new camshaft break in

[littlekeeley]

so i have a new camshaft, and every search i run on google has told me a formula of 20 minutes at 2000rpms (varying from 2k to 3k interchanging)

 

my old man had new camshafts put in his 911 a while back, and his mechanic said it wouldnt be broken in until 1000 miles, then he could really drive it.

 

i dont like the idea of flattening lobes, and was hoping i could get some help on this idea?

[HRH]

What motor do you have that this new cam is in?

[Lozer]

break in is about 1k just dont keep it at the same rpm's. ive built alot of porsche motors in my time and only once have i ever seen a flatend lobe (we know the guy was hammering the shit out of the car) So as long as your dont beat on it for a bit you should be ok.

[littlekeeley]

break in is about 1k just dont keep it at the same rpm's. ive built alot of porsche motors in my time and only once have i ever seen a flatend lobe (we know the guy was hammering the shit out of the car) So as long as your dont beat on it for a bit you should be ok.

 

see my dad repeated that verbatim.

my confusion is, why does one extremely common method across the interwebs tell me to keep it at a certain rev for x amount of time,

while people that i seem to trust a bit more and have more to risk (monetarily), tell me thats one of the worst things to do.

keep in mind, i dont know a whole lot - so maybe my lack of knowledge/experience is keeping me from understanding, but it just seems like the two methods of thought are contradictory.

 

oh yeah, its on an L16 with a racing spec cam. i know thats generic, but for what its worth - its huge.

[HRH]

For an L16, just be gentle for awhile, then let 'er rip. Never had a problem with any flattened lobes on L motors. Now big block Chevys need to soft spring the cam for a while or they will tear it up, but that's a domestic crap factory for you. (Pauses...waits for domestic v8 love backlash...) :D

 

Be sure you have the rocker arm geometry correct, with the correct lash pads for the gigantic cam. Don't be trying to use stock lash pads. That will tear up a cam. I'm sure you know this.

Edited January 17, 2009 by HRH

[datzenmike]

Make sure you have lots of good oil in it. Using Nissan rockers and not some knock off Chinese crap? If using a spray bar is it adjusted properly? Do you have a hi-vol oil pump for lots of supply. If yes fire it up and forget about it. You've done all you can to ensure lubrication. A cam does not work harder if you step on the gas harder. It only works the valves at different speeds... that's it. All I would do is keep the max revs down for a few hundred miles, but full throttle all you want. Enjoy. Oh.. check the lash regularly until you are sure there is no change in the settings.

[littlekeeley]

you guys rock, thanks!

 

the geometry is right, and am using proper sized lash pads. all is well, but i wouldnt mind looking into a possible oil pump upgrade, like you mentioned mike. i havent poked around yet since i haff no moneyz. but it sounds like a great idea!

[datzenmike]

The hi-vol has the same pressure (but you could shim it for more) but pushes more oil per turn. I've measured the internal rotors and they are 14% longer than regular stock ones.

 

Here's an example: My old L20B has over 300,000km (180,000 miles). the hot idle oil pressure was 17 lbs. With NO other change, I put a used one in and it jumped to 29 lbs. At speed it's around 55-60 lb. And this is an old used hi-vol pump!!!

 

Go to a wrecking yard and pull one from any:

 

'86.5-'88 D-21 Hardbody with the Z24i motor.

240 sx with KA24E or DE motor

There are others but hard to find now. If getting new order for any RWD KA motor.

[ggzilla]

Call the cam manufacturer and ask them. Traditionally, you put lots of cam lube on the lobes, and on first start, run at 2000 RPM (never idle it) for 20 minutes. Failure to do this may result in flattened lobes. Now that's traditional for most brands, engines and cams. I've never heard of any other recommendation.

 

Again, since you are hearing two different stories, ask the expert -- the company that made the camshaft. Didn't it come with a piece of paper with installation notes?

[littlekeeley]

so this may be a newb question, but im a newb.

