I have 87.5 mm wiseco pistons I just wànt to double check my calculations for ring gap

 

Wiseco spec for street moderate turbo/nitrous is as follows

 

Top ring calc 0.005

2nd ring calc 0.0055

 

Now take bore size x ring calc

 

For top ring bore is 87.5/25.4 to give fig in inches

 

So 3.44488x 0.005= 0.0172"

 

2nd ring

3.44488x0.0055=0.0189"

 

So top ring end gap 0.017

2nd ring gap 0.019

 

 

Does that seem right?

Checked the top ring with out any filing and it's 0.009" so I have to file 8 thou off to get 0.017"

Edited November 30, 201411 yr by hellraiser

Figures look correct to me.

Are you going to use a ring gap filing tool?

Good little diamond file with the ring set in the vice between 2 pieces of thin wood is how i set my gaps Gary...dont need all the fancy gizmos iff you take your time. 4 thou either side is nothing.

I have bought new diamond files specially for the job ;-)

Got to be worth considering, surely?

 

http://www.ebay.co.uk/itm/Piston-Ring-Gap-Filer-tungsten-carbide-cutter-tool-Any-diameter-piston-ring-/261369170723?pt=LH_DefaultDomain_3&hash=item3cdad10b23

 

After all, you are going to a lot of trouble and expense.

Ha'p'orth of tar and all that.

this is the first top ring I have tried. Needs 0.008" removing to get to the required 0.017" gap

[ATTACH=CONFIG]84244[/ATTACH] this is the first top ring I have tried. Needs 0.008" removing to get to the required 0.017" gap

 

has that block been through the bath at the machine shop Gary...water jackets look clean:thumbup1:

No Brian, I spent a good few hours with jizer degreasent and a pressure washer cleaning it very thoughly. Then oiled all the important surfaces. Then stored inside two bin liners on its stand.