[dittoz]

So as I sit here reading the various posts of folks accusing Brand X cams of being bad, or blaming poor preparation for issues, or saying make sure to do this or that prior to actually firing up for the first time, I begin to wonder and worry about things (again).

We recently got our BBC back from the machine shop and re-assembled it, taking great care to properly goop it up with a good quality assembly lube in all the right places as well as making sure everything was torqued properly and all bolt holes were retapped and the threads all clean and clear. Everything was oiled and we even went so far as to lube the bottom of the lifters in addition to the cam lobes.

When it comes time to actually fire this beast up for the first time, it will likely have sat assembled and sealed up for 6 months or so. With a good thick and resilient assembly lube and plenty of pre-lubing/pre-oiling, what else can one do? This is a hydraulic non-roller lifter motor with an aftermarket "Brand X" moderate street cam and heavier than stock springs. Our machine shop did the head work and assembled the valves and springs, but we re-assembled the motor. It's clean, it's tight and it's lubed...

Is there a good reference for the start-up process? How would YOU do it to have the utmost protection from potentially wiping a lobe and ruining our day?

getting worried...

 

[Rat Maker]

Baring any lack of quality on the part of "BrandX" cam the most fail proof method is (after all pre-lube)to use single springs for the customary 15-20minute break in. Without trying to sound cocky I've been involved to some degree in over a thousand engine builds since 1970. I personally have had 5 Cam failures & I know without doubt that 4 were of my making. Either improper lub, or to heavy of spring or engine not really ready for extended run for break in etc ... . and # 5 was likely my fault as I surely failed to pay enough attention to something. I've found VERY few T&D or auto machinists who blame th camshafts for their own failure it's 99% installer/break in. You can find out all you need and more through the Comp Cams website.

 

[wayner]

I have always barred and engine over (turn it over with a breaker bar and socket) while pre lubing at the same time prior to starting. I always felt this helped get the entire engine lubed.

 

[ss3964spd]

Dittoz (name Sir?),

From what I've read here, lobes generally go away due to excessive spring pressure, insufficient lubrication, or manufacturing defects.

Spring pressure: If overly concerned about this run a lighter set of springs for break in.

Manufacturing defects: Pull the cam and lifters and send them out to be tested for hardness. Mic the lifters and lifter bores for proper clearence.

Insufficient lubrication: Install lifters with the little oil hole in the bottom. Ensure proper pre-oil procedures just prior to firing the engine. Perform all adjustments, checks, and re-checks to ensure the engine fires immediately.

If incredibly concerned perform all three!

Good luck,

Dan

 

[dittoz]

Dan;

(Sorry, usually sign my posts...)

Truly, I wasn't THAT concerned over the prelube, but there seems to be a conspiracy (!) lately against cam manufacturers, engine builders, locust, or something and the more I read, the more I start to doubt myself.

I've done a fair amount of messin' around engine work in my 30 or so years of greasiness, but not to the degree my son and I are now. A complete teardown and rebuild doesn't scare me, but I want to make sure we won't be doing this again in the very near future.

So, a liberal (I HATE that word!) use of a quality assembly lube on all contact points, prelubing by both spinning a distributor shaft to the oil pump and incrementally turning the crank and oiling, we stand a reasonable chance of not uhurting anything.

It's a Comp 270H cam and the springs are new and are those recommended by Comp and are heavier than stock. I suppose we can remove the inner springs, but will it truly make a difference in reducing the potential for whacking a new cam?

-curt

 

[Randy Mosier]

Use the single type stock springs, adjust the rockers to a 1/4 turn past zero lash, pre-fill the carb float bowl with fuel to cut down on cranking time.

You can swap the springs and reset the rockers after the break-in period.

 

[ss3964spd]

Curt, - just bustin you chops with the name thing.

I dunno about you, but when was contemplating the cam swap in my 396 (408) I was almost paralyzed by analysis and fear of loosing a lobe - to the point I nearly bagged the whole idea.

But, the oil hole lifters seemed so incredibly logical to me that I decided to go for it.

What seems counter intuitive to me is loading on a bunch of cam/lifter paste lube and then spinning the assembly to adjust the lifters and do the pre-lube. I have to think the bulk of the stuff just gets squished out from between the lobe and lifter - leaving but a thin film.

As Randy said, use stock-ish springs, adjust, fill, and fire it. Consider adding a bottle of GM EOS - has certain additives that help.

Good luck...

Dan