Iv done a few STD bore wiesco stroked pistons lately running 4.5tho p to bore and have found the bottom rings are around 28tho ring end gap out of the box. Can I just get rings to suit 20tho over pistons? Or even use the 20thos when I do 10tho over pistons? I want to drop the bottom ring gap to about 24tho

Is there a reason you want to go against the recommended specs of the manufacturer?

With a stock 85mm (3.346456692917 inches) and their blown race recommendation of .0063" for every inch of bore for the 2nd compression ring, you end up with .021082677165377 or 21 thousandths.

That brings up another issue. These rings are made to fit tight and be "filed to fit", so why are your rings coming up so wide/loose? Seems like your bore is larger (increased PTW over recommended specs due to high boost?) than intended, which should increase the end gaps.

If everything checks out on your end, you can always call Wiesco (Brian Nutter) and talk to him. He will provide you with a solution.

Robert

I'm running alot more piston to bore clearance because that's what iv found works for 450wkw+ on a mustang dyno. And that's the same reason I run bigger ring gaps. I realise they are file to fit but when they are too big out of the packet there's not much you can do. I'm on the other side of the world so ringing wiesco is a pain in the ass with time zones and I know a few guys on here run up to 5tho p to b.

I looked over the location. Since time is an issue you can always shoot them an email.

http://www.wiseco.com/ContactUs.aspx

It only makes sense that the .010" and .020" over rings will be longer making the end gaps shorter when compressed into a smaller bore. I have no personal experience with this nor do I know anyone running it this way but an email to the link above will ensure this is the correct solution.

Robert

Wiseco rings are not file fit. they design the setup for someone running a stock setup, so then when you open up the ptw to what it needs to be the rings are too small.

OP try and see if you can get a set of rings from another brand. I ran JE's in my last motor and the rings were file fit. You want a gas nitrided top and and iron second ring.[DOUBLEPOST=1411743778][/DOUBLEPOST]http://www.jepistons.com/Catalogs/ProSeal/RingSearch.aspx

Wiseco rings most definitely ARE file-fit. I've had a few come through over the years where the second ring gap was too big which required them so send us replacements. Conversely, I've had them overlap by .010" or .020". This is why it's good practice to mock everything up prior to assembly.

Just because parts are new doesn't mean they're good; it just means no one has figured out what's wrong with them yet

Are you Sure? They may be called file fit, but they certainly don't need it unless you run huge gaps. I've never seen a wiseo come with rings that were on the small side. They are always on the big end of the gap range. I've put a lot of them in various situations, and they are all like that.

The 85.50XX rings that my pistons used were outside of the range they reccomend, and that was with the .004" ptw they reccomended.

My JE rings needed filed to get to the small end of the range, with the same ptw clearance.

Yep, 100% sure. Every now and again I'll come across a set where the second ring is on the high side but not often. The top rings almost always have about .005" out of the box. If you're consistently encountering this problem then I would question the accuracy of your equipment or perhaps your cylinders are being machined too large.[DOUBLEPOST=1412196389][/DOUBLEPOST]

bastarddsm said:

You want a gas nitrided top and and iron second ring.

Click to expand...

Just like what comes with the Wiseco's....... They use a gas nitrided top and phosphate coated iron second ring.

We must not be getting the same ring sets. A cylinder would have to be like .005" to big for that much difference.