Whats the big deal with LS7 lifters?
04-06-2013, 11:46 AM
#23
Edit:
Originally Posted by dirtbag
Man I've had to completely rebuild an LS1 4 times due to LS7 lifters failing. They are crap get a nice Morel or Lunati link bar setup and you will have peace of mind. I've had zero issues since making the switch to Morel 5206 link bars.
My LS7 lifters have been doing fine since I installed them, properly, back in 2006.
Last edited by Marc 85Z28; 04-06-2013 at 11:56 AM.
04-06-2013, 12:19 PM
#24
My point has nothing to do with mileage or LS1 vs. LS7 parts. My point is that a LOT of folks blindly ASSume that since they were LS7 they are "better" and in a lot of cases they are replacing perfectly serviceable parts with a false upgrade and in a bunch of cases the extra $120 they spent on lifters they pretend are an upgrade might even be causing them to cut corners somewhere else, the big push back against beehives contributes as a double spring setup is heavier and needs more pressure. Yes doubles offer much more safety in case of a break or something but people as several other folks here are saying are not putting together well thought out packages, they whole valvetrain is a system and it only takes one mismatched component to destroy a system.
04-06-2013, 12:25 PM
#25
Even the Gen.3-4 Vipers are having the same problems with these "LS7" lifters after switching from Eaton's .904 diameter lifters that were used in the Gen.1-2's. The Eaton's had really fast leakdown rates causing a host of issues. Created good vacuum but net lift would suffer in higher RPM's. Chrysler's cheap and readily available fix was to switch to a factory GM lifter. Hello blown up rollers...caused from more than one reason.
Remember, these are $120 parts trying to control cam and head packages we spend thousands on trying to reach full potential with a particular combination. Usually anything over stock ramp rates push OEM sorted/built lifters outside their working parameters. Will some work, yup. Will some fail, yup. A gamble far too many people make in my opinion.
04-06-2013, 10:10 PM
#27
Your arguement is that GM spent all that R&D redesigning the LS1 lifter for use and introduction in the LS7 engine for no reason at all?
Edit:
That's odd. I did a quick search on your name and LS7 lifters. I read a 8 month old thread about your "lifter" problem. Your pushrods were too long. You have no problems with the new lifters because your valvetrain is now setup properly, unlike before.
My LS7 lifters have been doing fine since I installed them, properly, back in 2006.
Edit:
That's odd. I did a quick search on your name and LS7 lifters. I read a 8 month old thread about your "lifter" problem. Your pushrods were too long. You have no problems with the new lifters because your valvetrain is now setup properly, unlike before.
My LS7 lifters have been doing fine since I installed them, properly, back in 2006.
2nd time - LS1 with bolts-on's, 224 cam, comp 918 springs. Flattened roller on lifter. Rebuilt block with stock rotating assembly. Professionally built motor.
3rd time - Same LS1 but 347ci, but this time with Wiseco pistons. Same comp 918 springs. Flattened roller lifter. Professionally built motor.
4th time - Same exact setup, with the addition of PRC .650 springs. Flattened roller on lifter. Done in my garage by myself.
See the trend? The thread from months ago was before the current motor was in the car. Valve train geometry was addressed and not the cause of the failure. The problem stemmed from starving the lifters of oil and metal fragments left over from the previous build in the oil galleys. I can't blame the lifters themselves for the failed engine in this instance, but the fallout from a previous lifter failure. I never got around to updating the thread. LS7 lifters are NOT designed for high lift aggressive lobes and high spring pressures. Yes, you can have an ideally setup valve train to reduce the chance of failure. An LS7 lifter failure IMO is not a matter of if, but a matter of when for some applications.
My $0.02 is spend the money now and get a nice set
.
04-07-2013, 08:30 PM
#28
04-07-2013, 08:32 PM
#29
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Can someone suggest a good link bar lifter?
Anyone have any experience with the Morel 5290?
Anyone have any experience with the Morel 5290?
Last edited by maverick18; 04-07-2013 at 08:58 PM.
04-07-2013, 09:40 PM
#30
There are only 3 reasons for LS7 lifter failure:
1. Excessive preload from using pushrods that are too long.
2. Launched lifters causing roller failure. Not enough preload or oiling issues.
3. Weak lifter trays.
The LS7 lifters ARE NOT THE culprit. If your LS7 lifter failed, stop looking at the lifters. Instead, look in the mirror.
Last edited by Marc 85Z28; 04-07-2013 at 09:45 PM.
