I called Lunati today to double check preload for the lifters I purchased and the tech told me 0.050". Here's how the conversation went.

Me: Hi, I just wanted to know how much preload I should be using with my LS1 lunati lifters?
Tech: Is it an aluminum block?
Me: Yes
Tech: What size cam?
Me: 223/234 .636"/.599"
Tech: What's the stock preload?
Me: 0.050-.100 I believe
Tech: Set them at 0.050 then

I've heard a few guys say that these are the same as Morel's which run between 0.020-0.030". 1st question is is our stock preload 0.050-0.100? I'm pretty sure that's what I've read. Second is, does the size of the cam have any affect on what your preload should be? Why would he ask me what size cam I had if it didn't matter?
Thanks for your input guys, I don't want to wreck something and have to take this thing apart again.

 

I have run iron block motors around 1/4-1/3 turn preload before the bolt is tight(not sure what that actually measures out to) and alluminum blocks closer to 1/2 turn and built good running combos (420rwhp 346's w/a-4, over 500rwhp 370 w/a-4 trans, etc.) I have heard of dyno comparrisons where the lash has been altered from zero lash to a full turn and not a single hp change. Stock is around a full turn I think. I personally like them with less preload than most because I think the motors are more responsive. You need some preload to avoid noise and valvetrain wear. Cam size has no effect on adjustments when it comes to hydraulic lifters. I hope this helps, I know cam companies have their own opinions.

 

The Morels and Lunatis are the same. Set it to .030" for it to run optimally. And stock preload is around .100".

 

how u will u measure this preload?im getting the hardland non adjustable or the yellow terra non adjustable so does this preload gos for me too

 

Thanks for the responses. Anyone else running lunati's out there?

 

I am running Morels, which are the same as the Lunati's, at least one of the Lunati part numbers. I am running mine at 0.040". I spoke to Morel and they told me to use a little more preload than the 0.030, which they thought was too low for an aluminum motor. They recommened 0.040 - 0.060". Others have recommended 0.030 to 0.050 so I set them at 0.040. I am running Crane rockers, so getting the preload was easy.

 

My Morels are set to .040 like vettenuts, stock rebuilt Harland Sharp rockers, 7.300 pushrod.

 

Thanks a lot guys. Guess I'll shoot for 0.040-0.050 then.