Hi guys, was wondering if anyone has the specs for the L28; I have the Haynes manual for the L24/L26 but the supplement chapter doesn't contain much info on the L28. I was after the wear limit for the compression rings. I'm not sure if it's the same as the L24/L26.... The rings have done a hard 20,000km's......I can't remember the gap that I measured, I took the measurement a while back and forgot to chase it up. If anyone could help or lead me on the right track, that would be great!

The specs are the same across the board. Frank Honsowetz (How to Modify Your Nissan & Datsun OHC Engine - Nissan # 9996-M8012) states that as a rule of thumb use 0.005" per inch of bore on #1 compression ring & 0.004" per inch on #2 compression. Oil is not critical - 0.010"-0.040" is ok. This gives most engines (avg 3.4" bore) 0.017" on #1 & 0.014" on #2. Bearing in mind that 0.001" bore taper will change the ring gap by 0.003" through its travel.

Incidentally, this is an easy way to roughly measure the bore taper - measure the gap @ TDC & BDC & div by 3.

You should also get a copy of the Tom Monroe 'How to Rebuild Your Nissan/Datsun OHC Engine' (HP Books) (Nissan #99996-M8013)

Thanks a lot for the reply Ben, looks like I may have to bore the block and replace the rings.....Will also look into investing some $$$ on the books you refer to. Thanks once again.

Marc.