cam break in - how soon after first start?

[miketyler]

Got my engine fired up yesterday for the first time since it was reassembled. (can I get a golf clap here?)

I know I have asked a lot of dumb questions over the last 12mos or so but it runs great. A couple of minor leaks but the erratic idle from that overpowered cam is gone and so is the harmonic balance wobble. It runs and idles very smooth. I appreciate the advice you all have offered.

We may have touched on this before but I couldnt find the thread so I'll ask again. How soon do I need to do this cam break-in thing? My tach wasnt indicating and I would like get that working before I attempt to time it and do the break-in.   

Engine then and now:

   

[Tom Quad]

The cam break in is when you first start the engine after install...20-30 min of run time, inital rpm of say 1800 till everything quiets down and then run at a steady rpm varying between 1500-2000rpm   mnaking sure the car doesn't get too hot [over 220] .  After that let car cool down for at least 1/2 hr, restart and run it some more up and down 1000 rpm - 2000 rpm

[Chryco Psycho]

I agree , the first 30 mins is critical , iif you shut down after wiping off the cam lube it may nothave adequate lube when re started & could fail immediatly

[miketyler]

I'm probably ok then; I dont think I have a total of more than 5min run time on it so far. For now, I wont worry with the tach thing, I can feel around for 1500-2000RPM and get this break-in thing out of the way.

[dodgetkboy78]

I usually monkey throttle it between 1500 and 3000, revving it higher for a sec. The reason is a constant no-load, on the rest of the engine isn't good for the other break in parts (IMO)
But, also, after about 10 minutes, I shut her off, check her over, and head out on the street.
The only cams I have had go flat are comp cams, and not until 30 or so thousand miles later.
Anyone else had this problem with comp cams?

[MEK-Dangerfield]

Anyone else had this problem with comp cams?

Chryco doesn't like them... so that's good enough for me(thumbs up smiley). Something about them being GM cams with a Mopar grind, but I could be off on that( shoulder shrug smiley).

 Mike

[Carlwalski]

I usually monkey throttle it between 1500 and 3000, revving it higher for a sec.
The reason is a constant no-load, on the rest of the engine isn't good for the other break in parts (IMO)

That's what I heard was a good idea too. Many, many different theorys and opinions on engine break inns though.
I guess they all work.

[Chryco Psycho]

good Luck Mike , the damage may already be done
 with the poorer quality lifters available now it is even more likely to wipe a cam , I lost 2 last year both in the initial 20 mins

[miketyler]

I am not too worried - most of the 5min of run time was at 1500+ rpm anyway. So how could you tell if you toasted one? metal particles in the oil or?

[Chryco Psycho]

generally it will take the lobe right off the cam & start missing with 1 valve not opening 

[miketyler]

Geezum! That seems pretty exterme! After I posted this I went to some cam manufacturers webpages. All their break-in procedures are similar. However new & reman engines go in cars every day and dont get the "proper" break-in. The customer gets the keys and is told, "take it easy for the first 500 miles, bring it back to us then for an oil change" and thats it.

Did you research to see if perhaps the cam and/or lifters were defective? Maybe a hardness test or something?   

[dodgetkboy78]

GM cams seem to go flat, and comp cams seem to go flat.
I have used Wolverine cams (cheap cheap cheap) and even the cheapo PAW and Summit cams, and they didn't go flat.
My comp cam lifters bleed down too.
Enough badmouthing now.......................

[Chryco Psycho]

kinda hard to test the hardness once it has worn through the hardened part
 most engines new or reman have some run time on    them & all newer engines use roller cams which do not need to be run in   

[miketyler]

I know nothing about the processes they use for hardening after the grind. I would assume all surfaces would be case hardened after grind and you could probably Rockwell test one of the journals to get a sampling of what the hardness at the lobes might have been before destruction.

I ran thru the break-in procedure yesterday and all seems to have went well. My engine was low time and already broke in. The only thing new components in the engine was the cam, lifters, timing set and oil pump. I will inspect the filter and oil carefully when I change it and keep my fingers crossed.     

[Chryco Psycho]

if it is running well you are ok