ls7 lifter failure
Melting Slicks
Joined: Dec 2003
Posts: 3,315
Likes: 17
From: Near Jacksonville Fl.
The only checks you can make for case depth are destructive to the surface.
You can check on the side of the lobe but it will not tell you how much was ground off the profile during finish machining.
I suspect some amount of failures are caused by improper break-in or valve train control but most are QC issues.
OEM parts are checked randomly so many per run to sample case depth but since it is destructive most aftermarket companies let you do the testing in your engine.
Instructor
Joined: Sep 2006
Posts: 159
Likes: 0
From: Rantoul IL
One word: Morel
LS7 lifters are a stock lifter and are not a hi-performance lifter. We see them fail a lot with aftermarket cams and springs. I would also avoid the "caddy" lifters as people have trouble with them as well and properly matching things up.
Lifter trays wont do a thing if the pin starts coming out of the wheel.
LS7 lifters are a stock lifter and are not a hi-performance lifter. We see them fail a lot with aftermarket cams and springs. I would also avoid the "caddy" lifters as people have trouble with them as well and properly matching things up.
Lifter trays wont do a thing if the pin starts coming out of the wheel.
Thread Starter
Intermediate
Joined: May 2008
Posts: 35
Likes: 0
From: Orlando FL
RagtopC5,
This is what an improperly hardened cam lobe will look like. It will cause the lifter roller to fail and the lifter is normally the first item to let you know you have a real problem, much like what happened in your case.
Hope the rest of the repairs go smoothly for you.
This is what an improperly hardened cam lobe will look like. It will cause the lifter roller to fail and the lifter is normally the first item to let you know you have a real problem, much like what happened in your case.
Hope the rest of the repairs go smoothly for you.
Safety Car
Joined: Jul 2005
Posts: 3,572
Likes: 9
From: Jackson Tn
St. Jude Donor '06-'07-'08-'09
Le Mans Master
Joined: Jun 2006
Posts: 6,979
Likes: 31
From: Wichita KS
Got about 12k HARD miles on my LS7's but I pulled the vlv cover off about 3 months ago due to a somewhat loud ticking on the drivers side to find that the back 2 rockers (#8 pistion I think) was NOT getting oil for a good 5 mins after a cold start-up, so I may be changing my lifters soon. Morels will be my next set
Former Vendor
Joined: Apr 2006
Posts: 2,470
Likes: 2
From: Portland OR
St. Jude Donor '10-'11-'12
^^
Some people push things harder than others and need the extra protection of a superior part. Not sure why that causes such heartache for some people on here but it is what it is.
We see failures others don't maybe because we deal with hard core racers maybe more often than others do. So we see things and use things that make sense for the application.
Are Morels needed in every setup of course not but if your pushing things with an aggressive setup you need valve-train components that are made to handle it. The valve-train is extremely important and I like to spend the money there and save elsewhere. Maybe its overkill to some but I like to be safe where aggressive setups and drivers are concerned.
What that level is a matter of opinion and I like to play it safe. Is the Morel more money ? Yes a lot more but your getting what you paid for and I don't have a problem getting what I paid for or offering something that is worth the money.
Why do some people buy AFR and TFS heads and others buy Patriot? The AFR and TFS cost a lot more than Patriot heads.
Some people push things harder than others and need the extra protection of a superior part. Not sure why that causes such heartache for some people on here but it is what it is.
We see failures others don't maybe because we deal with hard core racers maybe more often than others do. So we see things and use things that make sense for the application.
Are Morels needed in every setup of course not but if your pushing things with an aggressive setup you need valve-train components that are made to handle it. The valve-train is extremely important and I like to spend the money there and save elsewhere. Maybe its overkill to some but I like to be safe where aggressive setups and drivers are concerned.
What that level is a matter of opinion and I like to play it safe. Is the Morel more money ? Yes a lot more but your getting what you paid for and I don't have a problem getting what I paid for or offering something that is worth the money.
Why do some people buy AFR and TFS heads and others buy Patriot? The AFR and TFS cost a lot more than Patriot heads.
Safety Car
Joined: Jul 2005
Posts: 3,572
Likes: 9
From: Jackson Tn
St. Jude Donor '06-'07-'08-'09
no offence 99blancoss but when you make statements like in this thread and your signature is an advertisment to sell the parts your talking about ..... it just looks like your pushing your parts.
