Is This Camshaft Reusable? Or Too Pitted?

[jmo2610]

Will it be less power than the stock DOD that I’ve been running? Or will the non-DOD 5.3 have more power than my current setup, but a proper 6.2 can would be the best?

 

[BYaggie]

This is in relation to my engine knock thread. Before I pull the other head, I'd love y'all's opinion on this cam. This is a pretty expensive decision for me to go any further (especially if not needed). Is this cam too pitted to reuse?

Note: The other thread relating to cams in this forum didn't have a pic that would load, so I didn't have anything to compare to. Sorry for a similar question.

When in doubt, throw it out!

 

[West 1]

This is a roller camshaft, not a flat tappet camshaft, if I could feel anything with my fingernail I might give it a slight buff with emory cloth to make sure there are no protrusions. Clean it, oil it and install my new lifters. Yes I have done probably a dozen GM repairs in the last couple years with failed AFM lifters. A roller lifter needs a smooth surface but not a perfect surface. No gauges, scrapes, dents, no appearance of the lobe losing its shape I would and have run them. Roller cams are much more forgiving. If your ramps or nose on the cam lobe have any damage that would keep a lifter wheel from rolling perfectly smooth over it than of course get a new camshaft. If you want an upgrade get a new cam. If you just want it to run and not knock make sure they are smooth and install new lifters. With one head off you are very close to being able to do a valve job. I am more concerned about those heads dropping valve seats than I am about cam lobe wear. A valve Job with new seats would let you sleep better at night. The 6.2L is known to drop valve seats which can break a piston and end your engines life. Just a consideration.

 

[jmo2610]

First off, this whole job sucks. Second, do I have to relieve the tension on the timing chain in order to remove the timing chain? I've seen multiple videos, all doing something different. And also, so far, I've had a whale of a time pushing that tensioner far enough to get an little allen wrench in the holes to hold it.

 

[West 1]

First align your timing sprockets so they are in the perfect position, marks aligned properly. This sets you up for the future install, crank and cam in proper position.
I have done several, I don't remember fighting any of them.
Remove the bolts holding the cam sprocket to the cam and slip it off. On install you reverse the procedure with the new tensioner in place. removing the tensioner does not allow removing the timing chain without removing the cam sprocket first.

Sounds like you have decided on a new camshaft?

 

[jmo2610]

First align your timing sprockets so they are in the perfect position, marks aligned properly. This sets you up for the future install, crank and cam in proper position.
I have done several, I don't remember fighting any of them.
Remove the bolts holding the cam sprocket to the cam and slip it off. On install you reverse the procedure with the new tensioner in place. removing the tensioner does not allow removing the timing chain without removing the cam sprocket first.

Sounds like you have decided on a new camshaft?

I did. Doing the entire delete. Not particularly having a good time, but the truck is in great shape otherwise, and my wife loves it, so I went for it. Even though this is a newer generation, I was referencing this video (timestamped) where he releases the tension before removing the cam sprocket. I saw another guy try that and break the tensioner. I've seen others that didn't really clarify whether they released the tension or not.

 

[West 1]

The tensioner is a wear part so I was assuming you would replace it?

 

[West 1]

If this is all new to you there are a few things to be aware of. Torquing the NEW head bolts has several steps. I found the easiest and least chance of messing this up is to torque all bolts to the first step specs. Then take a paint pen, I use white so it is easy to spot as I work. Mark all your bolts straight up so you know where you start with future steps. I don't remember the angles they ask for next but this allows you to see that each bolt has moved to the new position as you torque the bolts. Follow the torque pattern and steps advised exactly. It is 100% necessary to get the heads properly torqued. The paint marks save your bacon when something happens and you have to stop and leave the job in the middle of torquing the heads. The head torque sequence is very unique. And a pattern has to be followed so they get torqued in proper sequence. Torque to yield bolts have a very specific torque spec and must be followed exactly since you are torquing the bolts till they are starting to break. Hence the term, torque to yield. This is done to avoid over torquing the heads. Over torquing is proven to Distort your cylinders which affects ring seal so be smart. Follow the book on these steps and expect it to take you at least 1/2 hour per head. These are not old school engines and need special care to make them work.

 

[Geotrash]

If this is all new to you there are a few things to be aware of. Torquing the NEW head bolts has several steps. I found the easiest and least chance of messing this up is to torque all bolts to the first step specs. Then take a paint pen, I use white so it is easy to spot as I work. Mark all your bolts straight up so you know where you start with future steps. I don't remember the angles they ask for next but this allows you to see that each bolt has moved to the new position as you torque the bolts. Follow the torque pattern and steps advised exactly. It is 100% necessary to get the heads properly torqued. The paint marks save your bacon when something happens and you have to stop and leave the job in the middle of torquing the heads. The head torque sequence is very unique. Something like this: And a pattern has to be followed so they get torqued in proper sequence. Torque to yield bolts have a very specific torque spec and must be followed exactly since you are torquing the bolts till they are starting to break. Hence the term, torque to yield. This is done to avoid over torquing the heads. Over torquing is proven to Distort your cylinders which affects ring seal so be smart. Follow the book on these steps and expect it to take you at least 1/2 hour per head. These are not old school engines and need special care to make them work.

To this I will add, make absolutely certain that your head bolt holes in the block are completely clean and dry before you install the bolts. You don't want any coolant or debris in there.

Also, I used ARP head bolts because they're reusable and can be torqued to the correct value directly, without having to mess with angles like the factory torque-to-yield bolts require, as described above.

 

[j91z28d1]

First off, this whole job sucks. Second, do I have to relieve the tension on the timing chain in order to remove the timing chain? I've seen multiple videos, all doing something different. And also, so far, I've had a whale of a time pushing that tensioner far enough to get an little allen wrench in the holes to hold it.

sounds miserable, I don't wish this job on anyone.

I think I'll end up pulling the engine when mine finally goes.


for the timing chain, I thought it was common in the ls world to ditch the tensioner for the ls2 type. it's just a cheap plastic block that bolts on and gives the chain something to bang around on. early ls1s didn't have any tensioner. if getting rid of the vvt, that seems like it would be the most reliable?