Cam pitted.. Is the lifter trashed?
#1
Cam pitted.. Is the lifter trashed?
Pulled the cam tonight to find two bad lobes, pictured below ... I tried to examine the lifters with a borescope and all seems well.. However, I have my concerns (the borescope is only so good). I can't rotate the rear lifters or anything to inspect the whole roller so I'm looking for advice from people with experience. Do I need to actually tear the heads off and replace the lifters or just replace the cam and go for it? I had no issues/noises before tear down..
Keep in mind, this was a cheap cam so I was kinda asking for these issues.. I know that already and now I'm asking for help moving forward.
Thanks
Keep in mind, this was a cheap cam so I was kinda asking for these issues.. I know that already and now I'm asking for help moving forward.
Thanks
#2
TECH Senior Member
iTrader: (26)
i'm probably one of the cheapest, sloppiest ***** on here....
and i would pull the heads and replace the lifters.
I'd also check the bearings and such, that metal went somewhere.
also searching for a root cause would be a good idea. bad spring? lifter preload wrong? inquiring minds want to know!
and i would pull the heads and replace the lifters.
I'd also check the bearings and such, that metal went somewhere.
also searching for a root cause would be a good idea. bad spring? lifter preload wrong? inquiring minds want to know!
#6
Ok....ok I guess that was a stupid question.. I'm already this far into the engine, I'm just going to do it right and replace the lifters. Its only a few more bolts... So it seems like LS7s are the way to go around here?
Thanks for the help guys
Thanks for the help guys
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#12
TECH Resident
My cam was worn.
This is what my lifter looked like.
Pull the heads and take a look at the lifters, yours may not be as bad as mine, but something not good is happening to create than on your cam.
Good luck with it.
This is what my lifter looked like.
Pull the heads and take a look at the lifters, yours may not be as bad as mine, but something not good is happening to create than on your cam.
Good luck with it.
#13
Alright guys, I pulled the heads and lifters today... I found most lifters looking ok, with no severe damage. There is scuffing on a few of them and warrants changing them out. The trays were also pretty wore out. I'll post pictures tomorrow when I get back in the garage and let you guys be the judge... I'll have new lifters, trays, gaskets, and bolts to start reassembly tomorrow. Also gonna change the oil & filter for safe measure..
Thanks for the input, it is appreciated
Thanks for the input, it is appreciated
#14
Staging Lane
Don't forget to at least check your current springs if you're not planning on replacing them. As for what lifters to use, GM is now selling a set of Cadillac racing lifters that are good to 8000 rpm. They're not cheap, mine were $289 from Summit, but they're OEM racing parts. P/N 88958689.
#15
TECH Resident
Pulled the cam tonight to find two bad lobes, pictured below ... I tried to examine the lifters with a borescope and all seems well.. However, I have my concerns (the borescope is only so good). I can't rotate the rear lifters or anything to inspect the whole roller so I'm looking for advice from people with experience. Do I need to actually tear the heads off and replace the lifters or just replace the cam and go for it? I had no issues/noises before tear down..
Keep in mind, this was a cheap cam so I was kinda asking for these issues.. I know that already and now I'm asking for help moving forward.
Thanks
Keep in mind, this was a cheap cam so I was kinda asking for these issues.. I know that already and now I'm asking for help moving forward.
Thanks
#16
Sorry for the delay, I've been working around school and such.. Anyway, I haven't taken any good pictures of the lifters yet, those are soon to come.
I ended up replacing the lifters, trays, pushrods (for correct length), and camshaft. I also ordered a Straub trunnion kit and installed it while I was waiting for other parts. Once finished, I changed the oil and filter, ran the engine for a little and then changed the filter again.
I ended up settling with a cam between the two I had previously listed. I decided upon a Howards 222/225 .561/.578 112+4. From startup, it immediately wanted ~20% more fuel than the previous cam and pulled ~20kpa more vacuum. From this, I believe the old cheap cam was not as advertised and likely not ground correctly from the beginning... The two cams are a little different but is it enough to cause these differences?
Old cam: 218/228 .560/.560 112+4 (supposedly)
I ended up replacing the lifters, trays, pushrods (for correct length), and camshaft. I also ordered a Straub trunnion kit and installed it while I was waiting for other parts. Once finished, I changed the oil and filter, ran the engine for a little and then changed the filter again.
I ended up settling with a cam between the two I had previously listed. I decided upon a Howards 222/225 .561/.578 112+4. From startup, it immediately wanted ~20% more fuel than the previous cam and pulled ~20kpa more vacuum. From this, I believe the old cheap cam was not as advertised and likely not ground correctly from the beginning... The two cams are a little different but is it enough to cause these differences?
Old cam: 218/228 .560/.560 112+4 (supposedly)