Floorman279

iTrader: (11)

so in the end both the dead soft touch method and the rocker turn yielded roughly the same results. i would have gotten that 7.333 number had i been looking for .070 preload from the start

01ssreda4

iTrader: (96)

The last 1/4 or 1/3 turn doesnt count as the bolt torques. So its total turns minus that last bit at 80 per turn and you should be on the money. With typical ls7 lifters they are so forgiving it doesnt really matter if you included the last bit of the turn or not, they will work regardless. I have no experience with Morels.

Floorman279

iTrader: (11)

i was gonna ask cause that little bit stretches at the end . so that actually should put me right around .060 so if i did everything right im all set

01ssreda4

iTrader: (96)

Edited, brain malfunctioned my apologies. So used to recalling that raggedy *** info Thunder Racing put out way back. Some old habits die hard.

Floorman279

iTrader: (11)

what do u mean by last 80 per turn

01ssreda4

iTrader: (96)

The 47 preload per turn info is the thread length of the rocker bolt. It is .047 per turn. The issue is because the rocker is a fulcrum, it multiplies this to .080 preload at the pushrod for every .047 full turn of the rocker bolt. I didn't believe that at first until I measured it myself with a dial indicator. One turn equals dropping the rocker center and bolt down 47, and dropping the pushrod side of the rocker down 80. So they don't drop equally. 1 turn equals 80.

Floorman279

iTrader: (11)

So now im confused. I read that elsewhere as well. How come u want 1.25 to 1.75 turns on ls7 lifters? Wouldnt that now be .1 to .14 preload then if one turn is .08? I no thats not true just dont get why

Floorman279

iTrader: (11)

I found a thread that explains it. Basically u find dead soft touch, then rotate the bolt with a ratchet until it just starts to torque the bolt. So that should be about 3/4 turn for .060 preload, then another half a turn of torquing give or take should be 22

01ssreda4

iTrader: (96)

Yep, thats it. The original post that stated 47 and 1.5 to 2 turns is incorrect, though it does typically work bc LS7 lifters are so forgiving. That post should have never been repeated.

Floorman279

iTrader: (11)

While ur here, im goona check for wipe pattern. You wantthe lifters to collapse right? Like no need for checker springs or lifters to be pumped? Just mark the valve and rotate the motor a few right?

Floorman279

iTrader: (11)

Also this question may be stupid. So on the cylinders that i have not torqued the rocker on to check my length, those lifters i cant depress. But on the cylinders i did torque, i can now easily compress the lifter and it springs back. If i were to torque on the cylinders that had the "springy" lifters, will they now show inaccurate rod length results?

Floorman279

iTrader: (11)

Didnt want it to turn into this,but im lost.

I tried a 7.4 rod. It took about 1.75 turns from dead soft touch til the ratchet took effort. Than it took about .3 turns to 22 lbs. i took one of the 7.325 rods i bought that measures 7.342 with a caliper, and that took about 1 1/8 turns until 22. So i took my checker, measured it to 7.3, and that took about .75 turns give or take a hair, and then that took also right about .3 turns with the torque wrench to get to 22. So do i really need a rod that short? These are supposed to be unmilled 799s. They have titanium valves and i have lash caps on them. The guy i bought them from said that with lash caps the valves are stock height. Also the wipe pattern with the 7.3 rods is pretty wide and goes from pretty much the end of the intake side to smack dab in the middle. I read somewhere wipe pattern on stock rockers will always be real wide.

01ssreda4

iTrader: (96)

If the valve is x high, and the rocker is on its fixed height pedestal the wipe pattern "should" always be acceptable and not need adjusting, since these heights are fixed, which is also why wipe pattern on these engines are rarely discussed.

As far as the spring-iness of the lifters. I think the ones you are saying are stuck are just tough. When my engines typically go together on the stand and i throw pushrods in I check that each lifter cup seems "normal". My experience is pushing on them by hand doesnt do much, youve gotta lean on them and put some shoulder on them to feel them spring back. This would be difficult to do if you were in a car.

As far as your measurements, I was normally getting 1.75 with a 7.425, which i think is very typical.....so that means most people are running .120ish preload and the lifters dont seem to mind. That same motor would likely run ok with 350, 375, 400, 425, and maybe even 450. The LS7s are just that forgiving I think.

Floorman279

iTrader: (11)

yea but i have morel 5315s so the accepted range is only .050 to .080 (absolute max)

01ssreda4

iTrader: (96)

So your measurement is much more critical.

gagliano7

Get the cam on the base circle for the cylinder your measuring. Adjust your adjustable pushrod until you have zero preload(lash) with rocker bolted down. Measure with calipers subtract .017( the difference from pushrod size to actual measurement) add desired preload and that is the pushrod length you want. I have the morels 5315 with a preload of .040 and my lifters are dead quiet.