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I just got my 460 back from the machine shop, and got the crank installed yesterday. I also installed the rings on the new pistons and was wondering about the orientation of the rings. I am using Mahle rings, and the installation instructions they supply say to install the top segmant of the oil ring about an inch to the right of the joint of the spacer-expander, and the bottom segment about an inch to the left of the joint. What I need to know is where to orient all of the rings before installing the piston in the cylinder.
If it matters, this motor is out of my '83 F250.
Thanks for the help!
The '81 factory shop manual shows the following for the 460, with the piston pin running from 12:00 to 6:00 and the front of the piston at 6:00:
Oil ring segment 1" CCW of 12 o'clock
Oil ring spacer at 12:00
Other oil ring segment 1" CW from 12:00
Compression ring 150 degrees CW from 12, which puts it 180 degrees from the oil ring segment's end
Other compression ring 150 CCW from 12, which is again 180 from the other oil ring segment's gap
What it doesn't say is which compression ring goes where, so I'm assuming that doesn't matter. And, neither of my small-block rebuild books tell which compression ring gap goes where so it must not matter.
Thanks Gary. My Haynes manual says something totally different. I believe I'll trust your shop manual before the Haynes. I'll see if anyone else chimes in with anything on the compression rings, and if it makes a difference which one goes where.
That reminded me that I have a Haynes - Ford Pickups & Bronco, 1973 - 79. It shows something far different as well. It has the front of the piston at 9:00 and the oil side rails 180 degrees from each other at about 10:30 and 4:30. And the compression gaps are 90 degrees from that with the top gap at 1:30 and the 2nd ring's gap at 7:30.
I would trust the FSM. It fits nicely with the two How-To books I have on the SBF. And, it agrees with the diagram that came with my Perfect Circle ring set for the 351W I built.
Edit: But, I would absolutely agree that you should wait for more to chime in. You don't want to be second-guessing this when the engine is together.
The main thing is that none of the gaps are in the same position across all of the rings so that there is no chance of compression loss, It always reminds of reassembly/insertion of the bolt back into the carrier on an M-16 after cleaning. That point was stressed heavily at Parris Island... Line the gaps up and it wont cycle.
The main thing is that none of the gaps are in the same position across all of the rings so that there is no chance of compression loss, It always reminds of reassembly/insertion of the bolt back into the carrier on an M-16 after cleaning. That point was stressed heavily at Parris Island... Line the gaps up and it wont cycle.
Funny...I was thinking about rifle bolts (AR-15 in my case, since I don't get to play with the good stuff) as well. My understanding has always been since the rings are compressed once the bolt goes into the carrier, the gaps are closed. And if the gaps aren't closed, then you're in trouble no matter how the gaps are aligned, since you're alerady experiencing blow-by.
Seems to be the same situation here...the orientation would only matter if you're experiencing blow-by, and in that case you're already experiencing ring failure.
I just spoke with the guy at the machine shop, who I know really knows his stuff, and he pretty much said the same thing. Just make sure that the gaps aren't lined up. I think I will do it according to the shop manual though.
Thanks to everyone for the help!
There are more pictures in my gallery, they're from the 400 that was in my truck. It was "rebuilt" by a PO but started making a puff of blue smoke on startup a few years after I got it. Nobody knew what "rebuilt" meant, so I started taking things apart and hoping for something simple like valve stem seals.
Ha!!!!!!
That piston wasn't the only thing I found, the guy really loooooooooved RTV and tried to seal the head gaskets with it.