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Breaking in this new cam in a 235 inline, mild performance cam. Says 20 min break-in, after 5 min. had to stop to cure oil leak then after about 12 min had to stop as she's getting to top of temp gage. Is this enough time???
Thanks
Jim
:p3:
 

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The real key was keeping the revs up right after startup, even if it was for only 5 minutes. More than likely you're OK, unless the valve springs have a lot more pressure than stock and/or the cam lobe profile is aggressive. Did you use a break-in lubricant or an oil with a high ZDDP content?

I'd go back and check valve lash after an hour or so of running. Clearances are probably a couple thousandths more than where you set them at initially, but if one or two are really high, I'd keep an eye on them.
 

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so far you only have 17 minutes. I would run it another 10 before I called it done. jmho
 

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IMO, with that old girl, you're fine, but it's it's always nice to run it through another heat cycle in the aftenoon with some friends before the beer lamp is lit. Makes for big smiles and good conversation.
 

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Run a box fan into the grill and keep a garden hose handy to keep the temp in check. If it starts getting hot, just spray a fine mist of water into the radiator. That should keep it cool.
 

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Simple addition.

Says 20 min break-in, after 5 min. had to stop to cure oil leak then after about 12 min had to stop as she's getting to top of temp gage. Is this enough time???
Stopping and starting the engine will not adversely affect the break-in IMO.

Due to circumstances, I have had to "accumulate" the 20 minute break-in time in starts and stops. It worked out fine.

In my understanding, the point of higher and varying engine speeds, during cam break-in, is to cause the oil spraying naturally off the rod journals to completely and thoroughly bathe the cam lobes with additive-laden motor oil.
 

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In my understanding, the point of higher and varying engine speeds, during cam break-in, is to cause the oil spraying naturally off the rod journals to completely and thoroughly bathe the cam lobes with additive-laden motor oil.
That is correct. These engines rely on splash to lube the cam. :tu
 

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Mechanical or hydraulic lifters? If hydraulic, if the lifters are new manufacture, keep a real close ear out for premature tapping. These new lifters have a checkerd history with respect to collapsing. If mechanical, I am with the others, probably fine but certainly won't hurt to do it for another 10 minutes, then drive it around a bit. Then change the oil.
 
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