Wiseco standard bore piston ring gapping

[97slvergsx]

Hi everyone, I'm new to this site and i've searched around but I kinda find an exact answer i'm looking for. I had a stock 6 bolt wit bc 272's and a 50 trim making 359 to the wheels on a dynojet. now that winter is approaching I am doing a fully built forged internal setup and i bought everything already and have a machined standard bore block. I have wiseco 9.1 compression pistons standard size on eagle rods. I plan on boosting the car 30+ psi on e85 next spring and i wanted to know the proper gapping on the top and second ring. I saw someone say the .20 on the top ring and .023-24 is good on the second ring for up to 30psi. are these good numbers and if they are are they safe if i wanted to run lets say 32-33 pounds of boost. any help I would greatly appreciate it. thanks

 

[cpoindexter]

wisecos come with a formula that you follow depending on your setup. you want high boost so you would follow the track/street forced induction numbers, then you multiply the bore size in mm by the given number for your setup

 

[BogusSVO]

Should be a peach colored sheet in the box with the pistons

( I know I have posted this in a few threads)

Bore x (wiseco factor)

Stock bore on a 4g63 is 85mm or 3.346

To convert from mm to inches 85mm x .03937 = 3.346

3.346 bore + .020 over bore = 3.366

Wiseco recomends "street-moderate turbo"
top ring factor .0050
2nd ring factor .0055

so 3.366 x .0050 = .01683 or .017 for top ring
3.366 x .0055 = .018513 or .019 for the 2nd ring

For 30psi of boost these are too tight..

Now Wiseco "Blown Race only"
Top .0065
2nd .0070

3.366 bore x .0065 = .021879 or .022
3.366 bore x .0070 = .023562 or .024

The common gap I have seen used on tuners is the .020 top and .024 2nd ring

Depending on how well you can tune, should help you decide on the ring gap.

If you are a good tuner then you can run a little tighter
If you are new to tuning, then run a tad looser.

The reason for this is lean condition safty, the rings will expand more when lean, going looser allow the ring to expand before the ends butt then flex then crack the piston ring lands.

 

[97slvergsx]

excellent thank you guys so much for the help. i really appreciate it!