7 replies to this topic

[FLD]

I've lazily started looking at piston ring gaps for the Z22 / saab engines.  I would normally just gap them to spec and think nothing of it but with all the crank case pressure discussions recently I started to think more of it.  I was reading that if the gap is too small it can cause issues that ultimately result in the gap becoming too large (Cant quite remember the ins and outs of that).  Interestingly the wiseco spec is quite a tight gap at <20 thou but total seal spec theirs at min 25 thou.  Thought I'd ask here what peoples thoughts are on this before I get filing.

[CHILL Gone DUTCH]

My car/engine new B207 2.2 breathed heavily from day one without a fully open PCV But since PCV is fully open ( vacuum ) despite laminovas & inlet TB and SC being oily slightly the oil usage has gone almost completely I'm now taking steps to reduce/stop oil from getting into the inlet

Edited by CHILL Gone DUTCH, 21 January 2015 - 09:32 AM.

[siztenboots]

with pcv working , oil scraper rings now able to work properly

[FLD]

I'm now taking steps to reduce/stop oil from getting into the inlet

 

Thats why I bought total seal rings.  Gapless top FTW!

[CHILL Gone DUTCH]

To late for me now Lesson learned

[techieboy]

I think Alanoo recommended larger ring gaps (30-40 thou) than Wiseco's recommended sizes. If Total Seal rings are such a good thing, why don't OEM's fit them as standard? Can't be any more expensive to manufacture something similar at OEM quantities than it is to manufacture "standard" style rings. There must surely be some potential downside for them to not do it.

[Exmantaa]

I've lazily started looking at piston ring gaps for the Z22 / saab engines.  I would normally just gap them to spec and think nothing of it but with all the crank case pressure discussions recently I started to think more of it.  I was reading that if the gap is too small it can cause issues that ultimately result in the gap becoming too large (Cant quite remember the ins and outs of that).  Interestingly the wiseco spec is quite a tight gap at <20 thou but total seal spec theirs at min 25 thou.  Thought I'd ask here what peoples thoughts are on this before I get filing.

 

To my knowledge with too narrow a ring gap the ends will butt from thermal expansion and then your  rings start excessively wear the cylinder walls...

Turbo or SC give more thermal load than NA and need more thermal expansion room.

[FLD]

I think Alanoo recommended larger ring gaps (30-40 thou) than Wiseco's recommended sizes. If Total Seal rings are such a good thing, why don't OEM's fit them as standard? Can't be any more expensive to manufacture something similar at OEM quantities than it is to manufacture "standard" style rings. There must surely be some potential downside for them to not do it.

 

Total seal type rings are usually a better grade material than OEM so they do cost a bit more.  They do also cause their own issues in that, because they seal so well, you get a weird in/out pumping of crankcase pressure at idle.