Bolts VS screws on valve cover

[Anonymous]

Just wondering if these is a reason other than looks that four of the outside edge fastners on a valve cover would be screws instead of bolts.
According to the fiche thats how it's supposed to be. The bolts have flanges as do the screws, the same size, so I don't think it has to do with amount of holding surface.
I don't see a mechanical benefit to it??

[Anonymous]

Maybe the engineers had a little too much saki that day. I say dump the screws and replace them with bolts.

[massakins]

Sometimes screws are used instead of bolts to reduce the potential torque that can be applied to the fastener. Excessive torque can break the fastener, strip the threads or deform associated pieces. A second reason to use a screw instead of a bolt would be because there is limited swing for a wrench; not in this case however. I forget what exactly these screws thread into but would be very careful to follow the torque specs in the service manual here. Ride on.

[Anonymous]

The screws in question thread into the the top of the outer head nuts. They also have washers which (supposedly) must be changed every time the screw is removed.