backdated the exhaust system and backdated the heating air system, so all plugs and valves are readily accessible.

The factory spark plug tool is the one to use. I do not use antiseize on spark plugs, but I also do not install them too tight. When the crush washers are finished crushing, the plug is in tight enough. In fact, when the crush washers begin to crush, you are probably at about the 18-20 lb/ft spec already.

You can find bushings of any size and type. Industrial supply houses, various other sources. They can be had. Be very careful with the Hall Sender unit, though replacements are also available, at NAPA of all places!

I use NGK plugs. or Bosch.

Be sure the distributor body is fully seated against the engine case. Still, if there is wobbliness, the bushings need to be replaced.

Never change your spark plugs until after you've adjusted your valves. A piece of carbon or other debris could become lodged between the valve and seat and affect the accuracy of your measurement.

That being said, I guess there's no reason why you shouldn't be able to change the plugs with the valve covers off..

I only use copper-based anti-seize.

jbaeng,

Yes, you will get better access to the plugs if you remove the upper valve covers. Not by much though, they are still down a few inches through the cam tower. You may find it easier to put oil down there with them off and there is no real reason not to take them off first if you are planning a valve adjust anway. Any local machine shop should be able to machine a bearing for you given the appropriate stock, but the question is, what are the correct dimensions to machine it to, and what part number should be used for stock?
This is one of those things that I agree with 100% in theory, but in practice never do. ;)

ianc

I beleive that some anti seize compound can affect the grounding or earthing of the spark plug and I think that is what Wayne is getting at in his book.
Coppercote is the type we use at work when a good earth is required in the electrical buisness.