total seal piston rings?

[12Ounce]

An interesting link on subject:http://www.racetep.com/gapless.html

[pmkls2]

As far as the longevity of a gapless ring vs. an OEM ring I can argue for the C&A design but not the total seal design. The C&A design has a 1 piece overlapping second ring. The overlap is enough that as the ring and cylinder wear the ring can expand and still be overlapping itself so as to still be gapless. Honestly, I prefer not to rebuild an engine that doesn't at least have a new set of pistons. Even if you dont overbore the block your pistons still show wear as well and if you have enough wear they will rock back and forth in the bore and cause inconsistent sealing and piston slap which accelerates ring and cylinder wear. It costs less than $100 to have a 4 cyl block bored and about $150 for a new set of OEM style pistons. If you are going to go that far why not do it right ? Just my 2 cents guys

[Chezedik]

It is a common practice to put a motor together without boring and without replacing pistons. It is outlined in the Nissan FSM. There can be problems however, when you come down to worn walls (which will be figured out in the end gap test, in terms of standard rings, not file fit, if only...), but taper must be checked with a dial bore indicator that reads in tenths (ten thousands of an inch or .0001").

A piston should never touch the walls, while there is sometimes some scuffing, this is an indication of side loading, excessive ring wear, or excessive bearing wear, sometimes it does happen. When this is the case, or when you suffer catastrophic engine failure which causes piston or wall damage, then you replace the pistons and possible bore over.

Did you replace the pistons in your last rebuild without doing these checks?

[pmkls2]

I have overhauled several engines without replacing the pistons or overboring. Generally speaking they all only had about 100k miles or less and were commuter cars and not driven hard. But, from the way you speak it sounds like your engine has lots of wear. The thing to remember about reusing the pistons is that you have to add the amount of cylinder bore wear and the amount of piston wear. If they are both worn enough then it is enough to cause issues later on. Granted you may only be a few thousandths off on the bores and on the pistons but when you add that together then your piston to wall clearance becomes excessive. If you plan on pounding on the engine I just dont see why you dont go the extra mile. Anyhow thats just my opinon I didnt really mean to spark a debate.

[Chezedik]

No, and I don't intend to flame. I don't know how bad my wear is, but I guess I will figure out shortly. Another issue I have is that it won't start, so I cannot get a good compression test. So I guess we will see when this ****ing snow melts.

[nuts510]

I don't recommend total seal rings in boosted motors because basically they replace the second compression ring with a ring that is a two-piece thinner ring because of that I feel that boosted motors would be prone to break them then really nasty things start happening. In naturally aspirated motors I have gotten great results with them but they do seem to take a while to seat in, they seem to want to use a little oil during break in time

[Chezedik]

May be neither here nor there. I just got my car started yesterday, so I will do a compression check. It is running like ****, with low vaccum, but I remember jacking with the throttle, so I will reset that and check for leaks. Blew up an AC hose warming it up, so I guess I am going without AC afterall.

[Bigvinnie]

What ever the case I think gapless rings are an excellent alternative for guys swapping the 90 SOHC pistons into the DOHC engine.As far as I know I've been looking for this alternative for years, so not to overbore.I'm pretty sure that gapless rings were also only meant for synthetic oil, by design it would seem to work more effectively in the reliability department.

[Chezedik]

What about this...

My new compression results are much better:160, 160, 145, 160. Clearly, there is some issue with #3, is there any hope that it will seal? At one point that cyl siezed, so there may be wall wear. Does anyone think that with Total Seal, it will fix that one cyl, and bring them all to the same level? Also, if anyone is wondering, I am 8.6:1 and pretty sure I have a cam timing issue (7" Hg is a good sign, I think).

[Bigvinnie]

What about this...

My new compression results are much better:160, 160, 145, 160. Clearly, there is some issue with #3, is there any hope that it will seal? At one point that cyl siezed, so there may be wall wear. Does anyone think that with Total Seal, it will fix that one cyl, and bring them all to the same level? Also, if anyone is wondering, I am 8.6:1 and pretty sure I have a cam timing issue (7" Hg is a good sign, I think).

