I AM BUYING A 97 355 SPYDER PENDING THE OUTCOME OF A PPI & PRESSURE AND LEAKDOWN TEST. SINCE THIS IS MY FIRST FERRARI CAN ANYONE TELL ME WHAT ARE ACCEPTABLE NUMBERS FOR EACH CYLINDER ? SHOULD ANYTHING ELSE BE DONE BEFORE I PULL THE TRIGGER?
Compression numbers should be at or above 200 psi, and fall with 10% of each other. Leakdown should be single digits, with 10% max being better than say 14 or 15% which starts to be a concern (I would pass at that point). Higher leakdown, and it has needs. As an example, my compression/leakdown numbers were as follows 1997 355 spider with 27k miles at testing (now 36k miles) 1) 220/4% 2) 228/2% 3) 217/2 4) 212/1 5) 228/2 6) 228/2 7) 228/10 8) 223/1 Tech described the #7 cylinder with the 10% leakdown to be approx. 50/50 leak between cylinder rings and valves. Possibly from some carbon build up on the intake valves. Suggested running some top cylinder cleaner though to reduce the build up.
Search the archives for more information on 355's..there are plenty of threads with "buyer's tips" on what to look for..not worth rehashing here.
