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Lots of Questions About Piston Rings


KWRB
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Background: I purchased a Red Power sleeve and piston kit about ten years ago, prior to their being bought out by Reliance. I'm just now rebuilding the engine, my first engine build. I was assembling the pistons and rings over the weekend and mis-fit a ring to a piston (partially in two grooves). When I went to take it out, it broke. So, I'm on the hunt for a replacement. Not surprisingly a single ring is not readily available, but single cylinder sets are. So are four-cylinder sets. However, there are more questions at this point than answers.

My kit has pistons with three grooves and three rings. The set has, for each cylinder, an oil control ring (three piece), a phosphated middle compression ring with a bevel on the upper inner, and an upper compression ring that's chromed.

The kits that I'm finding all seem to have four rings.

Question 1: What is more common generally in an engine, three rings or four?

Question 2: Will my engine have any kind of degraded performance or noticeable issues by having a three-ring piston?

I'm reading more than I ever thought I would about piston rings. I have read about "never, ever spiral a ring onto a piston". Well, I did, then I read this. So, I then removed one unbroken compression ring and there's noticeable wave to it when sitting on a flat surface.

Question 3: If I "spiraled on" all of my rings, should I replace them all, or will it be negligible to performance? Cost is not a consideration here.

Hastings and Total Seal each have kits available for this engine, albeit imperfect matches. Like I mentioned above, they look like they're for four-groove pistons. That in and of itself is not a huge concern. I don't mind chucking a ring as long as the kit contains the one (or ones) I need. However it appears Hastings offers kits with a "reverse torsion taper face" second (and third) compression ring that have bevels on the lower inner, whereas the one I broke was a conventional positive torsion ring with the bevel on the upper inner. I looked into the "reverse torsion taper face" and this appears to be unique to Hastings. I believe the Total Seal product is a conventional torsion ring with the bevel on the upper inner, as there's nothing mentioned in their documentation about "reverse torsion". 

Question 4: What are your thoughts and experiences with this "reverse torsion, tapered face"? Is it a gimmick?

Question 5: What have I forgotten to ask?

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Years ago i was taught about the rule of the 3 “T”s ifn it has tracks, tires or ti…you have trouble… same applies here. 
Seriously though, what do the factory pistons have for grooves and style of rings? 

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15 minutes ago, vtfireman85 said:

Years ago i was taught about the rule of the 3 “T”s ifn it has tracks, tires or ti…you have trouble… same applies here. 
Seriously though, what do the factory pistons have for grooves and style of rings? 

Factory pistons are looong gone, but the book shows options for pistons ((A): Gas/Distillate 3" four-ring gray iron pistons, (B) kerosene 3" four ring gray iron pistons, (C) gas/distillate  3-1/8" Aluminum Pistons and (D) Kerosene 3-1/8" four ring gray Iron. Mine are aluminum and 3" aftermarkets so automatically disqualified from matching anything in the book.

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Basically your rings only need to seal to produce the compression required for combustion, gas lower-diesel higher, now that is a super simplified statement, ring design, composition of materials used, application, using gases to travel behind to push and seal etc are all a serious consideration, I always read the instructions and examine the ring for markings at install and checking/adjusting gaps, I have installed them as you say but bought the tool over 30 yrs ago and use always since, I wouldn’t run without a ring, if the rings aren’t flat now I would replace, easy now at this point, if your asking there’s a little voice telling you what the right thing to do is-listen to it

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2 hours ago, Frank H said:

I would call Hastings and explain the situation.  If the rings are the proper dimension,  I would leave one out. I definitely would replace all of them if you spiraled them on. A ring expander is cheap. 

Would that empty groove tend to be a place for carbon deposits to build? 

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Question 3:  “ Cost is not a consideration “   Then what are you waiting for? Get a full engine set and a ring expander and install them in the order they are packed. Near the gap, they are marked with a dot. Install with dot facing up . No dot means either side up. Any special instructions will be detailed on the package. 
  By “imperfect match” do you mean different style or don’t fit? If you can’t get the rings from the people who made the piston 10 years ago, this is what you’re stuck with. If the rings fit the piston, install them as packaged and don’t worry about the style. Engineering technology has changed in 10 years. If they are too  loose or too tight in the groove you will have to consult your machinist for a solution. Lastly, when mixing parts from different manufacturers, check each ring in the cylinder for proper gap.
   

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46 minutes ago, vtfireman85 said:

Would that empty groove tend to be a place for carbon deposits to build? 

It's the opposite situation. The piston has three grooves, and the kits come with four per piston. So, the piston would be full, but I'd have one left over.

 

11 minutes ago, Binderoid said:

Question 3:  “ Cost is not a consideration “   Then what are you waiting for? Get a full engine set and a ring expander and install them in the order they are packed. Near the gap, they are marked with a dot. Install with dot facing up . No dot means either side up. Any special instructions will be detailed on the package. 
  By “imperfect match” do you mean different style or don’t fit? If you can’t get the rings from the people who made the piston 10 years ago, this is what you’re stuck with. If the rings fit the piston, install them as packaged and don’t worry about the style. Engineering technology has changed in 10 years. If they are too  loose or too tight in the groove you will have to consult your machinist for a solution. Lastly, when mixing parts from different manufacturers, check each ring in the cylinder for proper gap.
   

