push rods length and adjustment
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push rods length and adjustment
just did a head replacement on the my 90 bronco that has had an older 302 put in it and not shure wher to go now the heads are closed chamber ho heads and the heads removed are standard 302 heads my question is do i adjust my rockers or just crank them down like my others when i put the pushrods in and cranked them down it seemed to pushed my valve down and i dont think they are seating all the way started it last night barely ran question is can i adjust the rockers or are they meant to cranked down? the stud height is the same and everything changed over fine and just hoping that i did right by doing this swap thanks in advance
Last edited by chevygoneford; Feb 4, 2007 at 08:52 AM.
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Joined: May 2003
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From: south louisiana
If these had pedestal rockers like the 90 heads, just torque the bolts down to 25 ft/lbs. If they're studs, look at the studs. Ford switched from an adjustable stud to a positive stop type in 68 or 69. The positive stop stud has a bigger shank where the theads stop. The fulcrum will bottom against the shank on these, limiting the nut travel. These also torque down to a set amount, I just don't recall what that is, something like 30-45 ft lbs should be right.
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adjustment
am i supposed to adjust these like a bowtie moter or just crank them down to a torque specified when i crank them down i can see the valves being pushed down and opening and if i do have to adjust will they stay adjusted i have 6 7/8 push rods are there shorter rods that i can buy thanks in advance its negative 5 degrees today and i dont care as long as i drive it today
Hotshot
Joined: May 2003
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From: south louisiana
If they're positive stop studs or pedstal rockers, just torque em down. Some valves will be opened as this is done. Or do them, one at a time going thru the firng order, either way works. Early Ford firing order is the same as a Chevy, later 351W order is the same as the newer LS1's. Cylinders are numbered different is why the FO seems different. Number the cylinders like a Chevy, the FO is the same.
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got it
they were right got it running but the plugs were wrong too short had to get plugs for a crown vic ran alot better lot more power thanks for all the help now just have to fine tune it thanks again
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From: Williamson, NY
With pedestal or positive-stop type rockers and a head swap you need to check that your push rods are the proper length to achieve the proper valve geometry. To check for proper push rod length, you need to have the lifter on the base circle of the cam and then loosen the rocker nut/bolt until the push rod is loose. Then tighten the nut/bolt until the push rod no longer moves up and down. Then count how many turns it takes til the nut/bolt bottoms out. If your push rods are the proper length it should only take between 1/4 to 1/2 turn to bottom out the nut/bolt. If it takes less or more than the 1/4 to 1/2 turn you will need to order new push rods of the proper length. To get the correct push rod length you will need to get a push rod length checker. Jegs and Summit have them if you need one. Good luck.
