Hello I am new to the site, I have a question. I am converting my 502 mag which was carb ran, I now am installing an EFI set up(early 90's) on the motor. I can't find where to attatch the tubes from the valve covers for the crankcase ventilation, there is no spot on the flame arrestor. Need help,
thanks Steve

It may not use tubes..just buy some crank case breathers that fit in the valve covers..a good SS mesh one costs about $10 at PepBoys or Oreilly's

not CERTAIN thats gonna work... if its the mpi system its a closed system and can't vent to atmosphere without sealing up the ports in the throttle body... my stuff is later than what you are talking about and i could be wrong but but i don't think any of the efi stuff vents to atmosphere from the factory....

Well when I look on the electronic parts disc it shows both side being vented into a baffle then up via another tube. I just don't see where it goes. It is a 93-95 EFI set up.

that tube will go to a port in the throttle body, i am almost certain. now.... on mine i seal up that port and vent to atmosphere because i don't like the oil vapor in the intake... but if you do that you HAVE to seal that port or un metered air will pass...

I belive the HP500EFI is venting to the atmosphere. Please correct me if I am wrong.

I am at a loss, I know it goes to the plenum some where, as the diagram shows,however where. When I got the set up, it had a plug or fitting missing in the front of the plenum, right above the thermostat housing, any ideas what goes there? Any help would be helpful, Thanks Steve

HP 500 vents to the atmosphere. BOB

mine goes right up under the throttle body / air cleaner.

http://www.mercruiserparts.com/Show_...D+ROCKER+COVER

My 1996 Gen VI 502 MPI has a small tube from the right valve cover up to the screen on the bottom of the flame arrestor. #29 in that parts diagram.