• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

Installing LS7/Comp OE-R Lifters

TEK310

TEK310

New member
I will be installing these soon and want to do this correctly the first time.

I will be using comp reusable rocker bolts,

zzp 6.95"-5/16" pushrods (i just bought 7.05" stock length, but zzp says that will be too much preload for LS7 lifters.

i have cometic .052" head gaskets, which is .010" thinner

heads are milled .005"

stock rockers

stock valves

nic cam


do i set lifters on base circles or does it matter if they are open or closed with these engines? Then after that, what about preload. what torque + * of turn

Thanks in advance
 


soak them in oil a day or 2 before you throw them in. I think the bolts get torqued to 25 ft#
 
thats it?? dont have to set lifters on base circle of cam lobe then torque? what about when zzp website says 1/4-3/4 turn
 
I just torqued the bolts down then turned the motor over a few times and then rechecked the torque. You'll have to check the preload on them though.
 
It's a good idea to soak then like dsmuts said or sometimes they will be loud until the oil soaks them.


Just install them with the oil passage hole facing the same way so they wear evenly.
 
You can't adjust preloaded without adjustable rockers. Torque the rocker bolts to specs and make sure you have the correct pushrod length for your preload. There is literally nothing else you can do without adjustable rocker arms.
 


It is also worthless to soak the lifters in oil. That does nothing besides coat them. I always recommend the you pull the fuel pump fuse and crank the motor in spurts for about a minute total to get oil pressure built up.
 
GTPpower said:
You can't adjust preloaded without adjustable rockers. Torque the rocker bolts to specs and make sure you have the correct pushrod length for your preload. There is literally nothing else you can do without adjustable rocker arms.
Click to expand...

I always wondered this before I did my rockers. People were telling me about preload being important on aftermarket lifters and telling me about torque on the rocker bolts... and I would wonder, how do you adjust preload if you're torquing the rocker bolts to a specific number without any other variable on the rockers... it seems like either you torque them to 25, or torque them differently to adjust the preload, which didnt make sense to me.

So, I cranked them down to 25 and it was happy.

Thanks for clearing that up.
 
TEK310 said:
zzp 6.95"-5/16" pushrods (i just bought 7.05" stock length, but zzp says that will be too much preload for LS7 lifters.
Click to expand...

Can anyone verify this? I bought intense rods and the 6.95" wasn't even an option. I will be installing stock length rods on LS7 lifters this weekend. I would love to know.

Thank y'all...
 
slimguns said:
Can anyone verify this? I bought intense rods and the 6.95" wasn't even an option. I will be installing stock length rods on LS7 lifters this weekend. I would love to know.

Thank y'all...
Click to expand...

What can? And have you had the heads machined any?
 


You're supposed to check the length required with an adjustable pushrod (Pushrod length checker). Then order the correct length so you get your preload in the acceptable range, and have your rockers torqued to spec. You can also shim your rocker pestles if you need slightly less preload. It's not ideal, but it's cheaper than adjustable rockers or custom pushrods. Go with the closest pushrod, and shim if you have to.

Off topic: I ended up trashing my LS7 lifters somehow. They pumped up and locked at full height. Keeping my valves open. Car ran like a bag. Since the chance of 12 lifters all failing at once are slim to none, I presume I ****ed up using them with an XP cam and stock pushrods. Installing shorter pushrods did not help me any as they would pump up and measure differently. By the time the engine would cool down and I'd get the LIM/Blower off, they'd leak down to the "proper" height.

Again, very likely I ****ed up somehow, but still very frustrating as it was supposed to be a weekend job.
 
A local guy did XP cam with LS7 lifters and had to go with shorter pushrods. His preload was too much.
 


I've got an xp cam, ls7 lifters, stock pushrods, and about .010" milled from the heads. Probably about 30k miles on that setup.
 
Why not get the comp cam tool and measure first before you spend the money and get stuck with a set you can't use?
 
You must log in or register to reply here.
Back
Top