oil ring support rails / some quests

[german4inline]

Guys,
I´m going to source oil ring support rails for my small Renault Alpine engine. In Germany or even Europe, they are not known at all....now I found some at CP-Carillo with 3,149" bore. They would be ok, but what I´m wondering about, they are 0,126" wide ( 3,2 mm) , I´ve hoped for just half this figures….they might be f***ing big weight. I´m pretty sure that 2 mms or maybe 2,5 would be ok as well. Does anybody know if there are somewhere rings with smaller height available? The problem is the small bore of 3,15 ", ist just Mickey Mouse for US conditions….it took some time to find some at all however

[BillK]

How deep is the oil ring groove in the piston ? I would think that you need the support rail to be almost as deep ?

How much weight are you trying to save ? I figure the difference between the 3.2 mm and the 2.5mm is only going to be about a gram.

I wonder if Wiseco might have something for one of the motorcycle pistons they make ?

[cjperformance]

The oil support ring in most cases needs to be the full depth(or just less than) of the oil ring groove

It needs to be a good fit and will need to be expanded from its natural position to correctly fit the piston.

It needs to spring back/reduce in diameter so that it is snug in the bottom of the ring groove so that it cannot float side to side and touch the bore.

Check ring groove chamfer is not going to contact the I.D. of the spacer.

In any case where the oil ring groove is not continuous, ie- it may have a pin bore intersect with it, the spacer must have some form of notch/pin/dimple etc to stop it from rotating and having its gap align with a non supported section of oil groove.

Weight wise, my 1st concern is simply that the support spacer is fitting and doing its job correctly! 2nd if weight really is an issue, take it from the piston/pin/rod (or a little from all) in a suitable location.

[Mark O'Neal]

I weighed a 3.500 Bore support with a .168 radial dimension and came up with 7 grams. Take .300 off if it and it probably weighs 7 grams.

The weight difference is would be irrelevant. The variable in the weight of oil slinging around probably weighs more than this.

[german4inline]

After your replies, supposedly I have confused the height of the rail with the radial width. Do you refer the 0,126" is the radial dimension? This would be ok, I first confused it with the axial height of the rail , oops…..I thought you could use it as a circlip for a truck propshaft…..


@Mark O´Neal: If you have a 3,15" rail available, could you measure the axial height of it? There´s no dimension refered in the catalogue.I´m pretty sure that yours is a CP-Carrillo item, your dimensiones are exactly those from their catalogue. I asked them for the weight, they told me as well 6 gr. what´s completely ok. I calculated a rail with a height of 3,2 mm with about 11 gr., I was more confused about the big height as about the weight.

I would estimate the rails height at 2 mm max. Thanks a lot you guys

[Mark O'Neal]

The axial dimension is pretty much standard at .030. I don't use any that small, though.

[german4inline]

@Mark: .030? Crazy, thats really small…..I think they do so to be able to press the dimple through the thin wall....Do you know if there are any other manufacturers who are offering 3.15" rails which might be a bit thicker ? I´m worried that those thin rails will be distorting and hinder the movement of the oil rings. Unfortunately, I never saw an oil rail, in Germany absolutely unknown. Are you dealing with small engines with 3.15 bore, ist unusual for US engines…..

[german4inline]

Nobody knows where to source oil rails for 3.15" bore unless CP-Carrillo ?

[Mark O'Neal]

@Mark: .030? Crazy, thats really small…..I think they do so to be able to press the dimple through the thin wall....Do you know if there are any other manufacturers who are offering 3.15" rails which might be a bit thicker ? I´m worried that those thin rails will be distorting and hinder the movement of the oil rings. Unfortunately, I never saw an oil rail, in Germany absolutely unknown. Are you dealing with small engines with 3.15 bore, ist unusual for US engines…..

You spend entirely too much time worrying. We use those in Small Block Chevys at 60+ lbs of boost, with much larger pins than you are running.

If you find them, it will be from someone that uses them in motorcycles. 3.500 is as small as Smalley makes them.

Go to a manufacturer...Total Seal might be willing to come up with something as they do make a 3.150 ring set. Try kevins@totalseal.com.

[german4inline]

Thanks a lot, Mark, I´m going to contact totalseal. I´m not worried about the loads, as I said, oil support rings are entirely uncommon in Germany. I would have already switched to 2 ring pistons to overcome that problem. Supposedly these are uncommon in USA in turn

[Mark O'Neal]

Thanks a lot, Mark, I´m going to contact totalseal. I´m not worried about the loads, as I said, oil support rings are entirely uncommon in Germany. I would have already switched to 2 ring pistons to overcome that problem. Supposedly these are uncommon in USA in turn

They used to be common...I've even built them with two 1/16 rings in a double wide groove. We don't use them because motors make more power without the oil in the combustion chamber.