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Yeah I have no horse in the LS7 lifter roundup, just following the thread. Agree springs are a wear item and do need to be checked on modified motors. As tedious as it is to pull a few I did at 5k, 10k, 15k...and before the 20k mi I decided to swap the springs more because the upper RPMs the motor just started to slightly feel like it was starting to nose over vs still pull to 6200 where I shift at the track. I bought the Lunatti spring kit from Lloyd to replace the 918's. BTW Lloyd says he will not sell or install 918's period anymore.
Well as I was pulling the retainer off one spring a coil came with it...but fortunately the retainer was securing the spring so no damage for me. It certainly was alarming and even following 5k intervals in checking a few springs over the years this spring broke. IDK when it broke as I checked different springs each time. Engine ran fine at the time I did the spring swap
Does this mean people with LS7 lifters need to pull them and check them out. IMHO only of "valve train tick" seems persistent even after careful re-lash. Otherwise just run it or do the Blackstone oil test thing to see if "something" is in oil.
I just did this for the first time not because I had any symptoms or issues but just curious how my test results would be For $28 it is a simple deal. My results were excellent on my 40+k mi 383
Yeah seen that before. Far too common but even a nick on the side of a coil during shipping, handling, install can be enough to cause a spring failure. Sure there are springs that have neen dropped on the floor, kicked all around, and still held well, but some do not and any scars only increase risk of failure. I had great success with stock GM beehives, as well as PAC1518 which were another one that had some bad batches but not in my case they worked well. I've also run PSi1511ML and worked out well, trying them in my own 6.2 now as well. Stock LS7 lifters from Summit, new trays as well.
I've had the same set of LS7 lifters in my LT1 since 2008, I have zero complaints. I can't help to wonder that some of the people that have had LS7 lifter issues over the years unintentionally bought rip-off LS7 lifters. There's unfortunately a lot of fake LS7 lifters out there, especially on ebay.
My impression has been that LS7 lifters have been the most common replacement in LT1s for over a decade now, so that's probably 10's of thousands of LTx engines running around with them.
Given such common usage, there are bound to be a few failures whether from user error (most likely) or other defects.
The LS7 lifter has made its way into every engine in the LS family from the factory. The lifter has its limitations, but a properly set up valvetrain will typically warrant zero issues so long as the lifter isn't being used on a cam with aggressive ramp rates, .650"+ lift, and ungodly spring pressures. Just don't expect to throw the lifters in without checking your lash and sweep patterns.
I'm currently running LS2 lifters in a Vortec 350.
I think it was mentioned within this thread that LS7 valves are sodium filled, thus lighter, than the typical solid, heavier, LT1 valve
So does this make LS7 lifters used with solid valves with cams that have high lift and aggressive lobes hitting 6500+ RPM more prone to...."fatigue" faster or flat out collapse under those conditions...IDK. But that scenario may be a contributing, if not the, factor in reported failures of the LS7 lifter.
I would think in mild builds that don't see 6500+ rpm use they may be just fine but more prone in more aggressive builds
Clearly many run them without issues but at the same time there have been several threads stating issues. As in anything "operator error" can be part of the equation but maybe the fact the LS7 motor has lighter valves the LS7 lifter used with solid heavier valves may not perform as designed under those use conditions. Similar to why LT4 springs were never good with LT1 and higher lift than stock cams because of the heavier solid valves in LT1's
Not every LS engine came with sodium valves, but a majority of the engines came with LS7 lifters from the factory. So, I highly doubt that valve weight plays any role with these lifters' longevity. I'd be interested to see if those reporting failures had purchased the Delco lifters or the cheaper Delphi lifters. I'd also be interested to see how they set up the valvetrain with the LS7s.
Not every LS engine came with sodium valves, but a majority of the engines came with LS7 lifters from the factory. .
The Op's ? is about "LS7" lifters. IDK if that same lifter cam in prior versions of the LS motor....but the "LS7" motor has sodium filled valves which are lighter than solid valves
Yeah we don't know if lifters referred to in several threads as being "LS7" are AC Delco, Delphi or off shore clones (crap)...let alone for the most part how valve lash or geometry or what springs were involved and installed at what "height"...so yeah there are several unanswered ?'s in many of the posts about LS7 lifters....but there certainly are more "problem" LS7 lifter threads than other lifters IMHO
LS7 lifter is the lifter used across the board in LS engines from 07+ its nothing special its merely AT THAT TIME the latest revision to a lifter GM had and was deemed better because of the deeper column to the lifter body and another small change or two I cant recall. Ticking lifters has been an issue with LS engines from day one and is still to this day. Problems being more common place today line right up with more people wrenching together their own engines and 9/10 the mechanic is the problem not the parts used. I've had many LS vehicles now, and worked on more than I can think of and never had a single issue with an LS7 lifter in OEM installs or my own.
Its always wise to consider who worked on the engine before blaming the parts. Even the worlds greatest engine builders, still make mistakes so any shade tree guy that never made an error in wrenching is clearly needed at NASA
...so yeah there are several unanswered ?'s in many of the posts about LS7 lifters....but there certainly are more "problem" LS7 lifter threads than other lifters IMHO
Yes, because there are orders of magnitudes more LS7 lifter users than there are Morel or whomever else that makes lifters.
The Op's ? is about "LS7" lifters. IDK if that same lifter cam in prior versions of the LS motor....but the "LS7" motor has sodium filled valves which are lighter than solid valves
GM put the LS7 lifter in every LS engine starting around 2007/2008. That means that everything, from the LS9 to the 4.8, received LS7 lifters. At that point in time, even if you went to a dealership and wanted a replacement lifter for your 1998 LS1, you received an LS7 lifter.