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Former Vendor
Joined: Apr 2006
Posts: 2,470
Likes: 2
From: Portland OR
St. Jude Donor '10-'11-'12
Well I didn't put the lifter in the sig until I was accused of pushing the part..LOL call it my twisted sense of humor.... I'll take it out.
All I am saying is that there are times when you need more than a factory production part.
I appreciate your being respectful. I'm not here to take advantage of anyone. I try to offer great deals on certain things that I can and be helpful when I can. Its hurtful when people accuse me of underhanded things, the whole reason I am in business is to help. I was a victim and didn't want to have it happen to other people so I decided to open up shop and take on a few things that I new I could do/provide a better product for a reasonable cost so someone wouldn't feel like I did after having spent the money to achieve mediocre results. Sounds corny I know, but its the truth. We've been in business for a few years now and have helped quite a few people.
All I am saying is that there are times when you need more than a factory production part.
I appreciate your being respectful. I'm not here to take advantage of anyone. I try to offer great deals on certain things that I can and be helpful when I can. Its hurtful when people accuse me of underhanded things, the whole reason I am in business is to help. I was a victim and didn't want to have it happen to other people so I decided to open up shop and take on a few things that I new I could do/provide a better product for a reasonable cost so someone wouldn't feel like I did after having spent the money to achieve mediocre results. Sounds corny I know, but its the truth. We've been in business for a few years now and have helped quite a few people.
Safety Car
Joined: Jul 2005
Posts: 3,572
Likes: 9
From: Jackson Tn
St. Jude Donor '06-'07-'08-'09
to get this thread back on topic
I looked up the specs on the OP's cam and it's not that big. If this is the specs I would think LS7 lifters would have no problem with this cam. I can understand running LS7 lifters with a big cam with big springs may be asking too much from this lifter but this is not a big cam. I would even think patriot gold dual springs would be over-kill. Maybe it's the ramp rate that's the killer here.
Thunder Racing - 220/220 .551/.551 114 LSA
Ls6 Cam specs - 204/218 .550/.550 117.5 LSA
I looked up the specs on the OP's cam and it's not that big. If this is the specs I would think LS7 lifters would have no problem with this cam. I can understand running LS7 lifters with a big cam with big springs may be asking too much from this lifter but this is not a big cam. I would even think patriot gold dual springs would be over-kill. Maybe it's the ramp rate that's the killer here.
Thunder Racing - 220/220 .551/.551 114 LSA
Ls6 Cam specs - 204/218 .550/.550 117.5 LSA
Last edited by printmanjackson; Aug 2, 2010 at 02:25 PM.
Former Vendor
Joined: Apr 2006
Posts: 2,470
Likes: 2
From: Portland OR
St. Jude Donor '10-'11-'12
I agree and you need to look at sustained rpms as well. Quicks bursts are one thing but sustained hi rpms are another. So application should play a part in the selection process as well.
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
to get this thread back on topic
I looked up the specs on the OP's cam and it's not that big. If this is the specs I would think LS7 lifters would have no problem with this cam. I can understand running LS7 lifters with a big cam with big springs may be asking too much from this lifter but this is not a big cam. I would even think patriot gold dual springs would be over-kill. Maybe it's the ramp rate that's the killer here.
Thunder Racing - 220/220 .551/.551 114 LSA
Ls6 Cam specs - 204/218 .550/.550 117.5 LSA
I looked up the specs on the OP's cam and it's not that big. If this is the specs I would think LS7 lifters would have no problem with this cam. I can understand running LS7 lifters with a big cam with big springs may be asking too much from this lifter but this is not a big cam. I would even think patriot gold dual springs would be over-kill. Maybe it's the ramp rate that's the killer here.
Thunder Racing - 220/220 .551/.551 114 LSA
Ls6 Cam specs - 204/218 .550/.550 117.5 LSA
It is a miss conception that spending more money will get you a better system. You can spend all the money, but if the parts are mismatched it is all for not. The valvetrain system isn’t a system that you can take fits all parts, stick it together and expect nothing but good things to happen. If you purchase aftermarket parts make sure you are dealing with a company that knows which components to pick to make a working system. Make sure they don’t tell you it is the best because it cost more money, but that it is the best part to match with the other components to complete the system. For a good valvetrain system it needs to be validated with all components throughout the planned operating range, otherwise, you become the validator and in most cases at your own expense. 
