AOS Failure: what breaks first?

[911monty]

What no paranoia induced "what if" scenarios.......Too bad it's the season for a good scare HAHA.. so here goes. In case you missed this hair raising tale in your search read the attached. My post #31 and several later asks to check what the OP amazingly discovers in his second thread. For your Halloween amusement I present

AOS - Question

CamShaft Timing


PS I do have a question for data. Did you get the clutch released in the spin or did the engine possibly spin backward? Thanks

[maytag]

Originally Posted by 911monty

What no paranoia induced "what if" scenarios.......Too bad it's the season for a good scare HAHA.. so here goes. In case you missed this hair raising tale in your search read the attached. My post #31 and several later asks to check what the OP amazingly discovers in his second thread. For your Halloween amusement I present

AOS - Question

CamShaft Timing


PS I do have a question for data. Did you get the clutch released in the spin or did the engine possibly spin backward? Thanks

aaaahhhhhh......
So, I can't even picture yet where these scavenge pumps are, and how they sit. I'll have to become more familiar. If one or both are bad, will I see that in a test of the AOS with a manometer?
And I'll definitely be checking the cam positions. Too easy to check to not do it....

Thanks Monty!

[911monty]

Originally Posted by maytag

aaaahhhhhh......
So, I can't even picture yet where these scavenge pumps are, and how they sit. I'll have to become more familiar. If one or both are bad, will I see that in a test of the AOS with a manometer?
And I'll definitely be checking the cam positions. Too easy to check to not do it....

Thanks Monty!

You'll find the scavenge pumps the same place as the cam plugs. The pumps are driven off the exhaust cams. Bank 1 pump is toward the rear and bank 2 is toward the front. They are held on by 4 bolts, replace the bolts with the o-rings.
As far as identifying by manometer, not likely. But what happens if one fails is the head fills with oil and reduces the vapor space allowing oil to be pulled from the head into the vent pipe and into the AOS sump. There are swirl vanes in the sump of the AOS which will centrifuge out small amounts of oil in vapor, but will become overwhelmed by liquid oil from lack of retention time..