Problem installing new rings in 240

[SW EM]

I'm putting a 240 back together and I'm running into a small problem installing the Pistons with the new rings into the cylinder. I am using a ring compressor, but the Pistons are going in hard. A rubber mallet is needed to install them. I checked the end gap on the 2 compression rings before installing them on the pistons, and they had .040 out of the box (hastings).

Where I think the problem is, the new oil rings were tight in the cylinders. Is this common? Should I file them down? The hastings ring set came with 2 spacers and an oil ring. I used the original "spring" (flat black ring that goes under the oil ring and spacers). Do I need to use this "spring"? I assumed so that's why I put it on, but when it's all on the piston and I force it into the cylinder, it is VERY tight. What advice do you have? Thanks

 

[rustred]

first of all you have a problem right off the bat. . .040 is way too much end gap. the gap should be .004 for every inch of bore, so total about .012.
depends what you mean by hard going in. i tap them in with a hammer handle. then they push in with the handle once rings are in bore. yes u need that expander ring on oil ring. need to make sure the spacers are correct too. make sure bore is well clean and oiled along with the piston.
you may have the wrong rings or incorrect measurement.

 

[Jim Becker]

Not seeing what you are working with, I can't be certain of what is correct. However, these statements are generally true about piston rings:

1) Different manufacturers have different designs/styles that they prefer, especially with oil control rings. Mix and match of parts from different suppliers is usually a source of trouble.

2) With rare exceptions, a new "set" of piston rings generally includes everything that needs to go back in the ring grooves as they are all parts that are subject to wear and/or breakage.

Based on the above, my guess is that you need to NOT use the "springs" from the old set. Just put in the new parts.

 

[Jim Becker]

Well, I see we came up with some different advice. Did the ring set come with instructions? They usually do. If not, you might do some reading here:
https://www.hastingspistonrings.com/tech-tips-faqs

 

[rustred]

ok, i just saw u used the old expander ring. NO, throw that out, as thats your problem. recheck ring end gap cause if its as you say .040 those rings are wrong set.unless you have badly worn sleeves

 

[rustred]

yes read jims tip there , lots of info there as i have not covered that much. but it is important to check the gap at btm. of cyl. as no wear takes place there. then when you check at the top you can see the amount of sleeve wear.
hey how come we answer questions when all info is online. lol.

 

[teddy52food]

Did you get all the old carbon out of all the grooves?

 

[old]

If you did not clean out the piston ring grooves super good that is what will happen and also it will cause broken rings and can also cause scored cylinders. Learned that the hard way back some 40 plus yes ago

 

[SW EM]

With every engine overhaul kit I've baught from this website, the end gap on the new piston rings (with new sleeves) has been way over the minumun .004/per in. bore spec. I've never had to file any rings from them. Yes, the grooves have been cleaned. If I remove the expander ring, then won't that remove the expanding pressure on the oil ring? A new one didn't come with the kit. And yes I read the instructions. It said to install the expanding ring under the oil ring and spacers. They were just unclear on whether or not to use one if it was provided, or use the original one.

 

[rustred]

dont use anything that was in old piston ring set. that is garbage can stuff.
the new rings come with what is required. some oil rings have expanders some dont.
depends on manufacturer.

 

[rustred]

also if the ring end gap is over spec i would be looking for better manufacturer. dont forget filing is too increase the gap so unsure what u mean u never had to file rings, and you say they are all over spec.? i have never filed rings end gaps either as its not very common to do that. put an old ring in the bore on top of the new ring and you can see how much rings do wear by the increase in old ring gap. the oil rings are not for compression ... just a wiper for the oil.
any rings i used are very close tolerance to the spec.
possible these online parts are chinese stuff and can see that happening.
hastings or ihc stuff or other brand names are good.
dont forget to install rings the right side to top.
and if installing a ring thats over spec on the gap is just like using a used ring then. junk.

 

[rhtx55]

All ring grooves cleaned with tool ?
All ring groves cleaned with used broken ring edge ?
Used or new liners?
Used or new pistons ?

ALL piston grooves must be free from any carbon & dirt residue, bright & shiny.

Use bore gauge to measure top center & bottom of liners inside go side to side, then front to back, then corner to corner.
Write each measurement of each sleeve at each position down.

The difference from top or bottom to middle is the amount of wear.
The difference from side to side, compared to front to back is egg shape wear.

To check new ring fit.
Insert compression ring into respective sleeve & measure end gap top, center & bottom of piston travel. Write each down.
Inset oil ring(s) into respective cylinder measure end gap top center & bottom of piston travel. Write each down.

Call your place of purchase, and offer the information above.

 

[rhtx55]

Once you have everything measured & within specs.
Use a ridge reamer to clean all carbon & reside from each liner at the top above the piston ring travel.
Hone each cylinder using a steady up & down motion to establish a "cross hatch" pattern, do not hone so much that your existing liners with be over spec, if in doubt, replace them.
Once the honing is finished, clean each liner thoroughly, and douse liberally with engine oil. Install rings as instructions provide onto each piston & lube each groove & piston skirt liberally with engine oil. Install pieces of fuel line hose over each rod stud, just a bit longer than the threads. Install your ring compressor, and gently insert the piston into it's respective liner. Once the skirt has been inserted & the ring compressor is at the top of the liner, gently tap each one with the wooden part of a ball peen hammer until the rings are in the liner. You should be able to push the piston all the way down by using the head of the hammer as a handle.

 

[SW EM]

I have done every thing you just said.
Except for when I'm pushing the piston in,
the bottom spacer on the oil ring will catch
on the top of the sleeve, which makes me
believe that I need to either file down the
oil ring and spacers, or remove the original
expansion ring from underneath them.

 

[SW EM]

They are hastings rings. What I meant about filing, is that I've never had to do it with hastings rings. On all my other tractors they have a large end gap out of the box. I install them and the tractor runs great. The old rings were worn badly and had a gap of over .070

 

[Nebraska Kirk]

The hastings ring set came with 2 spacers and an oil ring. I used the original "spring" (flat black ring that goes under the oil ring and spacers). Do I need to use this "spring"?

NO! DO NOT USE THAT SPRING! Do not mix and match pieces of the old oil ring with the new!! Get rid of ALL of the old and use just the NEW! That is what is giving you grief, you are putting in a piece that does not belong!

 

[Buzzman72]

Did you, perchance, measure the ring end gaps OUT of the cylinder bore? because you should be sliding the ring into the cylinder, before putting it onto the piston, and then measuring the gap when it's in the cylinder.

'Cause .040 is a pretty big gap...enough to cause problems with blow-by.

 

[504]

You check end gap by putting a ring inside of a cylinder,(not on the piston) then put a piston upside down on top of it to square the ring in the bore. Take out the piston and measure the end gap. If the rings are not going into the bore as stated either the rings are not going in the ring groove enough or the compressor is just not tight enough letting the rings pop out.

 

[NoNewParts]

agree with the others.
a new ring set is exactly that...new
no old ring parts are used at all...after caliper checking thickness
to make sure you got the right set...in the garbage they go.
Follow directions to install the new oil ring assembly.....different styles exist.
make sure compression rings are in the right grooves and right side up.
stagger the ring gaps.
screw your compressor down [i:d30e24b62a]tight[/i:d30e24b62a], tap em in.
I'm actually a little surprised you could get an 'extra' ring in the groove at all...worn grooves?...wrong thickness new oil ring?

 

[SW EM]

Yes I know how to properly measure the end gap of rings. My question was about the oil ring and using the old expander underneath. I believe I have my answer now. Thanks everyone