The compression wont match across the board. Cylinder wall to number #3 could be warped, or scarred. From what I understand you want an even compression across all pistons for a well balanced engine.......... Even if you used total seal, cylinder #3 will more than likely show a lower compression.....Then again I haven't used gapless rings, it could work out to be a miracle.It's a toss up what went under more damage? The cylinder wall or the rings?If you magnaflux the block you could really determine where some errors occurred and if it would be a wise investment to use total seal.

[Chezedik]

I will roll it and see. I did not have anything wrong with the walls, and I checked the end gap on all of the rings. I wish that I would have wrote it all down. I don't know why just one wall would scar though, from seizing. Since it actually threw a rod, the crank took all of the damage. Maybe valve clearance isn't right yet either, I will see.

[Bigvinnie]

Heres an update on the total seal rings...I spoke with a few people that have actually installed them (gapless rings) in to 350 chevy blocks. They work great, but too great from what I understand. It increases bottom end pressure to the crank case and an ultra light motor oil needs to be used either a 0w-30, or a 5w-30, it doesn't have to be synthetic oil either, just a really light oil..... There is very little play or tolerance when these rings are installed, and there is lots of compression. I was told that the block needs to be magnufluxed to guarantee a good solid compression or the investment is worthless.

[sxseguy]

Some additional info for everyone:

You can get them at good old summit.com. Search for TSR-M0664 (gapless top ring sets - $175) or TSR-T0664 (gapless second ring sets - $137). They come in standard, +.020 and +.040 sizes.

Gapless top sets (includes gapless top rings, conventional middle rings, and stainless oil rings)

Gapless second sets (includes conventional top rings, gapless middle rings, and stainless oil rings)

But... the Wiseco pistons use 1.0, 1.2, 2.8 mm rings instead of the standard Nissan thickness of 1.5, 1.5, 2.8 mm. So, the standard KA rings won't work with these and some other aftermarket pistons.

Maybe other piston owners can confirm ring thicknesses for their pistons. I know the Ross uses non-standard ring thicknesses. Anyhow, I did some more research and found other sets that might work.

Gapless top set for +.5mm overbore, 1.0, 1.2 2.8 mm ring set - $49 (single piston set, four required, so $196)

Gapless 2nd set for +.5mm overbore, 1.0, 1.2 2.8 mm ring set - $136 (full set of four)

I still have to confirm that these will work. I'm not sure of the groove depth and ring depth matching yet. These particular rings are listed for a Honda XR500 motorcycle, but the dimensions check out so far.

[artemous]

OK OK have to jump on this one.

I've been preaching Total Seal for years. Look up the patent uspto.gov and notice my dads name on it as he did the patent work and is a large shareholder. The company is located in Phoenix, Arizona near Deer Valley Airport.

As for tech, the "total seal" total seal ring, usualy the second, is groved to accept a chrome faced steel insert. The insert's gap is placed opposite of the main rings gap. The top ring can be made from many different materials, have different coatings, and have many different cuts. They can make custom rings of almost any configuration. While it is not feasable to make a .001 over ring, custom fit rings are available that are several thousanths (five or ten thousanths) over to custom file to your own gap settings. They sell a special ring filer.

The TS1 set has a plasma moly faced ductile iron top ring (lightened in the TS1R set), total seal second, and a std tention oil ring. The "gold power" oil ring is lower tention but with the same oil control ability.

The TSF is the std set for the imports. It has a plasma moly or chrome facing option. Chrome is best left for dirty operating conditions such as off road.

There is also spring steel material that MAY be available for the top ring.

As for sealing, they seal much better. My Corvair had NO measurable leakdown. They can increase idle vacuum and make worn valve guides aparent. As for increased lower end pressure, Less blowby should mean just the opposite.

The total seal rings are used in top fuel cars so don't worry about them breaking. When they're broken in the "insert" ring contacts the cylinder wall with a chrome face and seals with the main ring, hence low friction.

One final note, as the total seal ring wears, like all piston rings, it DOES NOT increase ring gap. Blowby does not increase unless you ingest dirt , seriously overheat them, or something major like that. They are worth the extra bucks.

If you're realy serious about ring seal, top everything off with a nice set of centrificaly spun ductile iron sleeves such as from Darton.