this may be a crazy question, but here goes. Ill be breaking in a new cam probably this week and was wondering if cold weather would play a role in the success of it. Its supposed to be in the high 30s and low 40s this week.does outside temp matter?

 

temprature will not be a factor.do you have a thermostat installed? just run it at 2500 for 20 minutes to half an hour.i've never had a problem doing like this.maybe a real exotic system requires somethig else so we'll wait till a bullet builder checks in.

 

The critical things are:
1.) You need to have a good smear of Cam Lube (the special grease made just for this purpose) on each lobe, each cam bearing surface, and the bottoms of all the lifters.

2.) The engine needs to get good oil pressure and circulation within a couple seconds of starting up.

Beyond that doesn't matter too much. If the cam survives the first ten seconds, you're probably fine. Yes, it's a good idea to run the engine at 2000 rpm or so, at least until it's fully warmed up before shutting it down.

I'm not sure how much real "break in" there is to a cam. The surfaces of the lobes and the undersides of the lifters are hardened and ground to a fairly high polish. As long as they have sufficient lubrication, there isn't supposed to be much significant wear to the surfaces over many years and miles. Any tiny bumps or imperfections are going to get polished down in the first thousand times the engine spins over; that is, the first 30 seconds. Beyond that, either they're happy together forever, or the thin hardened surface wears through and the cam lobe wipes out in the next 100 revolutions.

It's a very different situation from rings and cylinder walls, which do actually wear into each other.

 

Make sure you use an oil with zinc additive like Rotella T for diesel or a off-road racing oil. I wiped out a Comp cam and I was told the modern oils don't have zinc like the pre-roller motors oils did. Very important!!!!

 

is this a new or used motor? used motors or motors with alot of miles break in is critical this also helps seat the cam to old bearings,At one point or another we all have made the common mistake of putting new cams in old motors,and a week or two later you start loosing oil pressure when your setting at a red light. break in is critical !! if it has 100,000 + I strongly suggest new cam bearings..cbeer68 is right use an oil with zinc additive.

 

A good zinc oil(valvoline racing oil,pennzoil gt racing oil,rotella t oil)zinc additive,a good moly paste on all lobes and bottoms of lifters(crane cam moly paste is very good)coolant system up to level,timing light hooked up before start up,i like to keep a box fan blowing onto motor as well,thats up to the individual,when dropping distributor make sure it has plenty of advance for quick start up,pump carb so its primed and ready for quick start,start,get the revs up to 2500 and run for 20 minutes.check timing for not too retarded situation.A good way to see if motor is too retarded,is to turn off lights and look at headers.If they are glowing,its a good bet its too retarded.Advance it up.Keep eyes on coolant level and temperature and you should be good to go.Now if this is a roller cam,than all this methodology does not pertain.

 

Nothing could be further from the truth! Proper break-in is an absolute must for a hydraulic flat tappet camshaft! It is true that modern hydraulic roller cams don't require a break in, but flat tappet cams most certainly do. The lifters and the cam lobes do "wear in" and the initial heat cycle helps to ensure the proper metallurgical properties are obtained. It is also extremely critical that your oil have the proper additives in it for break in or else you can go through the process for nothing. If proper break in is not followed the cam will not heat cycle properly and the lobes will be left "soft" and will wear out in no time. Check with any of the big name cam manufacturers, they all have a break in procedure.

 

im running a comp cam and using their red oil on lobes and lifters with a pint of GM EOS m ixed in. Will also be adding a bottle of zdpplus on future oil changes. the motor is used but runs strong and burns no oil. The cam is mild . this all started with a simple oil pan and timing cover oil leak fix.

 

I understand how that goes. If I have to remove a part I hate to replace it with something stock if there is a better option. Now sometimes money doesn't allow, but hey I've got nothing but time.