If I am going to try and swamp to a hotcam and I take apart the car, get the cam out and the front bearing looks worn out some. Are you basically guaranteed to spin some cam bearings if you put a new cam in instead of putting the original stock one back?

Also, if you are going to spin a cam bearing will it most likely occur right after you get the new cam in and are doing the break in (reving it to 2k for 20 minutes or so), or can it happen anytime down the road? I was wondering if after X miles its still running good, when is it safe to assume it won't spin? Assuming you are not reving over 6k, and the car is basically just bolt ons + cam.

 

Bro, that sux. Is the stock cam all worn/scratched?
was the car behaving strangely before the swap?
if it wasn't, then chances are that the severity of the problem would be dependent on the level of damage. A little wear will occur through thousands of miles. you would need to pull the motor if you want to repair the engine. at that point you should consider a full rebuild

 

I wouldn't chance it, throw on some 1.6RRs and let it be.

 

If it is worn, even if you do put back in the stock cam you are asking for trouble down the road. I would go ahead and start saving for a rebuild.

 

All front cam bearings are going to look worn. It's their nature. Normally, it is not cam bearings that spin, it's rod or mains from lack of oil pressure.

 

I would say go ahead with it man, no turning back now, like GreasyB said even with the stock one you may encounter problems, start saving up for a rebuild in the future, but keep going with what you're doing.

 

most of them i have seen look worn of the front beasring. don't know what you consider bad but i would install the cam

 

My front cam bearing looked worn 40k miles ago and 4 cam swaps ago and my motor is still going strong today.

 

There is no break-in required on hydraulic roller camshafts.

 

Great post.

Here was my front cam bearing at ~70K miles, it was gold and scratched all to pieces:



I was was wanting to to do a H&C but did not chance it. I pulled the motor for a full rebuild to the specs in my sig. The stock cammed stock motor ran fine with decent oil pressure. The stock cam had a few scratch marks on the front journal.

Bottom line is its a crap shoot to run a new cam on a worn bearing.

 

Cam bearings very rarely spin, like Shoebox said.

 

I installed a hotcam last winter and spun a few (rod?) bearings. But 5k later ive got an le3 355 ready to be put it
i say go for it... you spin a bearing you spin a bearing.

 

Not trying to be rude or anything, but then how come there is so much fuss about replacing the front cam bearing when doing a cam install?

BTW - This is hypothetical, this didn't happen to me but after researching the boards trying to decide what I want to do I got to thinking...

 

I've heard that too, and I've heard the opposite. People say you need to rev it to 2k immediately in order to get oil splashed on the new cam.

 

I've seen worse than that, and people still cammed it. Hope that makes you feel a little better. It's a crapshoot for sure like you said though.