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    1. 03-21-2019 05:29 PM #1
      Hey Vortexers-

      I'm new to the forum, first post actually. Have owned an 86 N/A Mk2 Diesel Golf for about 4 years. Driven daily. Love the Mk2. Recently acquired an 87 GTI w/ the 16v/ABA block hybrid, serpentine setup with the p/s and A/C deleted. When I went to look at the thing, the seller let me do a compression test as part of the pre-purchase. I talked him down on the price quite a bit afterwards as the pressure readings were inconsistent. I'm wondering if someone can clarify this for me, because while he said he had the swap done in a VW shop near Asheville, NC, he didn't have any paperwork or receipts saved. I was annoyed for sure, but he told me the 16v head has all new lifters, valves, and upgraded camshafts from Techtonics.

      Anyway my compression test specs were up near about 200 psi, except for cylinder 3, which was only at 165ish. I did a wet test, and it went up to near 200 psi, so I'm guess the rings are blown on that piston, but can anyone tell me why those readings are so high?? The ABA block was from a low miles 1996, so no forged pistons or squirters. No turbo.

      I guess I'm also trying to gauge how long I can just drive the damn thing before I need to start looking for another ABA block or re-ring the one I have, and also if the high compression is in any way unusual. I'm not an expert, obviously, but I'm excited for this project! Thanks in advance for any advice!!

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    3. Geriatric Member need_a_VR6's Avatar
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      03-22-2019 06:20 AM #2
      It is a bit high even for stock cams. It could just be the gauge you are using if its uncalibrated. Also if the cam timing is advanced (intake or both) it will lead to higher numbers.

      I agree that the 165 doesn’t seem good and that a leakdown check will help see if the issue is in the rings or valve seal.

      You can build an aba 16v with 9a, abf (or custom) pistons but I would think the op would have mentioned if the bottom wasn’t stock.
      Last edited by need_a_VR6; 03-22-2019 at 06:30 AM.
      -Paul
      1992 Corrado - ALL MOTOR Drag Project [email protected] and falling
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    4. 03-26-2019 01:08 PM #3
      Sorry for my delayed response here. The seller didn't inform me of advanced cam timing, but I guess it may be a possibility. I checked compression with two different testers and got nearly identical readings, so I think the 195-200 was accurate.

      He told me the ABA block had only minimal seals and gaskets replaced, so no rings or pistons apparently. Its a damned shame considering the low comp on that one cylinder. My problem now though lol.

      As far as performance goes, it's running great right now.... how long do you think I can go before I need to locate a new block or pull this one?

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    6. 03-27-2019 11:38 PM #4
      200 psi is great. You should look for a builder sooner than later. ABA are still plentiful and cheap.

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