Originally Posted by ******
Yeah we don't know if lifters referred to in several threads as being "LS7" are AC Delco, Delphi or off shore clones (crap)...let alone for the most part how valve lash or geometry or what springs were involved and installed at what "height"...so yeah there are several unanswered ?'s in many of the posts about LS7 lifters....but there certainly are more "problem" LS7 lifter threads than other lifters IMHO
That is a whole lot of missing information one should deem pertinent to include in any judgment of a part's quality.
Not every LS engine came with sodium valves, but a majority of the engines came with LS7 lifters from the factory. So, I highly doubt that valve weight plays any role with these lifters' longevity. I'd be interested to see if those reporting failures had purchased the Delco lifters or the cheaper Delphi lifters. I'd also be interested to see how they set up the valvetrain with the LS7s.
Most of those LS engines were designed to only rev to about 58-6500rpm with very soft loft lobes and light springs. The ones that rev out to 6800- 7k have light valves for a reason....so yes valve weight and weight over the valve stem is very critical for high rpm. Again if your are building a heads/cam car that is going to rev to 68-7200rpm and use heavier springs with a more aggressive lobe, a lifter with less travel would be a wise investment.
Most of those LS engines were designed to only rev to about 58-6500rpm with very soft loft lobes and light springs. The ones that rev out to 6800- 7k have light valves for a reason....so yes valve weight and weight over the valve stem is very critical for high rpm. Again if your are building a heads/cam car that is going to rev to 68-7200rpm and use heavier springs with a more aggressive lobe, a lifter with less travel would be a wise investment.
Except the LS7 and LS6 both had redlines of what? 6800-7k? I would only go aftermarket lifter if shifting above 7k alot.
Except the LS7 and LS6 both had redlines of what? 6800-7k? I would only go aftermarket lifter if shifting above 7k alot.
Yea and they both had light weight valves but the LS6 didn't have LS7 lifters anyway...which supports my previous post. RPM is not the only thing to spec lifter selection on. You need to consider cam lobe intensity and Valve spring pressures. LS7 lifters don't particularly like springs with high open/closed pressure or cam shafts with high intensity lobes combined with high rpm.
Yea and they both had light weight valves but the LS6 didn't have LS7 lifters anyway...which supports my previous post. RPM is not the only thing to spec lifter selection on. You need to consider cam lobe intensity and Valve spring pressures. LS7 lifters don't particularly like springs with high open/closed pressure or cam shafts with high intensity lobes combined with high rpm.
Yes, but an LS6 lifter is different from an LS7 lifter how? I agree about heavy spring pressures and radical cams, I'm just stating that 6300 is not the limit of an LS7 lifter by a long shot.
The ls7 lifters are garbage in a race engine. Race engine = over 6500 rpm, high pressure springs, hardened steel valve train components. These things are just part of keeping the valve exactly where you want it. If the valves are not where they should be at your max rpm, miss shifts included, your engine and all the money and work go poof! Hydraulic lifters hold oil. That oil is what is poisoning your valves. With over .100 pre load of oil the oil has to be just right for the timing for you events. When the oil is hot and moving extremely fast It collects air bubbles. These bubbles collect inside the lifter to the point of collapse. That can be a catastrophic event with so much travel. That's why GM wont use an ls7 lifter in a ls7 engine. The original ls1 lifters had less travel than the replacement ls7 lifter. Still want them in your engine?
Last edited by handyandy496; 09-07-2018 at 12:06 PM.
Yes, but an LS6 lifter is different from an LS7 lifter how? I agree about heavy spring pressures and radical cams, I'm just stating that 6300 is not the limit of an LS7 lifter by a long shot.
The plunger cup is different...The bodies are different...The part number is different. I didn't say 6300 was the limit...LS7 lifters can be spun higher if the cam and valvetrain are setup correctly with the correct parts which has been proven with LS7 and LS3 engine because they run light weight valves, light beehive springs, and soft lobe cam with lift under .600. Most want to run a cam and valvetrain setup that is outside of the LS7 lifters tolerances is my point...some get away with it some don't. I wouldn't run a LS7 lifter on a LT1 engine with stock valves, heavy double springs, heavy roller rockers, and a fairly aggressive cam. It's apples to oranges compared to the valvetrain setup in a LS7. That is one metric that gave the LS engine an advantage over the LT1...the valvetrain is much lighter, easier to rev, and make power due to being able to use stock style rockers, beehive springs, light weight factory valves...etc.
The plunger cup is different...The bodies are different...The part number is different. ......
That's the ridiculous argument some others have made in here. Those are not REAL differences. The bodies are 10 mils wider here and 10 mils narrow there..... doesn't matter. I asked what is the technical difference between an LS6, LS1, and LS7 lifter? Real differences, not BS part numbers. Can I put an LS1/LS6/LS7 lifter all in a stock 1999 valve train and cam and come up with a stock 7.4" pushrod length etc.? If so, they are interchangeable like I stated. I already agreed that race motor stuff and moon rev'ing is a different story.
Most of those LS engines were designed to only rev to about 58-6500rpm with very soft loft lobes and light springs. The ones that rev out to 6800- 7k have light valves for a reason....so yes valve weight and weight over the valve stem is very critical for high rpm. Again if your are building a heads/cam car that is going to rev to 68-7200rpm and use heavier springs with a more aggressive lobe, a lifter with less travel would be a wise investment.
But we weren't talking about high RPM engines, now were we? This discussion started as the LS7 being a viable replacement lifter.
08-29-2018, 04:18 PM
