sc6speed

I was curious if anybody has done or knows if it'll be safe to run the Morel 5315 drop in lifters at .070 preload? I ask because I was having some valvetrain noise after heads/cam. I found I had too short of a pushrod in the motor. I checked for length using the comp cams checker and eo/ic method. I got 13.25 turns on some valves, 13.5 on some, and right under 14 on some for zero lash. I ordered a 7.525 pushrod. This will put the preload on some of the valves at almost .070.

Cstraub

iTrader: (1)

Total travel on the lifter is .140". Your fine at .070" We end up with many BBC at that amount of preload.

slogo

So Reading this, can I assume the ideal preload will be half of the travel of the
plunger inside lifter, for all lifters?

gagliano7

I was told on an iron block aluminum heads the ideal preload is .045. I am right around there and my motor is dead quiet.

Cstraub

iTrader: (1)

Each engine is different. There for preload needs to be looked as a range. Your going to fall from .040 to .080" depending on application. Since Aluminum has a higher expansion rate then iron, an engine with all aluminum block and heads will grow more, DECREASING the preload. These engines will need more preload then an engine that has an iron block and aluminum heads.

sc6speed

Appreciate it yall. I've had one or two (one being a reputable distributor/builder) tell me that .080 would be the safe max. Everyone else seems to say that roughly .035-.065 is the safe range. I've got 3 intake valves that will be running a slightly shorter pushrod than the rest, in order to fall in that range. Apparently this is pretty common. Thanks for the input everyone!