New Rings? End Gap Too Large?
Turbo Mini Forums

http://www.diagnosticengineers.org/journal...edge%20Gaps.php

interesting

Interesting.

I never worry about ring gaps and never have, but then what do I know ?.

I remember reading about that somewhere years ago. I can't say ring gaps have ever been top of my list of concerns ever since. Just goes to show how much complete bollocks is talked about engine building.

huh, that was certainly interesting. Reciprocating refrigerant compressor manufacturers also say that the gaps in piston rings be staggered. And I acctually beleived in it! Thats that out the window then.

Nice find

I think the coin drops when you consider pegged rings


I also read somewhere else that suggests one possible reason why the rings rotate, which is due to the hone in the bore.

Also makes you wonder about Total seal gapless rings

I've read a few articles saying that total seal rings are snake oil.

Also I'm sure John Sleath mentioned to Andy when we had the van rollered that he has known motors that have burnt oil and blue smoked from new with total seal rings. But swap them out with conventional ones and the problem goes away.

If something is worth doing, it's worth doing half of.

he said they smoke after a while sat idling

Could it be to do with the longer period of time on the compression stroke? Or possibly lower cylinder temps? Maybe?

one day boost will be mine!

However, it's a good thing to measure ring gap as we all know what happens if it's too small.
The hone pattern is there to make the rings rotate, why else would you want such a diamond pattern?

I've been told that the pattern In the honing is to hold on to the oil residue??? Any truth in that?

one day boost will be mine!

That is what I was taught too, shinny bores don't hold onto oil

Own the day

No one is disputing the hone is what 'lubricates' the rings in a running engine, but a 90 cross hatch would hold onto oil just as much. I'm with Vegard.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

I discussed ring gaps with three eminent engine builders down the pub after the Autosports show (see current editorial pic in Mini Mag for a clue).
General consensus was that spacing the gaps 180° apart on build made you feel better but was actually useless as rings make roughly one complete rotation per 1000 revs.

Metric is for people who can't do fractions.

First off this guy contradicts himself, saying that the ring gaps dont have to be staggered then he goes to say that when they are staggered they make a "maze" so you dont get blow by....

I always stagger my rings and i always gap my rings, usually very big. So big in fact that my 408 on idle smokes a ton through the catch can filter. This is because its a nitrous motor and you need really big ring gaps for a 400 shot. Now on boost setups we generally run a bit less but not by much. Ring gap is very important for a performance setup and is generally a well kept secret to most engine builders as to what they set them at.

Staggering rings is also important. Yes they do turn and can all line up but what are the chances of them staying there? None i hope because that means they have stopped turning. If your ring gaps and hone is correct they should continue to turn and they wont stay lined up very long.

It sounds like the reason for the top seal rings smoking is they arnt sealing. The reason stock rings didnt smoke is they are a softer material and seated faster/ easier.

-1974 Mini 1000 - BRG Turbo Build Soon to come

-04.5 LLY Duramax - RC/LB - White - Built Trans - EFILive - Dropped 4/6

-2013 TDI Passat - SEL - White - Lowered on Coilovers - Daily Driver

-2003 Silverado SS - 408 Stroker - DP NO2 - Full Suspension ~900hp For Sale

I used to build 600+ bhp leman engines and have installed rings with gaps opposite etc. put the engine on the dyno, strip after and the rings gaps are all over. Regarding gaps. They had to be precise and the edges on the rungs were de-blurred under a microscope.

I've also seen rings which had too small a gap and during running expanded and contacted and caged other problems.

Edited by mossy2a on 26th May, 2012.