Newbie question: Learning HOW to use precision tools

[ard]

Hi,

I have searched the forums for this topic, but haven't found this discussed. This notwithstanding, if this matter has been covered, please feel free to redirect me to the appropriate thread. TIA

Perusing the _excellent_ boards here, I still remain (respectfully) doubtful of Wayne's contention that rebuilding a 911 motor is not overly difficult, even for the 1st-time DIY-er

My contention stems from the following. It seems to me that there are 3 critical variables in play for a successful rebuild that a first-time DIY-er must learn, simultaneously while doing the rebuild:

1) how to use the precision tools necessary to inspect and reassemble the engine components. I do not currently own any "precision" tools besides a caliper and a torque wrench. None of the tools I ever bought came with instructions. Perhaps that is different with tools like dial gauges? My point here is that such precise measurements seem to be needed in many places and that the error introduced by improperly using a precision tool could falsify the reading. I am sorry if I am not very specific here (maybe: check whether the valve guides have too much play?), So how does one learn how to use these tools correctly?

2) how to tell whether a part can be reused or not. Again, to the untrained eye / inexperienced person some critical items might escape notice. And again, Wayne's book has lots of pictures (as does this forum), so perhaps the biggest "harm" is that a novice might err on replacing more than is necessary.

3) how things fit together. By "how things fit together" I mean recognizing and understanding the small differences between some parts, how to properly put things back together (how much sealant and what kind, etc.) You get the point. Wayne's book is a great resource, but, probably in a testament to my lack of abstract thinking ability, I need the "touch-and-feel" to get the "I see now" effect.

I guess my bottom line is: "Is the risk inherent in learn-as-go [along the above 3 dimensions] real or a figment of my imagination".

For what it's worth, I have worked a reasonable amount on engines, but only on external components (change spark plugs, starters, water pumps, etc.) that had the following common characteristics:

* no significant dis/re-assembly required
* real "precision" not required (although thoroughness is always key)
* no need to decide on reuse vs. replace (either throw away or return as core deposit).

Thanks for reading this.

[naparsei]

Ard,
I'm with you on this. My issue is rather the $ involved if you blow it materially. I mean, it would be much less risky to rebuild almost any other marque's motor vs. a Porsche, given the high risk for errors.

[mwildt]

Hi,

Reading a metric caliper is pretty easy. I found an excellent web page that shows it better than I can explain, there is even a video.

http://phoenix.phys.clemson.edu/labs/cupol/vernier/
http://www.rit.edu/~vwlsps/VernierCaliper/caliper.html
http://www.phy.ntnu.edu.tw/java/ruler/vernier.html
http://members.shaw.ca/ron.blond/Vern.APPLET/
http://regentsprep.org/Regents/math/tools/vernier.htm

The first url is the best, since it'll show you the different uses of a caliper.

Now, as with any fine instrument you have to show them respect by not dropping them and not use them for things they are not intended for. Like loosening wheels lug nuts with the torque wrench. Use a breaker bar instead.

With a caliper wipe the measuring ends clean first and after you're done. Do more than one measurement so you're sure of the value. This also assures that you measure perpendicular with the jaws of the caliper to the object.

There is different types of torque wrenches.

- Click type
- Beam type
- and others

If the model you have is utilizing a spring then it's very important to reset the handle/spring before you store it between applications. They tend to get a memory and thereby beeing inaccurate, if left in a constant setting.

Other instruments that is useful from time to time is

- dial gauge
- micrometer
- and others

Michael

[jgparker]

You're obviously a meticulous person, so you should have no problem getting it right with time and patience. If you rush the measurements, you're sure to get inaccurate results, but take you time and retake the measurement over and over until you get consistent results. There is definitely skill involved, but it is in getting spot-on measurements quickly and consistently.

As far as parts evaluation, you can always leave that to your machine shop. Make sure you use a good one that specializes in 911 engines.

"The book" should be all you need to get the right parts put together in the right order. I have seen a lot of success stories on this board and no "I wish I never started" stories so far. Go for it.

Good luck,

JP

[Wayne 962]

Let's put it this way - I think it's much easier than installing a new floor that you bought at Home Depot. That involves custom cutting and manipulation of the tiles, etc.

Specifically, let me answer your questions:

1) It may be me, but a torque wrench is pretty much an easy tool to use, and I include instructions on the proper way to torque bolts up in the front of the book.

2) I agree with you 100% on this - that is why I specifically recommend that you send most of your parts off to an experienced Porsche machine shop, who will tell you what you need to replace and what you don't need to replace. The obvious stuff, I tell you in the book.

3) Books are two-dimensional. I think that once you start to tear down the engine, then you should be able to get an appreciation of how it goes back together. Taking pictures helps too!

-Wayne

[ChrisBennet]

One of the key things when measuring anything is being able to get consistent measurements. If you measure something 3 times and you get 3 different values you aren't really measuring it. Refine your technique until you get consistent results.
-Chris

Roger: "Chris, if you want to be consistent..."
Me: "But I am consistent, I miss half of them every time."
Roger: "Ok, if you want to get consistent hits Chris..."