EnzoSpeed

So I was gapping my rings yesterday and ended up with .0018 on the top and .0020 on the bottom.

I was actually shooting for 17/19, but with the crappy ring filer and crusty feeler gauges I have, I ended up with 18/20.

So I was wondering, how much does opening up the gap really affect compression/hp? Going by the CP calculations, the recommended gaps were like 20/22. And most people run tigher gaps than that.

But seriously, the difference between a .0015 gap and a .0020 gap looks like the width of a human hair. Can such a small difference actually have a noticeable effect on power?

Fkned

To big of a gap could hurt power depending on the amount of gap but .001-.003 isn't going to affect much.Too small of a gap and your risking having the ends of the rings meet and that's a problem the rings will stick out of the pistons ring land and will bind or break in the cylinder usually.Ring gaps are there to accomodate the rings growth when the motor warms up.

D@nnY

it wont make a difference ..the clearence you have is actually perfect

W C L

i like to run my gaps a lil bigger, i have always looked at it as lettin the motor breath with the bigger gaps and maybe pickin couple extra ponies, helping with crank case pressures(blowby...I do this on high hp turbo cars and havents seen a problem with doing it this way..

EARLdaSQUIRREL

ran mine at 18 and 20 on my built ls with cp pistons, jeff evans had a write up that for a gsr build and i believe these are the specs he recommended

Fkned

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Big Will &raquo;</TD></TR><TR><TD CLASS="quote">i like to run my gaps a lil bigger, i have always looked at it as lettin the motor breath with the bigger gaps and maybe pickin couple extra ponies, helping with crank case pressures(blowby...I do this on high hp turbo cars and havents seen a problem with doing it this way..</TD></TR></TABLE>Opening up the gaps to bigger then is needed increases blow-by and crankcase pressure and robs cylinder pressure,only very little maybe not even noticeable,but it does.You only need to run the size gap that will allow the rings to fully expand but not have the ends touch,anything more causes blow-by to some degree.

mamaboy

forged piston expansion explains for bigger end gaps on aftermarket pistons. stagger your rings to lessen blowby and to provide better compression

EnzoSpeed

Well I guess I need a new ring compressor. I tired using the kind that you tighten with an allen wrench that squeeze all the way around the rings.

But after installing my pistons yesterday, I popped them back out on a hunch. Just as I had suspected - when I tightened the compressor, it moved all my rings around a screwed up the stagger.

SOHCD16y8

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EnzoSpeed &raquo;</TD></TR><TR><TD CLASS="quote">Well I guess I need a new ring compressor. I tired using the kind that you tighten with an allen wrench that squeeze all the way around the rings.

But after installing my pistons yesterday, I popped them back out on a hunch. Just as I had suspected - when I tightened the compressor, it moved all my rings around a screwed up the stagger.</TD></TR></TABLE> If you use it right they wont turn, it took me a couple tries to get it right, the key is to hold one side against the rings and pistons and then tighten to prevent them spinning with the compressor.

EnzoSpeed

I just horsed around even more that that gay ring compressor. What a piece of crap.

See, everyone told me to buy the scissor type compressor, but I had to pinch pennies and go the the $3.99 ebay special

99_GS-T

Rings will move around while the motor is running anyway. I wouldn't be too concerned with ring stagger.

NJIN BUILDR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 99_GS-T &raquo;</TD></TR><TR><TD CLASS="quote">Rings will move around while the motor is running anyway. I wouldn't be too concerned with ring stagger.</TD></TR></TABLE>

You are correct.Remember we are dealing with pressure not light.Pressure dosn't care to much about line of sight.This is on my top three automotive myths."My ring gaps lined up and I lost all the compression".
Glenn

EnzoSpeed

No ****? Well why does helms/haynes/honda/cp/je/arias recommend staggering them?


And that brings up another question - why does my Haynes have a completely differnt stagger pattern than what CP recommends?

Fkned

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EnzoSpeed &raquo;</TD></TR><TR><TD CLASS="quote">No ****? Well why does helms/haynes/honda/cp/je/arias recommend staggering them?</TD></TR></TABLE>Since I also don't believe that lined up ring gaps affect power I'll offer an opinion on maybe why it's done,at least why I do it.I feel it has more to do w/cylinder/rings break-in then with loss of power.I am assuming that the top and bottom rings don't rotate during intial break-in(since I really don't know )so if the rings aren't staggered then the gaps may create a thin section that doesn't get worn preventing the rings from rotating as usual.If the ring gaps are staggered then each ring takes care of the others gap and the cylinder/rings are broken in correctly.I don't know I'm pretty tired

EnzoSpeed

Well, that makes sense in part... But it doesn't explain why there are usually specific stagger patterns rather than directions that just say "stagger the rings".

