Hey again, Just was installing my pushrods today, they are going into my 68 350 motor, i put a set of 6x heads off of a later 70's 400, and was installing the pushrods, now i have done this before, not on a real motor(pontiac) though, but when i was tightening down the rocker arm, it seems there is still a fair amount of play in the rocker arm, can anyone send me the procedure on how to properly do this for a pontiac motor? I searched previous posts and have read up a bit about torquing them down to 20ft lbs, and i kept on tightening until i can't anymore and there is still play, would it be safe to say im not using the proper length pushrods?? they are the stock pushrods, and stock rocker arms, but still out of tightening one side of the motor, only two of them could even be tightened down to not chatter. any suggestions or the proper method to installing this? thanks
Ps. you can email me the details or any info to firebird_68@sympatico.ca if it is a long document as i saw in very old posts that people had the method on email or anything like that.. Thanks
Hey thanks for the site. So i went ahead and set the pushrods tonight, it is the same size rods, same everything that ran fine before, so i first adjusted the 4 intake and 4 exhaust as said in the instructions with cylinder #1 at TDC like it said, and then turned the crank a full 360 degrees and did the other 4 intake and other 4 exhaust like stated, but when i went back and checked the first 4 of each that i had adjusted, 2 of the 8 valves/pushrods that were first adjusted, the rockers have a fair amount of play in them, enough to make me wonder, does this sound correct? Should i be worried? thanks Nick
A small amount of play, like half a turn, is normal. Just keep going over it until you don't have the slop. If the play is like a turn or more you may have been 360 off when you started. If this is the case start over. Whenever I set up the rockers I find slop the second and even third time around. Jim
I use a slightly different method. I hook up a remote starter button, and set the valves one at a time, starting at the front of the head and working back. For an exhaust, I crank the engine until the paired intake valve has opened and is almost closed again. This makes sure that the exhaust lifter is on the base circle. For an intake, I crank the engine until the exhaust valve starts to open, for the same reason. Don't get mixed up on which is exhaust and which is intake. I make the adjustment, put a tick mark on the rocker with a felt pen, and move on to the next valve. When I'm done on that head, I wipe off the tick marks and do the other head. No firing order or which cylinders get adjusted in what position to remember, so less likely to make mistakes IMHO. Hydraulic lifters can bleed down when the valve is held open for a short time, which is possibly why you're getting play after adjusting. Could also be that the lifter wasn't quite on the base circle during adjustment, which is why I use this method to make sure it is. Gets it done right the first time.
I have tried doing this method as on that site, and still having the same problem, after i adjust the 8 valves when the #1 piston is at TDC, i go to the #6 pinston at TDC, and about 3 of the first 8 that were adjusted, the rocker arms are so loose that i can take them right off of the pushrod, and when i spin the motor over back to the piston being at #1 TDC, they are all tight again and i can spin the pushrod exactly how tight i could before, and the rockers all get tight agian, while the 3 of the 8 pushrods that were adjust when the piston was at #6 TDC, 3 of the rockers are loose enough now to take right off of the pushrod... if that sounds too confusing let me know, i am really lost here, are they supposted to be this loose? i have set them now about 3 or 4 times, and every time it is the same issue... what could it be? or are the rockers supposed to be that loose?
Try TOHCan's method instead, or go one cylinder at a time. I just went through all this on a new 400. I do it by the firing order, starting at #1 and pushing the timing mark past the 0 by about 15 -20 degrees. Then, note the position of the four bolts on the crank pulley. Go 1/4 turn of the crank and do #8, then 1/4 turn and do #4, etc.
#1 is the driver's side front cylinder. The timing mark will be at TDC on either #1 or #6. Make sure you're starting with the right one. With the timing mark just past the TDC mark, both valves will be fully closed on #1. If both valves are fully closed on #6, you're one turn off.
