No oil pressure after head swap m20 325ix

[ForcedFirebird]

Just trying to picture how one can make that mistake....still don’t get it. If you rotate ex shaft 180 so holes are up and slide in IN which the key slot aligned to the center, rockers won’t alight as shaft has rocker holes and clips spaced out so the cyl 1 IN goes first or cyl 6 EX goes last. IN and EX shafts are the same. If you install EX shaft in IN which front key slots inward, piling holes will remain on the bottom ...EX and IN shaft are the same. Am I missing something???

Yes, missing something. The rocker shafts are symmetrical, there is no left/right. If you slide them out of the head and keep the rocker retainer/key grooves together, and simply flip the pair over, the retainer/key grooves and will still face each other, but the holes will be up - then rotate the pair of shafts 180° longitudinally to the head and the rockers will be in the correct position. The retainers/keys will still be facing each other, but the holes will be facing up.



Maybe it doesn't make sense in text, but believe you me, I have had heads come in the shop that were installed wrong. I had to pull the rocker shafts and correct the issue - not a fun job with the head installed and on a street car with a condenser etc. In the race cars, we drill the firewall in case a rocker breaks at a race, we simply slide the shaft aft to replace the rocker in a hurry if it's a rear-most rocker, and remove the radiator if it's a forward rocker. The shafts will even slide out of the head through the cam gear as long as you have the spokes in the correct position.

[zaq123]

Yes, missing something. The rocker shafts are symmetrical, there is no left/right. If you slide them out of the head and keep the rocker retainer/key grooves together, and simply flip the pair over, the retainer/key grooves and will still face each other, but the holes will be up - then rotate the pair of shafts 180° longitudinally to the head and the rockers will be in the correct position. The retainers/keys will still be facing each other, but the holes will be facing up.



Maybe it doesn't make sense in text, but believe you me, I have had heads come in the shop that were installed wrong. I had to pull the rocker shafts and correct the issue - not a fun job with the head installed and on a street car with a condenser etc. In the race cars, we drill the firewall in case a rocker breaks at a race, we simply slide the shaft aft to replace the rocker in a hurry if it's a rear-most rocker, and remove the radiator if it's a forward rocker. The shafts will even slide out of the head through the cam gear as long as you have the spokes in the correct position.

They are not symmetrical:


IN #1 cyl rocker hole = EX #6 cyl rocker hole; IN#6 cyl rocker hole = EX #1 cyl rocker hole

IN#1 rocker hole/clip is not in the same spot from the center of the shaft or it's edge as EX#1....

look at the pic, rocker holes are not symmetrical. If one would use this shaft in the pic for IN, left side is the rear (#6), right is the front. If one would to use it for EX, left side is the front, right side is the rear. Any other arrangement and the key ( thingy in 2nd pic) won't be able to be installed as its slots will face outward. If you look at the 1st picture of the shaft, the key slot is not visible, it's on the other side, oiling holes are the big ones on the bottom

[ForcedFirebird]

Welp, I eat crow.

I still have the shafts from that botched job, will have to take pics for ya. Memory is slipping. The owner obviously installed them incorrectly, they just grooved the shafts all the way around for the rocker retainers. derp.