Need Experienced Engine Builders Advise

[Ranman]

My brother is having some work done to his 68 Corvette by another family member who is pretty proficient with Chevy 350's. He's having a new cam, intake, carb and headers with sidepipes installed. The engine is a basic crate 350 that was in the car when he bought it over 10 years ago. I would estimate HP prior to modifications at 225 - 250 having driven the car. My brother has not driven the car 3000mi since he's owned it. The builder told him that the engine looked brand new inside upon teardown. Here's the issue:

The builder told him that the new Edelbrock cam that was installed was "soft" and consequently every other set of lobes were wiped out upon initial startup. (I don't know what this means) The engine was not run for long and was promptly shut down upon discovery of the problem.

A new Edelbrock cam has since been installed, but now there may be oil pressure problems. The car is now running 15psi oil pressure at idle (not sure what it was before).

QUESTIONS:

1) Has anyone ever heard of a brand new cam being "soft" and consequently wiping out the lobes? Is this possible or is this hogwash? What would typ[ically cause you to wipe out the cam? (I know it's not a roller cam, but I don't know anything from there)

2) What are the repercussions of wiping out lobes in a running motor? Is this a big deal? No big deal? Opinions?

Thanks for any advise anyone can provide. Randy

[BigGrizzly]

When installing a new flat tappet cam the motor must be primed with oil firt then the engine when started must and run for 30 min at over 2000 Rpms if less it WILL wipe out the cam. Also new lifters must be used, with a new cam. If lifters are removed the must be put back in the same hole. If you have low oil pressure the cam will wipe out lobes. As for soft cams if this were true all lobes would wipe. ElderBrock hydraluic cames arn't hardened like solid lifter cams but they are Parkerized. The only time I have had problems is when I didn't follow the rules.

Randy owner of Donzis since 1966

[Rootsy]

Ranman,

i have a friend who JUST went through this scenario in his non-roller 5 litre. he ran synthetic upon startup and break-in which is a NO NO!!!! Comp's directions cleary stated NOT to do this also... and most cam manufacturers also state this. Crane Cams - Failure Reasons (http://www.cranecams.com/instructions/valvetrain/camfail.htm)

After you wipe the cam lobes the motor is FULL of metal in the oil, throughout the whole motor... flushing does ZERO good since it is already between the crank and rod bearings as well as in all of the oil passages and you name it... against my warning and a few other folks he flushed the motor with mineral spirits and straight motor oil to clean it out... He SHOULD have disassembled the motor and cleaned it thoroughly and replaced what was damaged... BUT instead...

he then replaced the camshaft with a new one.. filled and primed the motor with good ole fossil oil and started it up... he broke the camshaft in for the required 20 minutes, changed the oil again (yes fossil oil again) and took a drive... made it about 5 miles before he wiped the bearings... i KID YOU NOT... and this guy is a manager of an engine development group... scary huh...

this last part would likely explain the lack of oil pressure...

[Gearhead99]

Flat tappet cams, hyd and solid, need to be broken in. Run above 2000 rpms for 20 minutes or so. They also should be coated with "cam lube" to help the break in.

Even if you did all this properly, you can still wipe a cam from a problem with the oiling system.

The cam bearings get their oil from the main bearings. If the cam bearings aren't installed correctly or the main bearings lube holes to the cam bearings aren't there or blocked it will continue to wipe cams.

Also, the metal from the failure will be pumped into everything. Should be pulled down and gone over again. I know no one wants to hear that and all they want to do is flush it, but it is better to be safe then sorry.

[RickR]

I follow "The Rules" and still had 2 cams fail during break-in last winter on the Donzi's 454. Had to completely rebuild the engine twice. It was a nightmare. If it wasn't for premium bearings and tuftrided crank I might have ruined the engine. Had to polish crank and replace cam bearings, rod bearings and rings (twice).

Third time around I broke in cam with the outer spring on the OE springs, then after break-in I switched to the springs that came with the cam (a mild Comp Cam K Kit).

Some builders in our area are using a low ratio rocker during break-in on the SBCs.

[Forrest]

Ouch Rick! I break flat tappet cams in just like the Grizz states above and haven't had any problems yet.

I've always wondered how the cams and lifters in new factory-built flat-tappet cammed engines, both marine and in automotive, survive when I'm sure that all of these engines aren't fired up at the factroy and run at 2000-2500 RPMs for 30 minutes.

[GeneD]

I didn't read everyone's posts on this subject, but only the first and the last. Forrest, you have a good point.
I ran into this same problem with my Corvette a few years back. THREE freaking camshafts later, it still wiped out lobes.
I eventually went to another manufacturer and the problem disappeared.

[rong]

Hi Ranman how Winni these days? Yes the cams do need a break in. In the event of aftermarket aggressive cams, valve spring seat pressure is increased. This makes the break in difficult in some cases. Especially when the upper oiling is resricted because a high pressure oil pump is installed. The solution is to break in with stock springs or the ones recommended by the manufacturer. This info has to be researched. Best to talk to the manufacturer. Since this cam had multiple lobes go, then it is either what your engine man said or it was improper breakin. I respect your man's opinion as he's seen it. This is not common but can happen. A hardness test cannot tell as cams are case hardened, so when the cam starts to lose a lobe it will grind most of the way down eventually. Sorry about the motor as that much metal will make a mess of the crank and bearings. One or two lobes and I have saved engines.

[RickR]

My RULES for new cam break-in

Lube cam with Moly Paste (not GEL)
Use a light spring or reduced ratio rocker
One container of GM EOS (poured over valvetrain and cam) w/30weight oil
Pre lube oil with drill
Pre fill carb, filter and fuel lines with gasoline

Starting fluid for initial start up
15 minutes >2000RPMs then 15 minutes varying from 2000 to 2500 (do not exceed 3500RPMs with light springs)

Install correct springs
Change oil and filter and check oil for discoloration
Run above 2000 RPMs for a few minutes
Change oil again at 5hrs

Keep and ear out for rocker ticking and if I suspect a cam is failing remove intake and check visually eek!

Or just forget it and install a ROLLER :rolleyes: