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PPI - compression/leakdown results
Got a 2 page fax from the mechanic doing a PPI for me on the 88 911 I'm considering for purchase. He'll go thru the fax with me tomorrow. In the meantime, here are the results of the compression & leakdown testing:
http://farm3.static.flickr.com/2270/...84819a90_m.jpg Leakdown #1 78/80 #2 76/80 #3 73/80 #4 74/80 #5 78/80 #6 79/80 It's all Greek to me! Well not totally. I did read up some on this, and to my noobie eyes, the compression looks to be in normal range (160ish) & range of values appears within 7 of each other (relying on Bruce Anderson's Porsche 911 Performance Handbook which says values should be 130-170psi and within 15 of each other). Leakdown - . In reading up on this I saw values in 100% format (100psi, 97 left, 3% leakdown value). Do I convert the above numbers to 100% scale & do the calculations from there? If so, I get 3, 5, 9, 8, 3, and 2%. If not - help? Tomorrow I'll talk with the mechanic & go thru the 2 page laundry list of items he noted in the PPI. It looks daunting, but most of it is cosmetic stuff that does not really concern me (I'm not looking for concours quality & am willing to compromise those finer points for $ value if the important things are solid). But there are some bigger items that I'll have to know more about, particularly how soon they must be repaired & estimated cost to repair. More tomorrow after I talk to the shop. |
If i was to take a guess the mechanic put 80 psi and recorded the numbers, meaning 1-7% leak.
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Greek to me too and I would agree with samsnead.
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Here are the percentage leakdown numbers based upon the figurs posted. Oh, and Kathy is correct in her reading of the information. 1. 97.5% 2. 95% 3. 9125% 4. 92.5% 5. 95% 6. .9875% Some say rule of thumb is to look for leakdown less than 10% across all cylinders. As we can see, this car meets that criteria. Kathycha, based upon what you posted, and without knowledge of the particulars of how the tests were conducted (hot / cold engine) I personally think you have some good numbers there. Still I would wait for the mechanic to fill you in on the details. P.S. What's the mileage on the car? These leakdown and compression #'s would be very good on 100K+ motor HTH |
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Will report back on the rest when I've talked with the mechanic (fingers crossed!) |
my new car!
Well I've gone and done it. I pick up the car next weekend. There is not enough room here for the number of !!!s I'm feeling at the moment.
Goofy video with a good dose of Porsche garage porn, and some pics of the car at the end HERE. Thanks to yall for entertaining my noobie questions and helping me work thru the process of buying at a distance. |
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OK I humbly agree with you, my bad |
Sure are quite a few Porsches there. Love the music, put together a great video. Car looks good. The mystery color of the car in question is Cosmic Cranberry. Welcome to the sickness.
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:) Congrats!!!! 88 is the best year!!!! :)
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