Was wondering how big you can bore a stock sleves..... my friend said 87mm is safe when you use forged pistons and drill out the oil journals and use a ITR oil pump...... anyone have advise for me I need to hit 250 ttws. Thanks Rob

 

You'll be posting how you cracked your sleeves not too long afterward. If you can't afford to do all motor right the first time then my advise is to just boost your motor.

 

87mm huh LMAO 84.5 if you need a rebore but otherwise stick with 84. oh yeah and taking out a perfectly good oil pump and putting the exact same type back in because you want type r parts is dumb. all b20's come with the same oil pump as a type r

 

chad from merrit island ran a 85mm bore on un-sleeved block, it was fine in his pro all motor car!


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We ran 85 mm for over 2 years with no problems.