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Currently going through a forged engine assembly with the below specs:

- blocked bored to 74.5mm and surface decked

- wossner forged pistons

- acl bearings

- scat rods

- arp main cap studs

the block has been assembled using engine assembly lube and following tightening torques provided by arp. The assembled crank on block rotated very easily however when the rods and pistons were installed, it seems that there is too much resistance to turn crank.


does anyone have an approximate value for torque that would be required by a torque wrench to rotate an assembled block? Could this be due to resistance of piston rings on freshly bored and honed bores? Which would then become smoother once piston rigs are seated in?

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It shouldn't need much more force then what is required when rotating without the pistons and rods.

The extra resistance will be the rings,

main thing it should feel consistently smooth after initial force applied.

If you feel its too much you will have to bactrack.

using the arp studs with higher torque value in comparison to factory spec can put your mainline out of roundness. The cylinder block would require align honing with the arp fastners to get it back concentric.

Wd40 the bores and see if feels better.

Good luck.

Edited by GP82
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