04-07-2013, 10:01 PM
#31
GM has as much involvement in the design of the parts as the vendors. The vendors manufacture the parts to GM's specs.
No. Switching from the old LS1 style lifter to the newer LS7 absolutely requires a shorter pushrod. I don't care what you, GM, or Dodge says. I've measured. Many others have measured. The cup height is DIFFERENT. Screwing up geometry on a stock engine isn't nearly as big of a deal which is why you can swap them in stock engines without touching anything else. If you've got cam lobes that belong on a solid roller grind with big dual springs and turn a lot of RPM that geometry issue will show up in a hurry.
They work well, you just need to setup the valvetrain properly! I've got an MS4 with the aggressive LSK lobes on it with PRC's .650" dual spring. Since I installed my lifters 7 years and 25K miles has transpired, seeing 7000rpm+ every time I drive it. If it's just a matter of time, how much longer do I need to wait?
There are only 3 reasons for LS7 lifter failure:
1. Excessive preload from using pushrods that are too long.
2. Launched lifters causing roller failure. Not enough preload or oiling issues.
3. Weak lifter trays.
The LS7 lifters ARE NOT THE culprit. If your LS7 lifter failed, stop looking at the lifters. Instead, look in the mirror.
No. Switching from the old LS1 style lifter to the newer LS7 absolutely requires a shorter pushrod. I don't care what you, GM, or Dodge says. I've measured. Many others have measured. The cup height is DIFFERENT. Screwing up geometry on a stock engine isn't nearly as big of a deal which is why you can swap them in stock engines without touching anything else. If you've got cam lobes that belong on a solid roller grind with big dual springs and turn a lot of RPM that geometry issue will show up in a hurry.
They work well, you just need to setup the valvetrain properly! I've got an MS4 with the aggressive LSK lobes on it with PRC's .650" dual spring. Since I installed my lifters 7 years and 25K miles has transpired, seeing 7000rpm+ every time I drive it. If it's just a matter of time, how much longer do I need to wait?
There are only 3 reasons for LS7 lifter failure:
1. Excessive preload from using pushrods that are too long.
2. Launched lifters causing roller failure. Not enough preload or oiling issues.
3. Weak lifter trays.
The LS7 lifters ARE NOT THE culprit. If your LS7 lifter failed, stop looking at the lifters. Instead, look in the mirror.
How much longer are LS7 lifters than LS1's? I'm just installed them in my H/C swap that's in progress and need to know for PR length.
Also, would I be ok taking apart an LS7 lifter, making it solid, meauring for PR length and then reinstalling the lifter and using it for the build? I measured using my LS1's but if LS7's are different I have to measure using one of those.
04-07-2013, 10:20 PM
#32
They need a .050" shorter pushrod. Most of the time it doesn't matter, because they still like to operate around .080" preload.
And of course GM had input into the design. That's not how proposals are done. You send out an RFP and companies bid on the specifications and requirements contained in the RFP. The problem is, there are many ways to meet a design spec. The trade-off analysis that GM does when they award the contract means you get something that's designed for OEM reliability at the best possible bulk pricing. That doesn't mean it's designed for XE-R or LSK lobes or high-end dual valvesprings.
And of course GM had input into the design. That's not how proposals are done. You send out an RFP and companies bid on the specifications and requirements contained in the RFP. The problem is, there are many ways to meet a design spec. The trade-off analysis that GM does when they award the contract means you get something that's designed for OEM reliability at the best possible bulk pricing. That doesn't mean it's designed for XE-R or LSK lobes or high-end dual valvesprings.
04-07-2013, 10:21 PM
#33
GM has as much involvement in the design of the parts as the vendors. The vendors manufacture the parts to GM's specs.
No. Switching from the old LS1 style lifter to the newer LS7 absolutely requires a shorter pushrod. I don't care what you, GM, or Dodge says. I've measured. Many others have measured. The cup height is DIFFERENT. Screwing up geometry on a stock engine isn't nearly as big of a deal which is why you can swap them in stock engines without touching anything else. If you've got cam lobes that belong on a solid roller grind with big dual springs and turn a lot of RPM that geometry issue will show up in a hurry.
They work well, you just need to setup the valvetrain properly! I've got an MS4 with the aggressive LSK lobes on it with PRC's .650" dual spring. Since I installed my lifters 7 years and 25K miles has transpired, seeing 7000rpm+ every time I drive it. If it's just a matter of time, how much longer do I need to wait?
