Rings (Piston)

[SurfBeat]

I have two questions:

1. After attaching the pistons to the rods and next endeavoring to slide the pistons through the cylinder I noticed that the rings on one piston were separated father apart than the rings on the other piston.

Albeit they look new, nonetheless I pondered whether the separation is a problem?

I am presuming that there would be a separation considering the fact that the ring has to be spread apart to attach to the piston, thus, where enclosed in the cylinder the rings compress? Is my thinking faulty?

2. Albeit I took every precaution when I slid the pistons through the cylinders to ensure that the locating pin was centered between both side of the rings, nonetheless I wondered, if I did not, would the create a problem?

 

[SurfBeat]

Another piston question.

I'veread that when installing the rings on a piston, the edge on both sides of the rings must be centered on a tab located on the piston.

Can I presume that if they were not centered, thus one side of the ring covered the tab, then the piston would not slide over the cylinder?

I am hoping that is the case because as I have done since the beginning of my rebuild project, I wonder if I did everything correctly!

In my case, the pistons slide up and down in their respective cylinder with ease, so, tomorrow morning it is time to drop the engine in the hull and endeavor to align the engine and the jet pump shaft without special tools.

Does anyone have a suggestion how to do that?

 

[SurfBeat]

Let me try again to get someone to provide an answer to my Piston question.

It is time to drop my engine in the hull, however, I've had one issue on my mind since I dropped my Pistons inside their respective Cylinders and am about to seal eveything up.

My Clymer's instructed to ensure that each Ring is CENTERED adjacent to the Piston Locating Pin (PLP), or in other words, the edge of each side of the Ring centers, but does not touch the PLP.

In my specific case, albeit I centered each Ring as instructed before dropping the Pistons into their respective Cylinders, nonetheless I've wondered whether the Rings moved at that time I did so, thus rather than centering the PLP, they overlapped it?

I opined that in light of the fact that the Pistons move smoothly in their respective Cylinders, then I performed the task correctly, or if I didn't, then at some point when I start the engine the Rings will get to where they are supposed to be.

Any comments would be appreciated as I want to drop the engine into the hull later this morning.

One other question regarding Rings.

I surmise that when installing the rings, the gap will be enlarged just by installing them, (expanding to install) so, if one Ring is looser than the other, no big deal because the Cylinder keeps the Rings compressed?

 

[Dr Honda]

OK... I'm going to give you a little advice. Please don't take this the wrong way, since I'm not trying to be a jack-off. But stop using "Big" words. Three reasons. one... most people on this board don't understand them. Two... it makes things more complex, and three... you aren't using them properly. (your posts are hard to read) I have 8 years of college, and you don't see me doing that. I find that keeping it on a 9th grade vocabulary level works the best.



OK... now for your question.

Since there are multiple questions, but they are all kind of asking the same thing... I'll give you a blanket answer/explanation.


Piston rings. They are made from cast iron, and ground into size and shape. Even though iron is maliable... cast iron isn't. So, what does that mean? it means that it can't bend. (it will just crack) So, opening the rings to drop them into the ring-lands, they won't "Open" up. Most rings these days have Molybdenum (moly) in them. This helps them live longer as moly is a good mineral for lubrication.

Before assembling the engine, the rings need to be put into the cylinder, and the end gap measured. If it is too tight, then the end of the ring must be filed to the proper gap. Since the rings are iron, the will expand more than you would expect, and enough gap is critical. The gap is listed in the manual.


The rings don't have to be perfectly centered over the pin. The pin just keeps the ring from rotating an edge over into a port. If that happened, it would break. When the book was saying it needs to be centered over the pin, that's just so you didn't crack the ring pushing it into the jug.

Hope you didn't get mad at the first part... and I hope that covers the questions.

 

[SurfBeat]

In consideration that I became a member to learn how to keep my Seo Doo running without having to rely on a mechanic at some dealership who may not know much more than this Shade Tree mechanic, Dr. Honda, I don't take umbrage over your opinions regarding my writing style.

