is 40 thou over to far over to run big boost through ? does any one on here use this?

how much power you want ? 40 thou does thin the cylendar walls alot i wouldnt recomend massive power on a 40 thou block if your aiming for more then 350 k/w i would suggest finding a 86 ml and going 20 thou

pffft, 40 thou over is fine, iv seen rb30's runing 1mm over, big boost application? i probly wouldnt go above 80 thou

Quote: Originally Posted by skidmarx pffft, 40 thou over is fine, iv seen rb30's runing 1mm over, big boost application? i probly wouldnt go above 80 thou Ummm... I wouldn't be using 80 thou either LOL!!!!!!

Quote: Originally Posted by skidmarx pffft, 40 thou over is fine, iv seen rb30's runing 1mm over, big boost application? i probly wouldnt go above 80 thou Um ok you dont know what your talking about. 40thou is slightly more then 1mm. 80 thou is therefore more then 2mm. Wouldnt want to be doing that now would you?

Most RB30 piston kits go to only 40 thou and some to 60! I know of many boosted engines running 40 up making big power with no issues!

80 thou rofl fark dude go kill yourself... as i said its ok but i wouldnt recomend aiming for more then 350+ on a 40 thou block the walls are thin sure you can do it but i wouldnt do it for a customer is the best way to put it just for reassurance...

most aftermarket pistons, come as either 0.020" or 0.040" 0.5mm or 1.00mm in metric, but as stone racing said its much better idea to keep your bore sizes as small as possible when chasing big hp numbers, especially whilst rb30 tend to split bores when producing big power, although it might not seem like much every thou counts. Also dont forget when you go 40 thou over then plus your piston to bore clearence which is usually 0.004" thats on top of your 40 thou as well. Alot of people have different opinions about it bit i tend to agree with stone racing.

yea its common sense really. 1mm is a hell of a lot in engineering terms.

40 thou is the most you should use