There are only 3 reasons for LS7 lifter failure:
1. Excessive preload from using pushrods that are too long.
2. Launched lifters causing roller failure. Not enough preload or oiling issues.
3. Weak lifter trays.
The LS7 lifters ARE NOT THE culprit. If your LS7 lifter failed, stop looking at the lifters. Instead, look in the mirror.
No. Switching from the old LS1 style lifter to the newer LS7 absolutely requires a shorter pushrod. I don't care what you, GM, or Dodge says. I've measured. Many others have measured. The cup height is DIFFERENT. Screwing up geometry on a stock engine isn't nearly as big of a deal which is why you can swap them in stock engines without touching anything else. If you've got cam lobes that belong on a solid roller grind with big dual springs and turn a lot of RPM that geometry issue will show up in a hurry.
They work well, you just need to setup the valvetrain properly! I've got an MS4 with the aggressive LSK lobes on it with PRC's .650" dual spring. Since I installed my lifters 7 years and 25K miles has transpired, seeing 7000rpm+ every time I drive it. If it's just a matter of time, how much longer do I need to wait?
There are only 3 reasons for LS7 lifter failure:
1. Excessive preload from using pushrods that are too long.
2. Launched lifters causing roller failure. Not enough preload or oiling issues.
3. Weak lifter trays.
The LS7 lifters ARE NOT THE culprit. If your LS7 lifter failed, stop looking at the lifters. Instead, look in the mirror.
<<<<< installed ls7 lifters with my cam swap 1 year ago and didn't use shorter pushrods...I drive the car all the time and ream on it on all the time so you are incorrect every engine is different you must measure for the correct length.
04-07-2013, 10:32 PM
#35
That would be interesting to note. I'm willing to bet super lightweight Ti valves help with whatever you put in an LS7.
Comp 850s, I believe, are designed like the LS1/LT1/96+ SBC lifters. Which is why a lot of shops push them as replacements if you have high miles on your stock lifters. It's much closer to the OEM LS1 lifter.
I think a lot of people defend the LS7 for no reason whatsoever. They defend them because they bought them. Pure and simple. I don't think anyone can say with a straight face that they are the best option for an aftermarket heads/cam setup.
Comp 850s, I believe, are designed like the LS1/LT1/96+ SBC lifters. Which is why a lot of shops push them as replacements if you have high miles on your stock lifters. It's much closer to the OEM LS1 lifter.
I think a lot of people defend the LS7 for no reason whatsoever. They defend them because they bought them. Pure and simple. I don't think anyone can say with a straight face that they are the best option for an aftermarket heads/cam setup.
04-07-2013, 10:41 PM
#36
Didn't read through this whole thread but if you do go with ls7 lifters they seem to be hit or miss on quality control from gm...ones I noticed had bad roller bearings...so I would check all of the ones you get before you put them in your motor know of 2 friends that had cam lobes take out from ls7 lifters...and when I checked a few brand new lifters you could feel a slight grind or rough spots when the rollers where moved by hand...it was not the case in all of the lifters...so I would at least check that as a FYI
04-07-2013, 11:53 PM
#38
I guess it would likely happen when reusing old trays that are worn where the lifter sits in and is no longer a tight fit, and then it will wiggle a bit and create friction and wear out the plastic over time and create a big enough clearance to spin..
04-08-2013, 06:48 AM
#39
That would be interesting to note. I'm willing to bet super lightweight Ti valves help with whatever you put in an LS7.
I think a lot of people defend the LS7 for no reason whatsoever. They defend them because they bought them. Pure and simple. I don't think anyone can say with a straight face that they are the best option for an aftermarket heads/cam setup.
I think a lot of people defend the LS7 for no reason whatsoever. They defend them because they bought them. Pure and simple. I don't think anyone can say with a straight face that they are the best option for an aftermarket heads/cam setup.
The titanium valves is a good point, and like I said earlier stock LS7s are beehive best as I can find. Beehives get the job done with less pressure and these days due to irresponsible setups and vendors having stuff made cheap offshore many folks are refusing to use beehives.
Steel valve with a double spring with half again the seat pressure, it is apples and oranges.
I am not saying beehives are better than doubles just saying they are different and I at least try to understand the benefits of each.
04-08-2013, 06:57 AM
#40
TECH Apprentice
so ... summing up.. ls7 lifters are a slightly better stock replacement over the ls1 lifters for a stock LS1 motor application.
correct me if i'm wrong just kind of the way i see it.
correct me if i'm wrong just kind of the way i see it.