Will LS7 lifters hold up?
I use to be a big fan of the LS7 lifters, now I recommend aftermarket when asked what I prefer to use.
The design of an aftermarket short-travel or tie bar style lifter is just flat out superior in every which way to that of a stock lifter.
You just have to ask yourself some questions:
What is my budget?
What are my intended usages for my car?
What RPM will I turn my engine to?
What type of open load and seat load do my springs have?
Is there a possibility my spring pressure is too great for a stock lifter to obtain full valve lift?
What lobes does my camshaft have?
What is the weight of my intake and exhaust valves?
What rockers am I using?
What push rod am I using?
There are so many things that go into choosing what valve train set-up is right for your application. This is where a shop or a cam guy that specifies you an entire valve train system and not just a cam that will make the most power with the most aggressive lobes is worth its weight in gold.
The design of an aftermarket short-travel or tie bar style lifter is just flat out superior in every which way to that of a stock lifter.
You just have to ask yourself some questions:
What is my budget?
What are my intended usages for my car?
What RPM will I turn my engine to?
What type of open load and seat load do my springs have?
Is there a possibility my spring pressure is too great for a stock lifter to obtain full valve lift?
What lobes does my camshaft have?
What is the weight of my intake and exhaust valves?
What rockers am I using?
What push rod am I using?
There are so many things that go into choosing what valve train set-up is right for your application. This is where a shop or a cam guy that specifies you an entire valve train system and not just a cam that will make the most power with the most aggressive lobes is worth its weight in gold.
Wow I didn't know they use Johnson short travel lifters in Top Fuel 
That is a pretty big sweeping statement, I would just state your personal experience, because just a few weeks ago you had morels and thought those were the cats meow...
I know of 4 people personally that have had ls7 lifters fail and take out a cam...and I also know of lots more making the same power and their ls7s are fine...keep the ramp rates soft and valves light, a good spring with not huge open rates is a good idea too...
That is a pretty big sweeping statement, I would just state your personal experience, because just a few weeks ago you had morels and thought those were the cats meow...
I know of 4 people personally that have had ls7 lifters fail and take out a cam...and I also know of lots more making the same power and their ls7s are fine...keep the ramp rates soft and valves light, a good spring with not huge open rates is a good idea too...
And yes, I still stand behind my assessment of Morel. On the whole, they are great lifters. After doing more research, I wanted to swap over to a short-travel lifter. The Johnson's are more cost effective than the Morel short-travel and are built to withstand similar spring rates and RPMs.
Also, the entire system has to be matched well. With mild enough lobes, light spring pressure, and stiff pushrods, LS7 lifters would actually work. But I'd rather get better tolerances, better materials, and a link-bar setup. The Street Morels provide that at a better price point than the others. But if you want to step up to much more expensive lifters, I'd like to get additional features like the short-travel and axle oiling with the Johnsons.
Guys, I know the LS7 might not be the end all be all lifter out there, but just about every C6Z H/C swap uses LS7 lifters as the replacement. Again, I'm not stating that there aren't better products out there, there is just a whole bunch of folks running them w/o an issue and spinning their motors too and past 7k.
Last edited by 427zm; Aug 6, 2013 at 03:28 PM.
Love me some stiff push rods...mmm...beefy.
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Staging Lane
Joined: May 2012
Posts: 85
Likes: 0
From: Tri-Cities, TN
I didn't know any .842" lifters in the LS1 are in Top Fuel... For these cars, the Johnsons will handle the spring pressures you normally see.
And yes, I still stand behind my assessment of Morel. On the whole, they are great lifters. After doing more research, I wanted to swap over to a short-travel lifter. The Johnson's are more cost effective than the Morel short-travel and are built to withstand similar spring rates and RPMs.
Also, the entire system has to be matched well. With mild enough lobes, light spring pressure, and stiff pushrods, LS7 lifters would actually work. But I'd rather get better tolerances, better materials, and a link-bar setup. The Street Morels provide that at a better price point than the others. But if you want to step up to much more expensive lifters, I'd like to get additional features like the short-travel and axle oiling with the Johnsons.
And yes, I still stand behind my assessment of Morel. On the whole, they are great lifters. After doing more research, I wanted to swap over to a short-travel lifter. The Johnson's are more cost effective than the Morel short-travel and are built to withstand similar spring rates and RPMs.
Also, the entire system has to be matched well. With mild enough lobes, light spring pressure, and stiff pushrods, LS7 lifters would actually work. But I'd rather get better tolerances, better materials, and a link-bar setup. The Street Morels provide that at a better price point than the others. But if you want to step up to much more expensive lifters, I'd like to get additional features like the short-travel and axle oiling with the Johnsons.
On The Tree
Joined: May 2011
Posts: 157
Likes: 2
.750 wheel lifter > .700 wheel lifter... End of story. Street series morel's are on a .700 wheel, but the 5206 morels use a.750 wheel. That is what makes a morel different than a stock gm lifter or other popular brands that are more affordable. A larger wheel can simply take more load.
The main issue with running a .750" roller in an .842" diameter lifter is the forked end of the body. There are plenty of pictures floating around with the "fork" broke off. This happens due to embrittlement caused from from cam walk, violent lobes, and high spring pressures. Once the forks start deflecting it changes the centerline of the roller and also puts strain on the staked roller axle, causing it to walk or start spinning. We all know what happens when that occurs...chews up a cam or you need to sleeve some lifter bores. With that style body you cannot stake the axle as hard as you can a fully shrouded .700" roller. Obviously these are the few and far between failures. Both designs have been around a long time and work with many combinations...
Still, the main cause for bearing failures is the lack of oil to the bearing during low oil pressure conditions (idling). Unless your dealing with poorly sorted needle bearings stuffed inside a sub-par housing...then all bets are off LOL!
