Can't get my jug on

[viclioce]

Can't get my rings to close down enough to slip the cylinder jug on. I believe it's my top ring. I'm able to get it over just the bottom ring when the top ring is not in place. Model 99 Road Toad! Help please! ; D Victor

[socalhodaka]

did you set your ring gap?

[socalhodaka]

Setting the ring gap today.

[ossa95d]

I know you know this but once you know the ring end gap is correct, also make sure the gap is situated at the locating pin in the piston ring groove.

[Bill2001]

Brand of piston/rings? Press one end of the ring into the groove and ensure that the ring is not "bottoming out" in the groove. Sometimes there will be a boo-boo with a thick ring and a shallow groove. And of course, pay attention to the ring pins.

[viclioce]

I'll do the ring gap and report back. However the piston is already on the rod. -Victor

[socalhodaka]

Ring gap specs are in the repair book

[hodakamax]

Just agreeing with the Gang. Check that end gap and make sure the locating pin is at the opening of the ring. I make a mark on the piston with a marking pin where the locating pin is to make it easier to see if the ring is properly aligned on the pin. Ring end gap is usually about .004" per inch of bore. A 100cc with a 2'' bore needs about 2x .004''= .008''.

Max

[viclioce]

So why is it with the other Wiseco piston & rings I only had to install the rings on the piston & drop the cylinder on?

This is an original Art .020 piston & the .020 NPR rings for it. So it's possible I may have to file the ring ends down? I've never had to do this before. So it's a durprise to me. ; D Victor

[socalhodaka]

Max, what I love about this forum is a thing like marking the top of the piston were the pins are.The cool little tricks from one to another, so simple.

[thrownchain]

Most people who bought Wiseco and other aftermarket pistons didn't check end gap, as long as the cylinder went over it that's the way it went. One thing you may have is bigger rings that the. 020 that go with the piston. Only way to tell is to check end gap. They can be filed down to work if that's the case.

[taber hodaka]

Why did it work with other pistons?? You were lucky, rings should be within tolerance. Rings must be fit in the cylinder with proper gap and there is acceptable limits. I would never expect it to work if I did it that way ( trial and error). So make sure the rings have the proper end gap from the bottom to the top. Make sure the rings fit the piston and that you can bring the ring gap together on the piston by hand. I would take the piston off the rod, it would probably be easier. I would read the manual covering this and I would have to do it a few times. I do admire all you have accomplished, in a short amount of time and that you are helping the younger generation. What ever is solved here helps others. -----------Clarence

[hodakamax]

Just because it worked before doesn't mean things can't go wrong. You may have been lucky it didn't go together saving you from certain seizure and damage of piston and cylinder. This is one part of engine building that can't be overlooked. Usually they don't need filing for clearance but there are variables in manufacturing or worse yet packaging which I just encountered in my last build. Put this procedure on your list of things to do every time. Most important!

Max

[Bill2001]

Exactly. I call that "checking the fit and finish" of every part as it's installed. 99% of the time things will simply bolt on. But parts are manufactured and packaged by humans and somrtimes things happen. It helps to be an obsessive old guy.

[Kels]

Most rings have a top side and a bottom side.. If you install the ring upside down, it will not sit in te ring groove properly... Just a thought

[viclioce]

So how do I tell which side goes up? This has a thin inner ring and a larger outer ring. I gues you would describe it as "L" shaped? I have it on the piston with the L opening facing down! I assume that is correct? ; D Victor

[taber hodaka]

When the bottom drops out make sure you're on top. Type in Dykes piston ring on the internet, there should be a good enough picture to see. With you talking about a L ring that would be a dykes ring. With the piston vertical with the dome up, if you put a L up along the piston on the left side, it would face the proper way. The dykes ring is like a bowl facing up as the piston, motor, engine fires the pressure forces the ring outward making a better seal. Motors are electric engines run on fuel. With the L opening facing down --- I don't follow what you are saying.----------Clarence

[Bullfrog]

If you put the ring on so the ring cross section looks like this: !_ (piston) _! then you have it right. Horizontal part of the ring is fitted in the ring groove and the vertical "legs" point up. If the vertical "legs" of the ring are pointing down when installed on the piston, the ring is on upside-down.
Ed

[MTrat]

Dykes rings should only fit properly in a piston with groove designed for them. They're not used in pistons made for square section rings, are they?

[hodakamax]

I'm getting lost, is there a two ring RT piston where the top one is a dykes? L rings won't go on upside down, at least the ones I've seen. Any pictures Victor?

Max

[viclioce]

Pictures to follow. Chasing down rings for this piston has been quite a job. Rich sold me the piston he had on hand. But he had no rings. Then I mistakenly bought a set of .020 Wiseco rings for it, & thankfully, Rich called me and reminded me it was an Art piston & the Wiseco rings wouldn't work with it. Then Bruce stepped in and said he thought he had a source for the rings for the Art piston and came through. So 4 sets of rings later, I finally have what should be a complete top end and just need to do the ring gap to make it work. I was just surprised that the lower ring fit without gapping while the top ring will need this done. And thanks Ed! I was installing the ring opposite to the "sketch" you provided and will turn it over! ; D Victor

[taber hodaka]

Good you have it figured out now we can see progress. Max I think you could put the dykes ring on upside down, but it would probably have 80 thousands clearance and it sure is not going to fit in the cylinder. We can always learn things I liked seeing the file held in the vice, sure looks better than trying to hold the ring and file at the same time. ------Clarence

[ossa95d]

I have not seen a two ring piston where the top ring is a Dykes. Usually Dykes ring is used in a single ring piston. The top of the piston is machined to allow clearance for the vertical leg of the ring. A Dykes ring will not work in a piston that is not machined to allow it to fit. Photos would help.

[Bullfrog]

The part number for the top ring of the Road Toad is a "93" series number. So it comes from the chrome tank Super Rat single (Dykes) ring ART piston. The same ring is used in the Model 98 (painted tank) Super Rat - also single (Dykes) ring. So, the top ring on the Road Toad is indeed a Dykes ring . . . for the OEM ART piston.
Ed

[viclioce]

That's good info to have, Ed. Thank you very much. ; D Victor