Got Leakdown Results - Meaning??

[larry47us]

Pelicans, need sage advice here.

I am looking at a 73 911E Targa with 98K miles on it. It has been sitting for about 6 months. The shop is just getting ready to build it up for me. This will be my first Porsche!! (Viper Green No Less). The car is Numbers Matching, the price with a full bare metal repaint is $12 - $14K.

Still need to have my PPI done, but the first step was a Compression Test and Leakdown Test. The shop gave me the following information after the test.

I got the results of a compression and leakdown. I will list cylinder, then compression psi, then leakdown %

1: 140psi 19%
2: 140psi 18%
3: 145psi 18%
4: 145psi 9%
5: 152psi 10%
6: 140psi 10%

I'm generally pretty happy with these. Compression is well within the range of what it should be. The first three leakdown numbers are a little high, but not that bad. I reinstalled the fuel injection pump yesterday. This was different than the one the prior owner had on the car. He had the injection pump adjusted to the intakes in a fashion not within specs. It was still in the right ballpark so it ran well. So with this different one on it, it was running really rich. What I do with these injection setups is start from scratch beginning with a dissassembly on the intakes and flushing of injectors (time consuming but I feel neccessary to know what's going on). Then I adjust throttle plates, linkages........That will all happen when I remove the engine shroud to detail the engine.

Anyway.......with the motor running rich there is a high amount of carbon deposits which can hold a valve open a little and cause higher leakdown numbers.

So now to the questions. The car has a bunch of mechanical upgrades, which I won't detail here, unless someone asks. There is light rust in three places that the shop will repair. I am confident in his coachwork. I want to make sure that the engine and MFI are in good shape, so I don't immediately need to pump money into it. Are these numbers OK? From my reading, it seems that the compression numbers are good. But the leakdown numbers on the first 3 cylinders bother me. But, they are inconsistent with the compression numbers.

Since the engine has been sitting, could this cause the higher numbers on those three cylinders? Does the fact that they are on cylinders 1, 2, and 3 mean anything? Is it possible that a stiff run at high rpm would "blow out the carbon" that is sitting there and bring the numbers down?

Do these numbers tell me that I should be prepared for some mechanical repairs? Is there some mechanical work that I should have the shop do NOW, as part of my purchase agreement?

As you can tell, my newbie-ness is showing. I am excited about this car, just don't want my emotions to take over, or to be scared away by something that maybe is within range, or within expectations.

Any help or suggestions appreciated.

larry