 

why is letting it idle, such a bad thing? its a slower rotation making me think less heat... right? i mean, if its rotating fast, there would be more heat, and the lobes would wear easier right?

 

ehh questions questions i know

[datzenmike]

Higher oil pressure?

[ggzilla]

To answer that question, ask the camshaft vendor. I don't know the reason why. But have seen plenty of cams totally worn out at 15k to 30k miles.

[littlekeeley]

Higher oil pressure?

 

lol and theres the feeling of "d'oh" i was expecting.

[datsunfish]

Just out of curiosity,since you said the cam is huge,are you aware of the max lift for stock springs? Its 460,which is not a huge cam and older sss racing setups came with a cam around 430 or 420 I believe. Do not install a cam above 460 without spring mods. Also you can only go to 170 on the lash pads in stock retainers,which is what a regrind 460 would require. Just saying you need to make sure you have what you need. With a regrind or new cam you need new or reconditioned rockers too. You cant simply drop in a new cam unless you are just using a l20 cam which is not much of an improvement.

[ppeters914]

I believe there's also some controversy about what oil to use, especially during the break-in period due to the lack of some ingredient. Sorry, I don't remember, but I'm sure others here know what I'm talking about and can fill in the details.

[datzenmike]

The ingredient is likely ZDDP. It's a zink additive that the makers are slowly reducing the amount of in their formulas because it ruins the new catalytic converters on new cars. You can still but it separately in a can, look on the additive shelves, but be sure you know what you want. The expression 'snake oil' isn't a joke.

 

Diesel oil still has, or did have 'normal' levels of ZDDP. You could change to diesel oil for the break in and switch back. Some suggest switching to synthetic and then back but that stuff is so slippery that I doubt it will break in.

[bonvo]

the only one ive heard is the run it at xxxx rpm for xxx minutes

 

of topic but i have to ask what happened to the ae86 in your avatar that poor car:(

[ggzilla]

For new rings, they used to say to use a straight, non-detergent oil. I don't know if this is still recommended, but it wasn't for camshaft.

 

For cam, you can put cam lube on the lobes while assembling.

[Mark_Z28]

Go to an auto parts store and get some cam break in lube, its usually a thick black type stuff that sticks to the cam lobes long enough to get the oil to it. Any non roller cam would require a similar break in, import or domestic. The standard advice of varying the revs from 2-3K over 20 minutes will break it in fine, but as advised follow the cam makers instructions for break in if they include instructions.

[DISLEXICDIME]

with my 480/280 cam and slodats 490/290 cam we had to turn the idol up to 1200 rpm to keep the proper amount of oil on the cam at idol :)

[datzenmike]

Get the Hi Vol pump.

[DISLEXICDIME]

they bolth have them

[Wharf Rat]

I think the first twenty minutes are critical, run at high idle for for max oil presure then your all set. A good assembly lube like STP or a moly base grease is the most important. Also if the cam has high lift you want check for spring clearance. Good springs are a must. With no clash or bottoming out at full open. shims are included and specs sheet. Roll engine over by hand and use feeler gauges to make sure you are safe! Make sure the spring coils don't touch each other at full open or it could be messy the first time you rev her hard.

[stilltwisted]

the cam breakin lube i use has molibdem diesulfide as it mane lube {or moly},, and i keep the idle high enugh to get good oil presure ,, but not so high as to cause excess heat to the upper end,,also use kendel gtone nondetergent strait 40wt oil only for break in ,,then dump the oil ,,change filter at the same time ,,

 

 

as for bigblockchevy , heavy valve train , high seat presure , odd push rod angles , 10 year older design , more care should be taken during breakin period ,,i do like them ,,my 454 runs great ,,,,just my 2cents

[rusty510]

you can also use diesel oil to break in new internals. just go buy some diesel 10-30 or whatever weight you prefer. its the same stuff, but it still have the additives they took out of regular oil for emissions.