big_mike_eu

Hi everyone, this is a continuation of a thread I started several months ago (https://www.corvetteforum.com/forums...e-noise-4.html).

I thought it would be better to start a new thread with an appropriate title. In short, one day I noticed a loud ticking noise which I have not heard before. Got the car home and began tearing it apart. Couple of day ago I believe I got down to the cause as I pulled the heads and lifters. Below are two bad lifters that came out of the intake valves on cylinders 4 & 6.

What could've caused this? Thankfully the wheels are spinning normally.

I haven't pulled the cam yet, but it doesn't look too bad from what I can see.

What is the best way to clean the head/block mating surface?

MTPZ06

I'd be shocked if that cam is salvageable.

Unreal

Cam is trashed.

Valve train issues, skipping the lifters on the lobe. Not enough spring or valve train instability.

If it is stock, poor oil, oiling system issue. Lifters do go out, especially on ls7s, but typically one. More than one indicates something took them out.

Undy

It could be one of GM's infamous soft cams too. It's a bit of chicken and the egg. Which came first?? Soft cam eating the lifters or bad lifters taking out the cam?

Either way, both are toast.

FSTFRC

Bet that cam is trash, same thing happened too an aftermarket cam in my car a couple of years ago.

Unreal

Seems to be a more common issue as ls7s get older. I know CPR just did one last week and had another not long ago.

rio95

Cordes Performance Racing

I've seen a trend on the ls7 lifter thing. You can always chock some of it up to there will always be a percentage of parts that fail early on in their life cycle. But these are things i have started to notice that will take them out.

1) wrong pushrod length, time and time again we see cams installed with the wrong length. This will kill a lifter
2)long oil change intervals
3) car show guys who will get in their car rev the crap out of it and shut it off. No joke I see this a lot and than see these types come in and go but I don't even race it...
4)people who rip on it consistently without letting oil get to temp.

​​​​

rio95

Les

But...but...it's so cool to sit there and free rev the snot out of your engine to impress total strangers! When I see people here talking about doing that I just

Michael_D

If the engine was completely stock, then the camshaft is most likely the initiated failure node. If the engine is not stock, and someone has messed around with the valve train, then I'd suspect improper valve train set up.

LS7 and Caddi lifters are not the problem. It's the monkeys screwing around with them that's the problem.....

big_mike_eu

Car is stock with the exception of WCCH Stage 2 (without milling), SS exhaust valves and PAC .625" springs. I did not do the head removal/install when I got the heads sent to WCCH. Oil has been changed at 3k miles or less. Always used Mobile 1 5w-30 Extended Performance. Last oil change I used Mobile 1 0w-40 Euro formula. Do you think the shop that did the removal/install of the heads did not set the reload correctly?

Haven't looked into those. Why would you go with them over the LS7 lifters? I need to start ordering parts soon, lifters was going to be one of the first items on the list.

1) I have the stock cam still, so I believe the pushrods I took out should be factory length.
2) I'm very particular on that one, usually I change oil early. On this car I've only done 1 oil change at 3k miles, all others have been earlier.
3) Hahaha does not apply here
4) Always wait until I get 100* before I start driving, and over 150* before enjoying

Engine is stock except WCCH stage 2 (no milling), SS exhaust valves and PAC .625" strings. Do you think the shop that removed/installed the heads might have done something incorrectly?

I've heard bad things about the Caddy lifters, but I was intending to get new LS7 lifters and trays. Which lifters would you recommend?

I hope Jason from Katech pitches in as I am intending to run the torquer 110 and hope to get his input on this. I have to take out the steering rack and work my way to the cam. Its single digits today, but hopefully in the next couple of weeks I can share some pictures of the cam. I am kind of concerned where the pieces that came off of the lifter wheels went. Is that something I should be worried about?

MTPZ06

You may very well be just another unlucky owner that unfortunately has to deal with the "soft cam" issue. Sometimes **** just breaks...

Unreal

Or SS valves with those 625 springs just were not up to the task, and the extra force for the higher springs took out the not so great stock cam. More spring, more pressure on lifter, more pressure on cam.

MTPZ06

First thing I thought, but he said the lifters were from the intake sides.

big_mike_eu

If this is one of the "soft cam" cases, how likely is that the metal that came off of the cam and lifers will cause damage elsewhere?

That was actually the first thing that came to mind as I pulled out the lifters, but then realized that both of them are on the intake side. Facing the head mounted on the block, both of them were the left lifter for the corresponding cylinder.

rockinSeat

Do the z07 and 2012 and later cars with Zr1 oil cooler ever have bad lifters? I swear that cold oil can't be good for something.

Unreal

Both intake valves starts to point to heavy intake valves causing issue. When cam comes out will be interesting to see if it is mostly intakes, or all lobes.

big_mike_eu

This makes sense, but I have the stock titanium intake valves. So logically the springs should be able to handle the weight of that valve with stock cam. This sure has me scratching my head as to what happened. Just hope no more damage is done. Still single digits here. Last night it was -7*, so no work on the car.

Is it true that the oil pan needs to be dropped a little bit for the oil pump to come out on the LS7?

Unreal

My bad then. Yah, I thought it was SS intake valves. The Ti should not be an issue at all.

I've done the oil pump with and without touching pan. If you touch it, just need to loosen the bolts a little, not enough for it to even noticably move. I've also done it without successfully but you run the risk of ripping the gasket.