In fact, I appreciate the time you have taken in the past to provide me with helpful, propitious, relevant information to questions that I proffered on this site.

That said, I think your opening comments, because they not only may have insulted some members and the fact that some other parts of your opinion are dispositive and unsupported by the facts, in my opinion you should have sent them to me via a personal e-mail. I wondered, what were you trying to prove!

Whatever your reasoning, this is a Sea Doo forum, not a debate forum on writing style and education level, therefore, because like everyone else on this site I really want to only focus on Sea Doo issues, this issue is closed for me.

On a side note, because I graduated from college (in six years) earning both B.S. and J.D. degrees, it is impossible for me to follow your suggestion to write at a 9th grade level.

As noted in my Threads, I endeavor to make my questions clear, albeit I will acknowledge that they may be inane for real mechanics.

Let me again explain the questions I really would like answered and hopefully someone will not only know the answers, but will take the time to provide them.

I am sure someday, someone may have the same question and vola, this site will have it. Enough about non Sea Doo matters.

1. My Clymer's Sea Doo Shop Manual states that "when installing the Piston Rings, spread the ends of the Rings over the Pistons and place them into their proper grooves."

My question to that instructional material is: whether or not it matters when spreading the Rings for installation, one Ring is spread wider than the other, thus, resulting in one Ring being looser than the other?

In my case, unlike my bottom end, my top end was in perfect condition, thus I did not have to remove the Rings after I installed the crankshaft, however, when sliding the Pistons into their respective Cylinders, it seemed like one Ring was a tad looser than the other.

2. My second question pertains to the Locating Pin that is found inside the Ring grooves.

My Clymer's SD Shop Manual instructs to "align the ends of the Ring with the Locating Pin."

In my case, although I did just that when installing the Rings, however, when I was depressing the Rings to slide into the Cylinders I wondered, could the Ring have moved out of alignment to the point of overlapping the Locating Pin?

As a matter of background information, after I slid the Pistons into the Cylinders, each Piston moved smoothly.

Bsed upon that fact, can I concude that the Rings are properly aligned with the Locating Pins?

If not, how can I know that they are?

 

[seadooya]

if the ring/s overlaped prior to install, the cylinder would not accept the piston.

You'll be alright, chief. Tighten-ur all up, and hit the starter button.....:reddevil:

 

[SurfBeat]

Thats what I thought, however, because you're the Man and I'm only a Shade Tree mechanic, that is why I seek out sound advice (2nd opinion) from the Men with real SD wisdom on this site.

Thanks for very much your very prompt and on point reply. Hopefully, tomorrow I will be hitting the starter button, unless I have to seek out the "special" tool to align my engine and the drive shaft.

 

[Dr Honda]

Sorry if I offended you, but it was only constructive criticism, since I've noticed your threads are going unanswered. You will probably get more answers if you dumb it down a little.

As far as explaining my background... I was simply trying to say that I am educated, but I would prefer to read a post that is clear and simple to read.



Seadooya gave you the answer you were looking for, but just to add to it.....



1) The explanation of material type is to let you know that they aren't able to be bent. Before you can expand a piston ring past it's "spring" point... it will break. So, opening it over the piston will not cause it to be looser. If it is, you should verify that both rings were the same size.



2) If the piston rings were not properly centered, you would have never gotten the jugs installed without breaking the rings.


Now... as Seadooya said... hit the start button.

 

[SurfBeat]

No problem Dr H. I've always appreciated the guidance you have provided me and in most (99%) cases, it was very useful.

In fact, whenever I see a reply to a many posts made by you to others Threads, I take the time to read it because you seem to be very knowledgeable.

Moreoever, when SeaDooSnype made mention of your name as to members he thought were very knowledgeable on the subject of SD's, that fact I took notice of.

Since we both have explained our positons on the issue of language, lets just "forget about it" and get back to having fun.

I need your help a lot more than you need mine, unless of course, you find the feds knocking on your door with a warrant.

 

[Dr Honda]

All is good :cheers: