nice build! so how do you know?? lol I am definitely going to go a little more on the loose side as well.

 

Picture fail? I don't get ur fancy interwebz speak...







later, x

 

i got some very useful information for you i just had my car tuned saturday on 18psi with vf39 have 1100 miles on my new motor after tuning did couple pulls and car started running like shit lost over 50% compression in all cylinders it went from 190psi to 150psi then to 90psi later that day. so i pulled the motor today and and disasemble it come to find out my piston to wall was too tight and when the piston expanded started rubbing flat spot on top side of the side skirt on all the piston just from that 1st thru3rd gear pull. My piston to wall clearance was .0035 same as yours. so I suggest to is, you is should go .005 to .006 piston to wall dont want to see same thing happen i can post pics if you want too see

 

Sadistically, pics would be nice- sorry for your loss...

As far as my situation, we honed out every cylinder to the "big" factory bore spec- they all cleaned up there at 92.015mm- 3.6226in, and sent off a factory piston to Diamond and had then machine custom ones to fit that bore. They calculate the p/w clearance in their end of the build. My measurment of .0035 was with a bore gauge and calipers and it's the tightest I saw. I didn't ask for anything specific.

The 257's have a bigger bore and should "theoretically" need to run a higher p/w because of expansion ratios and stuff.

later, x

 

ughhh its very hard to get people to understand i refered to my tuner that builds dsm race motor 2.0 for a living and he recommends nothing less than .005 piston to wall unless running factory setup cause the pistons are designed for stock application not for higher hp goals if you plan on reving higher than red line and running 500hp 600hp engine you definitly need looser P/W as soon as that piston starts heating up from that boost its bad news.

 

More updates:



I went by the factory cam cap torque spec of 14.5 ft lbs, and here is what happened to the front cap bolt:



14.5 foot pounds MY ASS!





Bottom is done...Now to the front:





Timing belt wasn't as difficult as I imagined. I did have a buddy hold things though...

More to come.

later, x

 

bad bolt? arp should be used

 

its 7ft lbs!!!!!!!!!!!!!!! the rear caps are 14.8 fronts are 7 look at the bolt diameter they are different sizes BTW you replaced the 17 case bolts correct cause you cant re-use them

 

I re-used the case bolts. If I had the money I'd arp everything, but that isn't the situation.

later, x

 

i have the torque spec for the sti and mine says 7 ft lbs and 14ft lbs on the other 2 caps it makes sense cause the bolts are smaller.....