Ok, for those of you who dont know, I had a head gasket blew and decided to put in the LT4 hotcam and ported heads on my 95 Z which has 105,000 miles. Well I sunk over $2,500 into these upgrades; CAM, Headers,Port Job,PCM programmed, Labor, Plug wires, 160 thermo, Waterpump, Plug Wires, CAI. Worked on it for 4 weeks. And for what? A SPUN BEARING AFTER 5 MILES OF DRIVING!!!!!!! So, you will definatly spin bearings with the cam and head work. If you dont believe me, just search under "Spin Bearings" 9 out of 10 times it was after a cam job.

 

that sucks that u put all the $$ in just to have that happen...that's y when i blew my head gasket i just waited and save my $$$ and built my engine from the bottom up.....u can't build a nice house on top of an old rotting basement....

 

That is a pretty inaccurate statement.

 

Sorry to hear about your engine, but here is something I heard from a old timer who builds engines, and it makes sense. When you remove both heads and then add them back and retorque them, you can cause a shift in the main caps area that can lead to spun bearings. His suggestion is to remove only one head at a time, this way you keep a torqued load on the block, thus eliminating core shift as he called it. I find this feasible, but have no data, so if anyone out there can validate this I would like to hear from you. Sorry if this is hijacking your thread, but also wanted to pass this along although it is too late for now.

 

I don't agree with this either. I have had the hot cam in mine for about 6k now and haven't had any trouble.

 

I have put over 6,000 miles on since my heads and cam swap with no problems. I think the reason you see a lot of posts about problems is that people come here to vent their frustrations after something goes wrong. You hear lots about the bad, and little about the good.

 

I put a hotcam, heads, and longtubes on my 1997 Z28 with 90,000 miles on it, and I haven't spun a bearing with almost 110,000 miles on the clock now.......

 

I think you might be missing a key part of the equation here. Changing a cam and heads does not cause an engine to spin bearings. The odds are that when you blew the head gasket you damaged the bearing by either getting water in the oil or overheating the engine or getting a little water coolant in the combustion chamber causing detonation - another bearing killer. Another bearing killer is the crud that falls down into the pan and into the oil pickup when swapping heads. The only way to avoid that is by having the engine totally apart and cleaned.

 

Ditto, mines running great. Sorry about your spun bearing but it certainly doesnt happen with every cam install. Unfortunately, if you don't do it yourself you have no idea the quality of the work that was done during the install. Taking your time and doing things right, keeping the motor clean, not rushing things go a long way in a cam/head install. The most likely reason a bearing gets spun after a cam install seems to be debris getting into the oil pan and blocking up oil passages, or the pump.

 

I heard that before....

 

Your spun brg is probably due to the stock oil pan and the oil climbing the back of the pan under the extra accelleration and RPM's and uncovering the pickup.Or the brgs were damaged before the cam change.
Some people have the problem,some don't.
Don't agree with the head torque theory.It makes a small difference but not enough to blow the engine.It makes more difference when honing the cyls.

 

rofl spun a bearing because of a cam and head change ?

ha ha ha

 

 

say what you want, but I did the work myself and was extra carefull, the only thing I can relate to on this thread is the fact of the coolant getting to the bearings, I would bet my soul that mothing got in the oil! So those who want to waste money go ahead and change the cam without changing the bottom end,but, YOU WILL BE SORRY!!! And yes you can quote me!

 

I changed my heads a few years ago..and then I spun a bearing. (20K later)...due to a failed oil pump. LOL.. I would listen to any of the experience tech people here with many hours/years of experience..versus ..your..well..theory.