Total seal gapless second ring install

Hey guys, working on a friend's engine and having trouble with end gap on the backup ring. Gapped the top rings and second top rings, but how do u check end gap on back up ring? To small to square in cyl bore! Oil rings were perfect gap out of the box. Never used TS gapless rings before and no info on installation paperwork. Any info would be helpful . Thanks cory

It is possible I do not know which ring you are refering to but here is my night mare story. I used wire gages to do mine. I had to have the trick of the week when they came out. I was running alcohol way back then and figured it would help keep it out of the oil. The problem is a second ring zero gap will not let the top ring function correctly in my engine above 6500 rpm. It would go into ring flutter and pressurize the crank case blowing out the valve cover gaskets and intake end gaskets. In addition to dry sump and vacuum pump I had to plumb back into the headers for when it overcame the vacuum pump. Got them out as soon as possible and all was well. I probably would try one in the top ring if I was still running alcohol, they work there. Mark J

I have ran several sets of these gapless top rings, and they are very much worth the effort in my opinion. As Mark J pointed out, when these were used in the 2nd ring application, many times, the top ring would flutter and let pressure get past it.
Total Seal did a lot of testing and their homework on the issue, and moved the gapless position to the top ring.

I have very carefully placed the thin rail ring into the bore to check them and found that they did not need any extra opening up, but if you have some that are in need of more gap, then by all means open them up.
If you are using a flat top piston, put the piston in the bore, about a 1/2" inch down, and then put the rail ring in the bore, using the piston as a stop, then very carefully lower the piston away from the ring and take the measurement.
The thin rail ring should have the same amount of gap that the main ring has, or within .002" thousandth's of it.

Thanks for the info guys, the machine shop talked my buddy into them, after reading what you all said. I remembered the box they were in was pretty ratty looking ( old ) !!! I will tell him to get a new set of conventional rings. He will be spinning it around 7500 rpm. He will squawk about spending more money. But that's racing. Thanks cory

You can use the top and the oil ring