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Post by Big-birds-ride on May 1, 2013 16:05:55 GMT -5
I belive that Dan has a corvair powered Bradley and some others have mechanical knowledge and backround. So here I am asking for technical assistance again ;D
A soon to be done project is going to be replacing the O-Rings on the corvair pushrod tubes. I have a couple of leakers and but one is getting really bad.
I have downloaded some tech advise on replacing the O-Rings and it does not seem like rocket science if one follows directions. What concerns me is that it seems best to start work on a cylinder by making sure it's on TDC as the valves will need to be adjusted after the process of disassembly to remove the push rod tube and replace the two O-rings on it.
With reverse rotation, how can I tell what the cylinder timing will be and in what order? I can follow the rotor and turn the engine main bolt (looks like a 1" or 15/16th socket). I would like to go into this with a little more confidence and less trial by error. I have two cylinders that I need to replace the pushrod tube O-rings on sooner than later. Might try to do them all, which is why I am asking about the firing order when in reverse rotation.
Any input will add to my knowledge base and be appreciated. I do know that only one set of pushrod tubes can be done at a time. Loosening too many bolts will likely cause a breach in the head gasket.
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Post by Dan MacMillan on May 1, 2013 21:30:21 GMT -5
Firing order is simple. This shows stock  You can use it for cyl location Firing order with a reverse rotation gear set is 1-6-3-2-5-4. With the cyl in question on TDC compression [check where the dist rotor is pointing], do the 2 tubes, then set the valve lash to zero {rolling pushrod between fingers till it cannot be turned} then an additional 1/2 turn of the rocker nut. Or with the engine running loosen the valve till it clacks then slowly tighten till it stops, then add 1/2 turn. |
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Post by Big-birds-ride on May 2, 2013 7:40:37 GMT -5
Thanks Dan !
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Post by Dan MacMillan on May 2, 2013 14:38:45 GMT -5
Don't forget that the dist rotates the same way as standard rotation.
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Post by Big-birds-ride on May 28, 2013 12:25:27 GMT -5
Spent the morning yesterday working on the drivers side push rod tubes. Took about 4 hours to do the one side.
Removed the headers as they block the valve cover.
Removed the lower shroud to access the pushrod tubes.
Removed the valve cover, cleaned it up.
Removed the rockers from cyl 2, removed the 2 Rocker studs, removed the the guideplate and removed the 2 pushrods. Carefully, using large plyers I pulled/twisted the two push rod tubes out of the block. Cleaned up the tubes.
Removed and replaced the O-rings from both sides of the tubes.
Re-inserted the tubes and tapped them into place.
Replaced the O-rings behind the rocker studs.
Installed the guideplate and rocker studs (35 ft lbs of torc), the push rods, the rockers and set the valve lash.
Repeated for cyl 4 and 6.
New valve cover gasket, a couple new valve cover bolts and the valve cover back on.
Back on goes the header with new gaskets.
Back on goes the lower shround after I clean it up... had to stop there to smoke some chicken and steaks, play pickleball, watch the Dodgers/Angel game... maybe finish the other side next Saturday.
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Post by Dan MacMillan on May 28, 2013 21:53:57 GMT -5
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Post by Big-birds-ride on May 29, 2013 12:05:39 GMT -5
I brought each cylinder to top dead center. While spinning the pushrod with my fingers, I tightened the rocker nut until I could no longer turn the pushrod, ie there was tension between the rocker arm and valve spring. I added 1/2 turn additional to the rocker nut. That should be pretty darn close to the correct adjustment. Adjusting the valves with the covers off would require removing the headers as well since they block access to the area. That would be a very noisey process to try and adjust the valves, might not hear the rockers tapping for all the exhaust noise. |
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Post by Big-birds-ride on Jun 6, 2013 12:22:24 GMT -5
Finished replacing the O-rings in the pushrod tubes and behind the guideplates on the engine. Had to idle the engine for 45 minutes for the lifters to fill back up with oil and quiet down. I heard one rocker with a minor tapping sound on the drivers side of the engine, however I could not tell if it was just a lifter not yet fully oiled or if I missed alittle on a valve adjustment.
Discovered I have a small crack in the valve cover bottom on the passenger side which is leaking now that they are cleaned up. I will have to remove, switch the bottom to the top and reset the gasket until I can pick up a new set of valve covers.
The engine seemed to be running even better than before, so I must have improved the valve adjustment on some of the cylinders.
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