73 Q Code Rocker Arm Reinstallation?

7173Mustangs.com

Help Support 7173Mustangs.com:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

7173Vert

Well-known member
Joined
Sep 14, 2018
Messages
906
Reaction score
300
Location
Ontario
My Car
1971 Convertible, 1973 Hardtop
I changed out my valve seals. Before I retorque the rockers (positive stop, non adjustable), I started thinking about the procedure to do it properly. I keep thinking about the pre load on the lifters and making sure that I tighten them down in proper sequence. It has been 20+ years since I last did this. I do have the factory manuals to go by as well, but wanted an additional opinion from those that have done this with the heads still on the car. I believe the torque setting is 20 ft/lbs. Can someone that has experience confirm the procedure for me, please and thanks. 

 
Typically when I set lash I set the intake when the exhaust valve begins to open and set the exhaust when the intake is just after max lift. This ensures the lifters are on the base circle when set. I do 1 cylinder at a time. To me it's simpler than finding TDC. 




 
5 hours ago, droptop73 said:

Typically when I set lash I set the intake when the exhaust valve begins to open and set the exhaust when the intake is just after max lift. This ensures the lifters are on the base circle when set. I do 1 cylinder at a time. To me it's simpler than finding TDC. 


Hmmm. Maybe I wasn't clear. They are hydraulic lifters (original), positive stop pedestals. Sorry about that.

 
No, you were clear no need to apologize.

If you want to tighten them in sequence the method works for solid or hydraulic lifters. With fixed hydraulics tighten the bolt to the service spec. With adjustable hydraulics tighten until you feel the slop go out of the pushrod and then tighten another 1/2 turn. I included the video as it illustrates the lash sequence that will work for any engine. With the fixed pedestals it's a bunch of extra work to go through the sequence in my opinion. 

 
No, you were clear no need to apologize.

If you want to tighten them in sequence the method works for solid or hydraulic lifters. With fixed hydraulics tighten the bolt to the service spec. With adjustable hydraulics tighten until you feel the slop go out of the pushrod and then tighten another 1/2 turn. I included the video as it illustrates the lash sequence that will work for any engine. With the fixed pedestals it's a bunch of extra work to go through the sequence in my opinion. 
Fair enough. That’s what I figured. The factory manual also goes through the sequence similar to your comments. I was aware of the adjustable lifter requirements as I have previously

Hydraulic lifters? Put piston at TDC and torque down both rockers for that cylinder. Repeat 7 more times 
done the procedure exactly as you describe. Better safe then sorry....

 
7173vert, once I get to zero lash (with positive stop) I will put my ratchet handle to a  clock position and then count how far it goes before the bolt starts reaching torque, (that will tell you how much preload you actually have. 

If over 1 full turn, will usually add one of the little Crane rocker shims, thinner of the two that usually come in a standard pack.

Boilermaster

 
Back
Top