do i gap standard size npr rings?

[joe sobo]

i am doing a stock rebuild due to a spun bearing. so i had the engine completly check and within spec. so i bought npr rings for a standard bore, but the box does not say how much or to even gap them

 

[Jeff99GS]

You are going to have to install them in their respective cylinder bores and measure the gaps with a feeler gauge. We can't tell you if they are the right size without measuring them.

 

[joe sobo]

well, my problem is that i put the lower oil rings in the cylinder just to see, then i tried to fit the center peice of the oil contol ring in to the block. i can't it seems too big for the bore. even though the box was never opened till i did. so then i tried to install the two oil rings onto the control ring on the piston, and it seems as though the control peice needs to be cut some.? so then i take just the center peice and slip it on the piston and squeeze it till both the ends butt together with out over lapping each other, and it is just too big. there is so much slop
are these able to be cut? the rings in the block seem to be fine. i cant seem to find my feeler guage so i will buy one tommorow

 

[Jeff99GS]

They are hard to get in with out a piston ring compressor. Just check the #1 set of comp rings and the #2 set of rings. You don't have to gap the oil rings.

 

[redyute1]

If it says standard bore then there is no need for filling,unless it specifically says file to fit piston rings like the wisco's

 

[MichaelSuch]

The Wiseco's I purchased came pre-gapped. I checked them anyways, as you should with any manufacturer. It's like plastigaging bearings to me. It's something that needs to be done to ensure proper clearances otherwise you will run into more problems later down the road. There could've been a manufacturing defect as well where the rings are not the right size.

 

[Jeff99GS]

Yes even if they are pre-gapped you should check them. Some people like to run Larger than stock gaps for HIGH boost engines too.

 

[toofast82]

I would definitely check them just to be sure, it only takes a few extra minutes

 

[DSM pHrEaK]

But does anyone know what the gap spec is?

 

[Jeff99GS]

The stock specs for the #1 top compression rings are 0.009-0.020 inch

#2 Intermediate compression rings 0.019-0.031 inch

#3 Oil control steel ring 0.009-0.026 inch

I set my top ones at 0.017 and the 2nd set at 0.021 They say its better to have a lil more gap for higher boost. I don't really know why tho?

 

[matt98eclipse]

In my build that im in the process of i ended up using the "standard NPR rings" I did not have to gapped them. They were already within specs. Just make sure you install them the right way.