I'm leaning that way, but I don't know which profile to get.

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12 hours ago, KWRB said:

Factory pistons are looong gone, but the book shows options for pistons ((A): Gas/Distillate 3" four-ring gray iron pistons, (B) kerosene 3" four ring gray iron pistons, (C) gas/distillate  3-1/8" Aluminum Pistons and (D) Kerosene 3-1/8" four ring gray Iron. Mine are aluminum and 3" aftermarkets so automatically disqualified from matching anything in the book.

So it sounds like the aftermarket piston are replacements for (C) gas/distillate  3-1/8" Aluminum Pistons?

Did this piston have 3 rings? Modern gas engines have 3 to reduce drag and improve efficiency  

The question will be what did the motor have for piston before?

If it had cast iron pistons you could run into a balance issue they are likely heavier.

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26 minutes ago, jeeper61 said:

So it sounds like the aftermarket piston are replacements for (C) gas/distillate  3-1/8" Aluminum Pistons?

Did this piston have 3 rings? Modern gas engines have 3 to reduce drag and improve efficiency  

The question will be what did the motor have for piston before?

If it had cast iron pistons you could run into a balance issue they are likely heavier.

I'm fairly confident the engine had cast iron pistons originally. They were 3". I don't think iron pistons are even available, so I'm going to try my luck with these. I hadn't thought of that though, and so I called my engine shop. He gave a very fast and over my head explanation of why that engine's balance won't be affected by the switch to aluminum.

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Update:

Called Hastings and they insisted I email them with tech support questions. Not ideal. It'll probably take a week to have a conversation that could could have been five minutes.

Called Total Seal and they don't offer "those fat rings" anymore, but their tech support guy confirmed that the middle ring is "just a scraper, nothing more" and so profile isn't terribly significant. Very friendly guy and willing to talk and didn't get annoyed or rush me off the phone. I appreciate that.

Called HeavyDutyPros who are my absolute authority on all things engine. I can't recommend these guys enough. As I said before, they're friendly, super knowledgeable and above all, resourceful. They can get all kinds of stuff that is unobtanium. Their sister company is the engine shop where I have my engine work done. They do everything from heavy duty diesels, to racecars. Anyway, they confirmed that a three ring setup is more common as designs are evolved but the kits contain those extra middle or extra oil rings, so they remain compatible with more pistons. We talked about bevels and profiles and more or less, they're not real concerned with the "reverse torsion" shape of the Hastings rings, relative to the traditional positive torsion design. Either way, it's an oil scraper to deal with oil missed by the oil ring. They're going to pursue Hastings and some others and get me a set. I'm going to replace all the rings while the engine is apart, and move on with my life.

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13 minutes ago, KWRB said:

I'm fairly confident the engine had cast iron pistons originally. They were 3". I don't think iron pistons are even available, so I'm going to try my luck with these. I hadn't thought of that though, and so I called my engine shop. He gave a very fast and over my head explanation of why that engine's balance won't be affected by the switch to aluminum.

I'd be curious as to the weight of the cast iron vs the aluminum you have.

I see the gas/distillate are and 1/8 inch bigger was this done to keep the same piston weight?

Its a low speed engine so balance isn't as critical

I would ask the engine shop what they recommend for rings they deal with it everyday and know what works well 

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what engine are you working on??  rings is one thing that is not hard to get. definitely never leave one out. you probably know,.. but make sure end gap is checked  ,.003 -004 for every inch of bore. make rings are not upside down or you will pump oil out. go by the dots, bevels . when none of these either way is good. chrome to the top ring. make sure piston ring lands is not wore. . like .002 feeler gauge between ring and groove would be max.

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19 hours ago, jeeper61 said:

I'd be curious as to the weight of the cast iron vs the aluminum you have.

I see the gas/distillate are and 1/8 inch bigger was this done to keep the same piston weight?

Its a low speed engine so balance isn't as critical

I would ask the engine shop what they recommend for rings they deal with it everyday and know what works well 

With balanced crank in engine the piston weight won't effect the balance if pistons and rods each weigh the same. Bigger bore and a dome to increase compression was  to increase power. Way back when IH first started selling aluminum 3-7/8 pistons for a farmall M  they claimed a added 4 HP over the cast iron.    

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3 rings are modern as compared to 4 rings, I have a Ford farm stock pulling engine 401cid where I left the 4th ring out.  With metallurgy advancements rings have become thinner as they conform to the bore better under bore distortion.  There are companies that offer ring spacers to utilize a thinner ring in a existing wider ring land piston.  Total Seal is my go to for my ring needs, they seem to be the leader in cutting edge technology.

Scott

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