NJIN BUILDR

I've seen several recommended staggers from reliable sources.I stagger them equally apart,but don't get carried away with the this detail.I've been told by some Nextel cup (NASCAR) engine builders that the angle off the crosshatch determines the speed at which the rings rotate,similar to threads on a bolt.I have now way to be sure that is correct,but I tend to believe it may be true.
Glenn

EE_Chris

I had always wondered about ring stagger and rotation while the engine is running.

You'll always see engine builders (and books) telling you to keep the gaps off the major thrust axis. Well if they rotate, won't they eventually get there? If the rings rotate, do they do so in unison? Will all rings rotate the same amount all the time thus keeping the staggers where they were relative to one another?

Confused on the physics, so I'll just stick with Helms recommendations here.

EnzoSpeed

Maybe the idea is to keep the gaps off of the thrust surfaces during break-in? I can see how the square ends of the rings might dig into the cylinder walls if they're on the thrust surfaces.

Jan and Dean

well if you guys want to argue mute points i guess this is the thread lol

just put the ******* in there and enjoy your motor.

simike

I am going to drag this thread out even longer because I have though about this also.

After talking to several people I believe the reason you stagger the rings is to get a better seal (less blowby). The rings will float while the engine runs, but the chances of them all lining up at once while the engine is running is very low!! If they were to line up your compression would fall way off because you have a direct path (like a hole) into the crankcase (or at least that is what I think). They will eventually float away from each other again, but why start them out lined up? Reduce their chances of alignment as much as possible from the start.

Now why are there set specs for ring alignment? I don't know. Why not just make sure they are all equally spaced? I followed the Helms positions also the same way Jeff Evans recommends.

Dr Pooface

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by simike &raquo;</TD></TR><TR><TD CLASS="quote">If they were to line up your compression would fall way off because you have a direct path (like a hole) into the crankcase (or at least that is what I think). </TD></TR></TABLE>

As said before, pressure does not care about line of site. A hole is a hole, does not matter if they line up or not.

EnzoSpeed

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dr Pooface &raquo;</TD></TR><TR><TD CLASS="quote">

As said before, pressure does not care about line of site. A hole is a hole, does not matter if they line up or not.</TD></TR></TABLE>


Yeah we read what you said before, but it's not true. The pressure is going to go blowing through the first compression ring and hit square into the second ring. If there is no stagger, the pressure will go straight through both rings.

You think the combustion gases go past the first ring, then instinctively make a 90* turn and go looking for the gap in the second ring? No, they have to SLAM into the second ring before dispursing and exiting through the gap.

Dr Pooface

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EnzoSpeed &raquo;</TD></TR><TR><TD CLASS="quote">
You think the combustion gases go past the first ring, then instinctively make a 90* turn and go looking for the gap in the second ring? No, they have to SLAM into the second ring before dispursing and exiting through the gap.</TD></TR></TABLE>

I think directional changes would have a negligable effect, in this instance. There's nothing instinctive about the way gasses move. In some instances baffles actually help air movement, ie anti reversion chambers.

simike

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dr Pooface &raquo;</TD></TR><TR><TD CLASS="quote">

I think directional changes would have a negligable effect, in this instance. There's nothing instinctive about the way gasses move. In some instances baffles actually help air movement, ie anti reversion chambers.</TD></TR></TABLE>

Yes, but think of it as an OEM muffler vs a straight through design.

EnzoSpeed

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dr Pooface &raquo;</TD></TR><TR><TD CLASS="quote">

I think directional changes would have a negligable effect, in this instance. There's nothing instinctive about the way gasses move. In some instances baffles actually help air movement, ie anti reversion chambers.</TD></TR></TABLE>


I'm just thinking in terms of an explosion. Coming from someone who used to make some serious fireworks and explosives, I can tell you that the combustion gases are moving too fast to change direction.

If I put some flash powder in a tube with a hole in the end and light the powder, it's going to ignite but not explode. But if I put a staggered series of plugs with the same sized hole in the end of the tube, lighting the powder will result in an explosion. The gases are just moving too fast to make any kind of 90* turn.