seal of piston rings

Do piston rings seal better when new or do they seal better after they ran after lets say 2000 miles the reason im asking is that im doing a leak down test block fresh out the machine shop with file fit rings

they need to seat first.

same

what if they were 80%  .019 top a bottom

New rings will have to seat to the cylinders before you will get a true reading I just about bet the leak down test will fell if the rings have not been seated yet.

man I sure hope so some thing like this can drive a man crazy all the way from the engine stand to the hood

did you do a leak test on the valves before assembly to see if they were seated properly?you didn say how many miles you had on the motor.

brand new motor fresh out the machine shop $1700 worth still on the stand

You need to let that NEW engine get really good and Hot at least 200/210* then let it cool down. They will seat.  

update I returned that cheap leak down junk scrap of a tool got a new one from NAPA boy did that make a differece 23%-17% across the board  you live and learn DO NOT BUY CHEAP TOOLs

I tell my guys to never do a cold leakdown test anyway. The results from a cold test are as useless as tits on a boar hog. Always do a leakdown test with a very warm engine.

Hope this helps,
Charlie

c.evans wrote:I tell my guys to never do a cold leakdown test anyway.  The results from a cold test are as useless as tits on a boar hog.  Always do a leakdown test with a very warm engine.

Hope this helps,  
Charlie

  C.Evans how much of a difference is there between a warm and a cold engine by your experience when doing a leak down test 5% 10%

The percentage varies, but I've seen it be over 20%. Couple of my guys have called with their panties in a wad, telling me it's got 18% leakdown or some number, and then when they tell me it was cold, they get a butt chewing for even bothering me. I tell them to do it hot and then call me back,,, when they do, they're are kind of sheepish because now it's 3 or 4%.

Charlie