Thread Starter
Intermediate
Joined: May 2008
Posts: 35
Likes: 0
From: Orlando FL
Well it was a soft cam for sure. I need to cut it up to put it in the hardness testing machine which I have not done yet, so I don't have an exact Rockwell C number. The technician said it is definitely below HRC 40 based on how easy it is to put a deep scratch in any lobe. Examining it under 7x magnification I can see 10 other lobes with cracks appearing, very close to having big chunks flake off. Cause of lifter failure was definitely a chunk (or a couple) flaking off the cam and then the cam beating up the lifter roller.
They have some very slight marring on the rollers but the cam looks much worse
So can anyone recommend a cam similar to the specs I had that will actually be made correctly and not trash my engine? Would my patriot gold dual springs be ok with an ls6 cam or should I get ls6 springs? I hate doing all the work correctly to have a failure due to inferior parts. I plan on using ls7 or caddy racing lifters since the lifter failure was the cam's fault and I'm not using a monster lift cam or driving at high rpm all the time.
So can anyone recommend a cam similar to the specs I had that will actually be made correctly and not trash my engine? Would my patriot gold dual springs be ok with an ls6 cam or should I get ls6 springs? I hate doing all the work correctly to have a failure due to inferior parts. I plan on using ls7 or caddy racing lifters since the lifter failure was the cam's fault and I'm not using a monster lift cam or driving at high rpm all the time.
Last edited by ragtopC5; Aug 8, 2010 at 12:09 PM. Reason: additional info
Le Mans Master
Joined: Jun 2002
Posts: 8,352
Likes: 103
From: In the pit, trying to love someone.
If you are using an LS6 cam, use LS6 springs. There is no reason to run anything different, and they will last you a very long time. Stock replacement LS7 lifters would be a fine choice.
Safety Car
Joined: Jul 2005
Posts: 3,572
Likes: 9
From: Jackson Tn
St. Jude Donor '06-'07-'08-'09
Race Director
Joined: Sep 2005
Posts: 11,060
Likes: 291
From: Pasco WA
I'm no expert, but it appears that the cam is the cause of your failure. The mixing of compatible components could also be partially to blame. The Patriot twins are way more spring than that cam needs, for one. Ask Vettenuts, or AUEngl about the beehive springs they use in roadracing, and milder lift cams. I just replaced a Crane cam, which gave me no problems, with a Comp ground cam from A&A to go with my blower, so I hope it's not subject to the problem you had. When I removed the Crane cam, everything looked perfect, and this was using the CRLs, that I installed with the Crane cam. My lifter trays were left original, because they didn't have the stamped numbers that're supposed to be bad. I hope to have a motor built someday (forged) and I'll probably use Tom Wong's advice on which combo to use. I wouldn't use LS6 springs as Mike suggested, simply because of their known failures.
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
If the OP wants to stay with stock size cam, buy it from any of the forum supporters that sell the GM Performace products. The cams are process checked to meet hardness and other requirements.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
To the OP, the lift of your cam has me very suspicious it was a Crane grind and not a Comp. All the Cranes used 0.551" lift on the lobes.
If it is Crane, I had a similar problem but caught it before it did damage. However, I did have to have my Morel lifters rebuilt because of the cam. I found out when I was upgrading the cam and heads to the AFR setup I now run, and when I found the issue with the Morel lifters I contacted Morel and shipped them both the cam and the lifters for further testing. The final answer was the cam was the issue so it was a good thing I upgraded the setup or I wouldn't have found it until the damage was done. While this doesn't help your current issue, it may further validate your final answer as to the cause.
If it is Crane, I had a similar problem but caught it before it did damage. However, I did have to have my Morel lifters rebuilt because of the cam. I found out when I was upgrading the cam and heads to the AFR setup I now run, and when I found the issue with the Morel lifters I contacted Morel and shipped them both the cam and the lifters for further testing. The final answer was the cam was the issue so it was a good thing I upgraded the setup or I wouldn't have found it until the damage was done. While this doesn't help your current issue, it may further validate your final answer as to the cause.
