Strange setup on Detroit engine

[CDB101]

I have 4-53t's and notice something that seems strange to me, but appears to be factory setup. On the opposite side of the block from the blower is an access plate- I think this is a mirror image of the blower side so the blower could be installed on either side(?) On the access plate is a barbed hose outlet (1/2") to which a hose is attached and runs to a filter bowl on the back of the engine. (Note: this is not a coolant hose) The other side of the filter bowl the hose is run into the bilge. There appears nowhere else on the engine that this hose could run to. So wouldn't this hose be expelling my pressure from the turbo and blower on the scavenging cycle? Doesn't this plate allow access to the cylinder ports? Would I be losing HP? Feel free to correct my thinking here...

 

[yachtsmanbill]

Most in line and V DDs are of a siamese design end for end.. makes them that much more modular. The 453s are that, plus you can mount the blowers on the outboard sides for more centerline access. The vent you mention sounds like the notorious crap cans. There is probably an orifice in the line to reduce the air box pressure substantially.
If memory serves me the straight 53s dont have airbox covers, do they?? ws

 

[CDB101]

Each cylinder does not have a cover- the airbox cover on the opposite side of the block is in the center. The cover has the hose fitting outlet w/ hose coming off of it. Would this be an airbox drain tube? Would the filter itself prevent the loss of much of the airbox pressure? And is there anyway to change this setup? Thanks for any help...