Cam breakin Procedure

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ValiantMike

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I just buttoned up my 318. Installed new cam, heads, lifters, springs, retainers, headers, etc.. I fired it up for about 10 seconds then shut it down. What I need to know is, what is the procedure to run it for breakin, and how long? Anything special, or just run it? I'm using proper type oil, additives, coatings, etc.. Thanks Mike
 
well if there are no leaks - run for 20-25 minutes @ ±2000rpm with a few blips of the throttle during - change oil and filter - go have fun.
 
There has been some info on the latest oils out and the possible damage to cams on break in. Be sure to not use "energy conserving" oils. If you do a search I think there is a post that also suggests using a GM oil additive for cam break in. Just a thought.
Cheers
 
ValiantMike said:
I just buttoned up my 318. Installed new cam, heads, lifters, springs, retainers, headers, etc.. I fired it up for about 10 seconds then shut it down. What I need to know is, what is the procedure to run it for breakin, and how long? Anything special, or just run it? I'm using proper type oil, additives, coatings, etc.. Thanks Mike
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Unfortunately, by running it for 10 seconds, you have wiped all cam lube off the lobes without running it long enough to break the cam in. That's a big no-no. You should have kept it running for 20 minutes. You can take your chances and break it in for 20 minutes now and hope for the best. Or pull the intake and re-lube the lobes as best you can.
 
If you have a cam break-in additive in the oil I would go ahead and run it in
like 388Dart says and just make sure it doesn't get too hot. I put a big fan in front of the radiator and had no problems.
 
Yea Lee, I probably shouldn't of started it until I was ready to run it for 20 minutes. I have Shell Rotella T oil in it now, and after breakin I'm putting in Valvoline VR1 oil. I did extensive research and both of these oils were the ones most knowledgeable people recommended to use, because they have zinc and other additives in them. CompCam also recommends the Rotella T. I'll do breakin tomorrow, but I'll pump up oil pressure before starting, like I did today. Thanks for help. Mike
 
Mike, it's not oil pressure that oils the cam lobes. It's actually windage..the oil slung off the crank and rods spraying up. So there are a few things that have to happen right for things to go smoothly. Firdst, the carb should be primed by filling the bowls thru the vent tubes(holley/carter types) or passages (edelbrock type). about 1/2 a soda can fills the bowl enough to get ot running. The fuel tank needs to have more than 1 gallon in it too if it's a mechanical pump...so the pump has an easy time drawing up the fuel. Next, the oil system should be primed with a shaft. You dont need to rotate the engine to get it to the rockers...you want it to hold presssure for a short time, so the oil gets squished out of the rods and dripped on the crank. Next, the distribuotr has to be in the right spot. It doesnt have to be perfectly timed, but it has to be between 0 and 10° before TDC on compression stroke. The cooling system should be about 3/4 full. Just enough to cover the top row of cooling fins, but dont fill to the top. All this is done so when the key is turned, the enigne starts right away, the rpms can be raised with the idle speed screw to at least 1800rpm (I like 2300) and it will keep running and flinging that oil up. If you have to shut it off because the coolant is pouring out onti the fan and going everywhere, or the fuel in the tank runs out, or the engine catches but the oil pressure takes a second or two to come up, then another second or two to bleed thru and fling up... Then the cam has been turning at least 10 full revolutions against the full valve spring load with no oil getting to it. If you used the starter to crank it to get fuel pressure or oil pressure, you make it worse because you are just removing the little layer of protection the cam manufacturer gives you in that lube. On the oils, anything rated "SM" regardless of type or brand (rotella, Valvoline Racing, etc) all are drastically lower in the stuff flat tappets need. The best thing to do now, is add a can of Hughes or Comp Cams or similar additive for flat tappets every time the oil is changed. I currently use Valvoline Racing straight 30 and have had no issues, but my dwindling cases are SL rated, not SM. I'm looking into Joe Gibbs Racing Oils for the future.
 
One thought that no one has touched upon, and for good reason as none of us like to have to go through this, but that is to use a set of break-in springs for initial fire-up. I did this at the behest of my machinist (who has seen far too many cams wiped out recently, even by people that know what they're doing I might add) on the 340 that I installed in my '74 Duster last fall. It was a serious pain to swap springs on the driver's side with the venerable A Body booster & master cylinder in the way of cylinders 3, 5, & 7, but it ensured no failures. I too used the Rotella T (although I have read recently that even the Rotella T is not exempt from the zinc removal as of this year) as added insurance. Just for reference, I used a Comp XE274H and corresponding springs in this engine. Not having to deal with or worry about this sure makes a roller appealing, despite the additional cost. Just my $.02 as well.
 
I have a Hughes roller cam. I have buttoned everything up, used the Shell Rotella T, and have primed with a drill. Question is, if the engine sits for a few months do I have to remove the intake and relube?
 
Roller cams need no break-in. That's one of the benefits of the roller desighn.
 
one of my engine guys says to use crane/comp break in lube for about 1000-1200 miles and then you don't need any additive after that. does that sound right?
 
I'm not concerned with detergent packages at this point. I want the cam to run for the life of the engine. These vehicles get very short oil change intervals, and the oil control in terms of the seals, guides, rings, and ring finishes are vastly improved. So I know it's non detergent. I choose that over not having the right additives to keep the wear parts intact.
 
Red, no, that'snot right. You must keep adding the additive with each oil change, as it will be carried out with the old oil.
 
Sorry, I forgot the assembly changes that you should make...lol. The lifter rotation needs to be checked. In my case, I either use a flex hone, or a ball burnisher to properly size the lifter holes. Then I install the cam with no lube, and the lifters w/WD40 on the sides. Mark each lifter and the bore with a black permanent marker, then rotate the cam in the block with the timing set installed. You should see the balckmarks seperate on every lifter, about 8-10° every time the lifter goes up and down on the lobe. If it doesnt, you can mix and match or if you must, hone or remove the burrs that might be stopping it. Then, when the heads are assembled, if you run a double spring, leave the inners out. Replace them after the cam has been broken in and the break in oil/filter dropped.
Sorry I left that out before...lol.
 
so i guess the best thing to do is to do what your cam makers says to do for breakin correct??
 
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