Engine Help With Pushrod Length And Stock Rockers

jraap82

Active User
Aug 29, 2016
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I'm having a hard time finding any information on this for other than roller rockers. I have an 89 GT me and my son are rebuilding and don't have the funds for new roller rockers at the moment. This is also my first engine rebuild so breaking it down dummy style will definitely not offend me (I'd probably prefer it, lol). The engine has been bored 30 over, stock ZE cam and 3-bar GT40 heads.

I'm looking for any info on how to measure for correct pushrod length with the stock no-adjust bolt-fulcrum type rocker arms.

Also, do I measure piston to valve clearance before this or after getting correct length pushrods? I'm assuming after but want to be sure.

Any info will be much appreciated, thank you!
 
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if you are running a stock head, stock rocker arms, stock cam and havent milled the heads or deck extensively, there is no need to get custom pushrods or measure PTV clearance,. Stock pushrod length is 6.272 inches long. If you are still interested in measuring for correct push rod length

 
if you are running a stock head, stock rocker arms, stock cam and havent milled the heads or deck extensively, there is no need to get custom pushrods or measure PTV clearance,. Stock pushrod length is 6.272 inches long. If you are still interested in measuring for correct push rod length



Thanks for the response mikestang63, I appreciate it. I bought the heads used so I'm not sure if they've been milled at all or not. I've watched that LMR video a hundred times probably too, haha! I didn't know if the process was the same or not being that I'm not using the roller rockers. I read somewhere today about non adjustable rockers that I should put them on and hand tighten the bolt to zero lash then torque to 20 ft/lbs and as long as it torques between 1/4 and 1 full turn of the wrench then they're good. Do you know if this is correct? Also, should I use one of the solid lifters to do this or just fill the lifter with oil first? Sorry about all the questions, just want to make sure I do this correct. Again, thank you for the information!
 
what makes you think you do not have roller rockers? Unless you have a pre 85 block,. you have them. Stock HO motors have roller rockers. . look at the lifters and they should have a roller on teh bottom. Normal hydraulic lifters are flat on the bottom with no roller. What you are referring to are pedestal mount roller rockers vs. stud mount. Stock ( pedestal) roller rockers are non adjustable and you tighten them down to zero lash on a pumped up roller lifter, and then look to get around 18-20 ft lb in 1/2 a turn. If you cannot get the torque within turning the torque wrench that amount you need to use shims under the rocker pedestal. Ford sells them and you don't want to go more than .060 IMO. if you can't move the torque wrench at the 1/2 turn before getting the proper amount of torque you need a custom pushrod length. I highly doubt you will need longer pushrods unless they milled the hell out of the heads.

Here is a good video on how to adjust your factory roller rockers. Just make sure the cam is on the base (heel of the cam lobe) when you set the lash and then rotate the crank 90 degrees and then adjust the next set of valves in the timing order.

 
what makes you think you do not have roller rockers? Unless you have a pre 85 block,. you have them. Stock HO motors have roller rockers. . look at the lifters and they should have a roller on teh bottom. Normal hydraulic lifters are flat on the bottom with no roller. What you are referring to are pedestal mount roller rockers vs. stud mount. Stock ( pedestal) roller rockers are non adjustable and you tighten them down to zero lash on a pumped up roller lifter, and then look to get around 18-20 ft lb in 1/2 a turn. If you cannot get the torque within turning the torque wrench that amount you need to use shims under the rocker pedestal. Ford sells them and you don't want to go more than .060 IMO. if you can't move the torque wrench at the 1/2 turn before getting the proper amount of torque you need a custom pushrod length. I highly doubt you will need longer pushrods unless they milled the hell out of the heads.

Here is a good video on how to adjust your factory roller rockers. Just make sure the cam is on the base (heel of the cam lobe) when you set the lash and then rotate the crank 90 degrees and then adjust the next set of valves in the timing order.



Sorry about the confusion on the terminology of this, learning as I go. Thank you for the patience and help on this though, it is MUCH appreciated!! I will be doing this within the next couple days and feel more confident now and am super stoked to get this engine back together and running again.

Respectfully,
Joe