Welcome to the Corvette Forums at the Corvette Action Center!

Cam Failure


Well-known member
Jan 9, 2003
1973 DK. BLUE CPE.
For the past 18 months I have been doing a frame off resto on a 73. I had the engine assymbled by a reliable mechanic, as I had plenty of work to do on frame, suspension, body etc.
The short of it is I built a 383. Sportsman II heads (ported), Comp 280H cam, Comp lifters, Comp roller tip rockers. RPM intake(ported), 770 Holley Street Avenger, MSD 6a ingition.
With less than 100 miles on the engine, the #1 cyl exhaust and the #8 intake lobes and lifters are complety wiped out. Several of the other lifters and lobes show excessive wear.
I did cam breakin procedure as recommended by Comp and used a drill to circulate the oil before cranking. After breakin I readjusted the valves and did notice the #1exhaust and the #8 intake to be loose. Yesterday after a 20 mile drive I checked the valve adjustment and found these could no longer be adjusted. Pulled the cam and found the above.
Any info or advise on what could cause this kind of failure would be appreciated.
Do I just install new cam and lifters.
Todays plan is to drop the oil pan and check bearings, crank, etc

For whatever reason, it sounds like the cam lobes didn't recieve the correct hardening process. I would have no idea why. What do the bottoms of the lifters look like, did they also wear excessively in that short time?
I would make a call to where you purchased the cam to see if they can assist you in contacting Comp Cams. I'm sure the manufacturer would want to hear about this, and probably would like the cam returned along with the lifters and a short narrative from you on your installation. That way they can test the components and find out why they failed prematurely, and correct whatever process failed.
Oh yeah, and I'm sure they will give you a replacement cam and lifters, that would seem like the right thing to do.


Yes the lifter were dished out on the #1 and #8 cyl. lobes effected. Severl of the other lifters and lobes were starting to show wear and some looked in perfect condition.
Yes I have thought about contacting Comp Cams, however I am debating switching brands.
Also I am wondering if something besides just a bad cam caused this as I don't want to do this again

I would contact Comp Cams. I ran another cam one time and had a couple of racers tell me they wouldn,t use this other companies lifters. I thought-yeah right like I'm going to mix one cam with other lifters. Long story short- a lifter failed and screwed the cam up(fortunate that was all) I had always used Comp Cams before then, and replaced the "other" cam with a Comp Cam which is still in there and running like it should. The only two cams I can vouch for would be Comp Cams which I run and have almost always run, and a Crane cam which about two dozen people I know run. The biggest reason for cam failure is improper break-in. Other than that, I wouldn't know what would cause it. It would seem hard to believe Comp Cams let a bad one out the door, but it could happen(no ones perfect)so I would contact them.
Yes I know Comp has an excellent reputation and I will be contacting them, but this sure leaves a bad taste in your mouth.
I was very anal about the break in procedure, but this appears to have started during break in.


PS Working on the car and checking the computor every 30 minutes or so.
73383 said:
... this sure leaves a bad taste in your mouth.
Dennis, I know exactly where you're coming from, but give Comp a chance to make good with you. If you don't give them the opportunity then you are certainly out for the cost of the parts, and will still need to purchase replacements.
Perhaps advise them that you are hesitant about trying Comp again because this was such a negative experience, but I would still urge you to contact them and see what they can do to help.
What could it hurt?...and it may even help.

Best of luck with whatever you decide.
Thanks Heidi

I will contact them and will probably use another comp cam, but the cost of a cam and a set of lifters is cheap compared to the amount of work to install.
One reason I am kind of down in the mouth about this is, I have the car ready for the first primer coat and was looking forward to paint very soon.

Just dropped the oil pan. every thing looks good on the bottom end.

Unfortunately, I've read several posts lately dealing with exactly the same failure that you've suffered with your Comp Cam. I personally have ran an HE268 in my '73 L48 for 5 years with out a single problem. Great little cam for the application. Do give Comp the opportunity to respond, but be aware that there seems to be a growing concern amounst the community about the recent failures. The gentleman that's building the new SB for my '73 project is hinting very strongly that he would much prefer to use a Crane Cam and valve train components.

You'll find as many proponents of CompCams as you will opponents.

I have read some of the negative comments recently about Comp Cams. I have an XE 262 that has about 2000 miles on it and it still runs strong. So far so good. I believe if I were putting another cam in I would not hesitate to give comp another shot at it. In fact I have been considering doing this just for kicks.
Comp Cams stuff is as good as you can buy!!!!!! Its possible you got a bad cam, or a bad set of lifters, BUT check EVERYTHING ELSE before you point a finger at Comp Cams. If you check all else and find nothing, Then NICELY, call them and talk to them about it!!! Good Luck!!!!!:(
Do you know for sure what kind of (and how much) cam assembly lubricant the guy used who assembled the engine? Did he use all new lifters with the new cam? 99% of cam failures (especially as early as this one failed) are a result either of 1) Inadequate/incorrect cam assembly lube, and/or 2) Improper break-in (excessive cranking to start it the first time, allowing it to idle, shutdowns during break-in, etc.). Some builders also go way overboard on valve spring pressures vs. what the cam manufacturer recommends, and that just makes it worse.

I would also add to JohnZ's items: Wrong valve springs and / or valve initial adjustment wrong. Also wrong push rods lenght.

Having said that, my FACTORY L81 cam went flat 33,000 miles, but this one was not CompCams (at least I believe it was not). Chevy returned me 66% of the cost through an agreement letter in existance then.
bummer the cam is dead from the get go. when installing the oil plugs in the back of the motor around the cam journal, how far in did you tap and run the plugs??? it is very easy to run the plugs in to far and cut the oil supply to the cam. i would pull the motor and double check this is not the problem. the decription of the failure seems all to familiar, a bad cam is one thing, but wasted lifters to boot seems like no lube at all. were any of the parts blued from heat?? if so, you're not getting oil for some reason. lastly, when you prime the oil pump, get an old distributor from the junk yard and use it after grinding the teeth off the gear. the shaft makes a seal to the block and forces the oil into the gallies priming the engine instead of recircing oil from the pan thru the pump and back to the pan. best of luck getting things back in the good, Brian.
Well the good news is, my builder and parts supplier is getting me new cam and lifters at no charge. Spoke with him yesterday.
As I said before I did not put the engine together, I had a local speed shop put it together. All parts were new, except for the block. I gave them general instructions, 383 engine 430-450 hp. We selected parts to build.
The cam and valve train components are:
CAM comp cam 280h lift .480
LIFTERS comp cam hyd 812
PUSHRODS comp cam standard small block 7.8 in
ROCKERS comp cam magnum roller tip rockers 1.52

We used sportsman II head and hogged em out good. The head came with valves and springs.
Dug up my reciepts and went to the garage and measured the springs.
The springs are 1.44 dual with 125lb seat preasure. I have researched all evening and cannot find out what the over the nose preasure is. I think I remember reading it was 369lbs or 389lbs. If no one knows I'll call World Product. If this is so is it the probable cause.

Thanks for all the help
73383 said:
Well the good news is, my builder and parts supplier is getting me new cam and lifters at no charge. Spoke with him yesterday.
You know it sucks that your having the trouble to start with but it's very refreshing to her that the supplier is doing right by you.

Corvette Forums

Not a member of the Corvette Action Center?  Join now!  It's free!

Help support the Corvette Action Center!

Supporting Vendors


MacMulkin Chevrolet - The Second Largest Corvette Dealer in the Country!

Advertise with the Corvette Action Center!

Double Your Chances!

Our Partners

Top Bottom