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Piston Ring Set Question

Posted: Mon Jan 02, 2012 9:15 pm
by 53a1
Hello.

I have a new box of piston rings and noticed the two compression rings that would go on one piston look identical. Is this normal or should there be a different edge for each top & bottom? Basically all the compression rings in the set are the same.

The instructions don't say anything special about the compression rings other than the mark on the ring should point to the top of the piston.

Is this correct?
Thanks.

Posted: Tue Jan 03, 2012 2:35 pm
by 53a1
Can someone please help out? Hasn't anyone ordered new rings in the past?

Thanks.

Posted: Tue Jan 03, 2012 6:03 pm
by danrothe2001
What brand? Normally there is a difference, but not always easily noticed. Does the package show a top and second ring and they just look the same? Most top rings are square or have a bevel that goes up. Most second rings have an inside bevel that goes down with a marking for up along with a taper face, bigger at the bottom. Think squegee to scrape the oil back to the pan. Sometimes they will have a square groove on the outside that goes down to help scrape the oil. Probably not your case since you say they look the same.

Dan

Posted: Tue Jan 03, 2012 7:01 pm
by 53a1
Thanks for the help.

The two compression rings look the same. They both have an inside bevel and the instructions say this should point up. My concern was the outside edge. They both look flat and I thought the outside edge should have a taper or bevel or something like that. Just wanted to make sure the rings are correct.

The packaging has three internal compartments for what I assume is the 1st & 2nd compression rings and the oil rings. I will put them in according to how they were seperated in the package but again, the instuctions only say to point the internal bevel on the compression rings towards the top of the piston. The instructions say nothing about one compression ring goes in before the other.

Posted: Tue Jan 03, 2012 9:30 pm
by wesk
I have a similar set of rings I am installing in a .030 OS M38 engine. They are Mahle and yes both the compression rings are the same. I believe this is a cost cutting measure by the ring manufacturer and they have decided that the extra inner bevel on the second ring is not important.

Posted: Tue Jan 03, 2012 10:29 pm
by 53a1
Thanks. Just wanted to make sure.

My set has the inner bevel on both compression rings. Unfortunately I already installed the rings on the piston and threw the box away so I can't tell you the maker. I'll ask the machine shop when I go back this week.

I'm guessing the inner bevel pushes the ring out on the compression stroke.

Posted: Wed Jan 04, 2012 1:11 pm
by wesk
I wouldn't say "pushes" but rather allows the outboard edge of the ring to slope downward more during the upward travel of the piston.

Posted: Wed Jan 04, 2012 11:52 pm
by danrothe2001
Just opened my Hastings rings and the top is plain with no marks and the second has an inner bevel that goes down with a top mark.

Dan

Posted: Mon Jan 09, 2012 10:46 pm
by 53a1
So it sounds like my instructions are wrong. They tell me to point the bevel on the lower compression ring up.

Posted: Mon Jan 09, 2012 11:36 pm
by wesk
In your first post you said:
The instructions don't say anything special about the compression rings other than the mark on the ring should point to the top of the piston.
then above you said:
So it sounds like my instructions are wrong. They tell me to point the bevel on the lower compression ring up.
Very confusing statements. Let's try to sort this out. It would help if you post a copy of your instructions and a photo of the rings.

Generally when using after market rings or pistons there will be differences from what you see in the factory publications. The key is you must simply follow the ring manufacturer's instructions whenever there is any conflict with the Willys/Kaiser factory manuals.

Posted: Tue Jan 10, 2012 4:32 am
by artificer
Generally rings will have the top marked as such or a T have a . or -.
Rings do & are designed to twist in operation also bevels & cutouts can be designed to increase both scraping & sealing on different strokes.
There are many differences between manufacturers & you should follow their instructions.
You need to check all ring gaps about .003" per inch of dia [.009"] @ the bottom of the bore [unworn portion] unless the engine has been bored & honed then you can check @ the top.
The piston must be totally clean of all carbon in all the ring grooves. Check each ring for back clearance in it's piston groove [that is the ring must sit back into the ring groove] This done by turning the ring & rolling it right around the ring groove ensuring there are no tight spots. While doing this you should check the side clearance which is about .002" if more sometimes the ring groove can be machined & a spacer fitted.
Segmented oil rings are not checked the same but fitting them the correct way is critical.

If just re-ringing always remove the ring ridge [otherwise you will end up with new rings broken in short time] & hone then thoroughly clean the bore & crankcase.

Posted: Tue Jan 10, 2012 12:03 pm
by 53a1
Thanks guys for your help. Based on all the confusion I re-checked my rings and I confirmed that all have a dot (looks like a center punch mark) on all compression rings about an inch from the gap. All my compression rings have an inside bevel on the same side as the dot. Instructions say dot goes up on all rings so all inside bevels are up.

I've read that there are many rings where the lower compression ring bevel goes down so there is some confusion with this topic.