Lifter preload check with L92 / Yella Terra's
09-01-2008, 01:40 PM
#1
Lifter preload check with L92 / Yella Terra's I'm attempting to check lifter preload. Stock LS2 block, L92 heads milled 0.030", LS7 lifters, 7.400" pushrods, and Yella Terra rockers. I tried the scribe method, but do not have anything sharp enough to mark the pushrod or a marker or anything with a sharp enough point to do it. Even if I did, I'm not sure I have an easy way to mark it the same place each time.
I do have a Comp Cams adjustable pushrod, but the problem with using it is that I cannot adjust it while installed because the adjustable long portion of the rod is too far down in the head to hold it while I adjust the short end. So, I've tried to just remove / install the rocker adjusting it a bit at a time, and then use a feeler gage to measure the difference between the 0 lash and my 7.400's.
I did also try a redneck way of doing it...by using a steel ruler to lay across the machined surface of the head, then used the depth rod of my vernier caliper to measure before and after at the oiling hole direcly above the pushrod.
I also don't know if I'm doing it right with the Yella Terra's....since they have two bolts, I'm relaxing the torque on one bolt while I check the preload on the other. If I don't the torque of just one side will not allow the lifter to spring back.
I did just buy a dial indicator, but Sears has the audacity to sell it without any mounting hardware at all...so I'll have to rig it if I'm to make that work.
How did you check yours?
Gerry
I do have a Comp Cams adjustable pushrod, but the problem with using it is that I cannot adjust it while installed because the adjustable long portion of the rod is too far down in the head to hold it while I adjust the short end. So, I've tried to just remove / install the rocker adjusting it a bit at a time, and then use a feeler gage to measure the difference between the 0 lash and my 7.400's.
I did also try a redneck way of doing it...by using a steel ruler to lay across the machined surface of the head, then used the depth rod of my vernier caliper to measure before and after at the oiling hole direcly above the pushrod.
I also don't know if I'm doing it right with the Yella Terra's....since they have two bolts, I'm relaxing the torque on one bolt while I check the preload on the other. If I don't the torque of just one side will not allow the lifter to spring back.
I did just buy a dial indicator, but Sears has the audacity to sell it without any mounting hardware at all...so I'll have to rig it if I'm to make that work.
How did you check yours?
Gerry
09-01-2008, 06:32 PM
#2
Staging Lane
iTrader: (3)
Join Date: Aug 2008
Location: Texas
Posts: 54
Likes: 0
Received 0 Likes
on
0 Posts
I tighten down the YT hand tight. I just turn the adj push rod checker in until you can move the rockers easily. Take the YT off, adj the push rod checker and reinstall YT. Just keep track of how many 1/4 turns. Go out until you take up all the play and then back down again to double check. I also lay the adj push rod against a stop and measure the length, so If I get screwed up on where I am, I can easily check with out having to screw it all the way in and count the turns again.
09-01-2008, 07:16 PM
#3
Banned
iTrader: (5)
Join Date: Apr 2003
Location: Chicago
Posts: 1,890
Likes: 0
Received 0 Likes
on
0 Posts
If you think you need a 7.400 pushrod, measure out the adjustable pushrod to 7.350" install it and you should have near 0 preload 0 lash.
must be on base circle of the cam.
hint, we have typically needed 7.350" pushrods with L92 heads, so perhaps you will want to measure with a 7.300" adjusted length see what happens, then try 7.325".
must be on base circle of the cam.
hint, we have typically needed 7.350" pushrods with L92 heads, so perhaps you will want to measure with a 7.300" adjusted length see what happens, then try 7.325".
09-01-2008, 08:11 PM
#4
If you think you need a 7.400 pushrod, measure out the adjustable pushrod to 7.350" install it and you should have near 0 preload 0 lash.
must be on base circle of the cam.
hint, we have typically needed 7.350" pushrods with L92 heads, so perhaps you will want to measure with a 7.300" adjusted length see what happens, then try 7.325".
must be on base circle of the cam.
hint, we have typically needed 7.350" pushrods with L92 heads, so perhaps you will want to measure with a 7.300" adjusted length see what happens, then try 7.325".
So....is .050" preload good?
Gerry
