StealthFormula

iTrader: (35)

Hey guys, seeking out some thoughts here. A couple months back I installed a new cam in my C5Z (cam is ground on Comp lobes) and I’ve put about 100 miles on the car since. Got it dyno tuned, performs great. However, since day one, the car has exhibited a whine noise similar to the cam whine noise that people have posted videos of in the past. I contacted Comp Cams, yanked the cam out and sent it back to them to be repolished. They said they haven’t had issues with cam whine for a couple years now since they’ve made micro surface enhancements. They had the cam for about 3 weeks while their R&D department examined it to figure out what the root cause of the issue was. I spoke to Comp today and they mentioned that the surface was measured and is in spec and there’s no sign of chatter on the lobes like I expected. They said the lobes looked burned so to speak so one of their engineers put the cam in a blast cabinet and noticed that all of the lobes had heat in them. They mentioned that they’ve never seen a cam have this kind of heat in every lobe before. Their thoughts are that I may have an issue where my lifters are sliding right over the camshaft and causing unnecessary friction rather than rolling over the lobes like they should. Also mentioned I should be using non-synthetic oil for the first 500 miles to prevent this from occurring rather than running synthetic. Never been an issue for me before. Comp said the cam is junk and they are grinding me a new one free of charge. Needless to say, I’m a bit concerned. The first thing I’m going to do is take a peak at the lifter rollers through the camshaft hole but that will be a few days yet since my car is stored 45 mins away. As much as I’d hate to pull the heads again and lack the time to do so, I’m thinking I better do that to get a good look at those lifters.

What are your initial thoughts here? Bad cam core? Lifter issue? Something else? Anyone ever experience this before?

Additional details of my setup:
-Morel 6504 lifters (new part# for the 5315s)
-7.400 chromoly pushrods (this length gave me ~.065-.070 preload on the lifters which is dead nuts halfway of the full lifter travel)
-Lunati dual springs
-Factory stock LS6 heads with thinner .040” head gaskets
-Stock rockers with trunnion upgrade

Pics:

G Atsma

With those lifters I would suspect the cam was defective. Comp has had their share of issues.

pdxmotorhead

Just curious did you use a break in oil? non synthetic? I know Comp used to need it or the lobes would give up..

tech@WS6store

iTrader: (2)

Its the finish on the cam.
Most local machine shops can polish the journals and lobes out. We have had this issue before fairly recently.
Not saying comp is a bad cam etc but its 100% the surface issues.

StealthFormula

iTrader: (35)

I’m thinking the same.

I did not. I initially ran the car with the existing synthetic oil for a few mins then I drained it and replaced it with fresh synthetic Pennzoil Platinum. I’ve done it this way in the past without issue but today the guy did say no synthetic for first 500 miles.

pdxmotorhead

I had a 406 sprint motor flatten the cam in < 20 minutes, right about the time they took all the good stuff out of the motor oils. Comp actually published a document about lifter and cam failure so did Joe Gibbs and a Roushe if I recall right..

I use Break in oil with a healthy dose of zinc now never had another problem.

Depending on the Alloy of the cam, its the only way to get the surface to burnish/Harden up at break-in as far as I know..

We typically idle the sprint motors for 10 to 20 minutes to get a initial set on the cam and lifters then they get rode hard and put up wet.. 10K rpm tends to break stuff in or just break it..

tug686spd

iTrader: (11)

I'm betting the lifters look no better than the cam, it'd be almost impossible to have damage on one and not the other. What it hurt fist is hard to say, but not likely 16 lifter all failed in a short amount of miles unless there was a oil problem. What was cam specs, lobes, springs and rpm spun up to?

tech@WS6store

iTrader: (2)

There should be 0 need for break in additive on a roller cam with the 2 materials commonly used plus heat treat. Most of the comp cams are 5150 or 8620 just like tsp and cammotion etc.
Comp cams has tried that tactic in the past but how many thousands of cams are installed with 0 issue?
Flat tappet cams are very different. You cannot compare them.
The whining isnt from not using the break in oil. its from the surface finish.

StealthFormula

iTrader: (35)

Here’s a vid I took before I pulled the cam. It’s most noticeable when the rpms are dropping back down to idle:

tech@WS6store

iTrader: (2)

Have the cam re polished at a good machine shop. itll stop making the noise.

StealthFormula

iTrader: (35)

Cam is a 228/232 .614/.600 111. Cam has proprietary FTI lobes. Spun it to mid/upper 6000s on the dyno. Springs are Lunati duals as recommended by the cam designer. Oil pressure has been good.

The second I started the car up I thought cam whine due to the surface finish. I just don’t understand why they wouldn’t have just repolished it and sent it back to me as I asked rather than examining it for weeks and ultimately deciding to grind me a new one if there wasn’t potentially more to it.

I’m gonna send the new cam over to Cam Motion for a polish for good measure before I install it.

tech@WS6store

iTrader: (2)

That same issue has happened before to a customer. save yourself some time and just get it reground. Propriety lobes mean nothing when the cam whines imo.

cookseyb

Get a Texas Speed Cam, they gave up ,on Comp and now grind their own..

G Atsma

Texas Speed, as above, or Cam Motion. Either will give you a good quality, well-finished core AND back it up.

jlangley

iTrader: (8)

This is the streetsweeper Ht cam from FTI? I was impressed by the numbers from this cam but didn't realize it was supplied by comp.

cookseyb

I visited Texas Speed last week, What a GREAT bunch of folks! Got a grand tour of their facilities and was really impressed with their customer service and attention to detail!

StealthFormula

iTrader: (35)

Next time around I’ll spare myself the drama and avoid Comp. Yes, I’ve got the Streetsweeper HT. Car put down some crazy good numbers with it and it runs its *** off. I’m a big fan of Ed’s cams personally. That’s part of the reason I don’t want to change it plus I spent $465 for the cam and another $400 to dyno tune the car with this cam so I certainly don’t want to spend all that money twice. Hopefully the new cam with a repolish from Cam Motion will do the trick. I am just concerned after what Comp told me that I may have other issues.

I’m hoping Cam Motion and some other valvetrain gurus chime in with their thoughts given the pictures and what Comp had to say.

tech@WS6store

iTrader: (2)

Im telling you exactly what happened to a customer of ours and exactly how he fixed it. The second cam sent from comp whined also so he took to machine shop and had it polished. Runs fine now.

And spending nearly $100 more on a cam seems kinda odd. Its basically just another 228/232 really. I know he used to like to use lunati and their lobes arent published and they are known to be a bit more aggressive than most of the comp lobes. They had a magazine comaprison showing as much with ls3 cams quite a while back. It makes quite a bit of valvetrain noise also from the video.

StealthFormula

iTrader: (35)

I’m taking your advice and will do the same and get it repolished. Hopefully all is well then. I’m just a little baffled yet as to why I’m getting told what I am from the engineers at Comp. Perhaps it’s just a way to redirect the issue to not seem like it’s their fault.

qweedqwag

+1 for TSP they are friggen awesome.