Camshaft Install Questions

[75sierraclassic]

Well I found out this weekend that my camshaft is going out in the truck. Its a comp cams extreme energy 262 with only about 35,000 miles on it. I measured the lift on the #1 exhaust valve and only saw .120" lift when it should be around .460". I'm a little ticked that it only lasted that long. Have any of you had problems with these cams?
My main question is, how much work is it to install. In order to have enough room in front of the engine to put a cam in while the motor is still in the truck I know you at least have to pull the radiator, but do you have to take of the tranny cooler, condensor, or core support? How much of the front do you have to take off to make room?
I don't have a garage and would have to do it in my apartment parking lot, so I am contemplating if it is even possible. Anyone in the Kansas City area want to take on a weekend project? J/K. I appreciate the input.

[blazer2007]

Is a fair size job,u have to drop oil pan a bit to get timing cover off, plus harmonic off, water pump, intake off ,dist. out valve covers off, loosen valve train then you can take cam out.Then do it again after you set valves and retime engine

[swb85]

I lost an exhaust lobe on a comp cam after just 12k miles. I swapped cams with the motor in the truck, but the 73-80 core supports are a bit different than 81-87.....yours should be easier. You'll have to remove the radiator, move the a/c condenser out of the way if you have one (you can leave it connected, just carefully move it out of the way), and any coolers mounted up front need to be moved. It's a pretty simple job, just time consuming.

[75sierraclassic]

Originally Posted by blazer2007

Is a fair size job,u have to drop oil pan a bit to get timing cover off, plus harmonic off, water pump, intake off ,dist. out valve covers off, loosen valve train then you can take cam out.Then do it again after you set valves and retime engine

What do you mean do it again after setting valves and timing?

[blazer2007]

put it all back together,

[Slonaker]

I did a cam swap on my old engine with the engine in the truck. I removed the radiator and my trans cooler. I left the condensor in the truck, but unbolted the hold downs that hold the hard lines to the fender to get it to be as flexible as possible. I then lifted the condensor up the bare minimum to swap the cam, and tied it there with a piece of string.

You also have to cut the core support since it has a vertical brace in the middle. I cut it at the very bottom, as low as possible so it wouldn't be noticeable, then bent it up out of the way. I didn't have a welder back then, so when I was done, I cut a patch from a piece of sheetmetal, and used it and 4 self drilling sheetmetal screws to attach it back together. I shot the patch and the screws with some flat black, and it blended right in. You would never know it was cut.

There is a good article by board member swervin about doing a cam swap on 73-87.com. Follow it, and you will do fine.

http://www.73-87.com/7387garage/drivetrain/cam.htm

As far as the cam wearing out, maybe this info will help:

http://www.cranecams.com/?show=newsLetters&no=260

It talks about there being less zinc in oil than there used to be, and it causing problems with cams. They suggest using Shell Rotella oil and Chevy EOS during break-in, but I have been reading stuff lately that says Rotella and the other diesel oils are reducing zinc as well. I just know what I read, and I don't know how much of it is true. Unfortunately, I read it all AFTER I did the break-in on my new crate engine.

Slonaker

[75sierraclassic]

Well I finally got the cam replaced in my truck. It turned out to be a pretty big project. It took all of two solid days to get it replaced. The core support for my 75 did not get in the way of removing the cam, but I did end up having to disconnect the condensor to be able to reposition it enough to get the cam out. The only lobe that was ruined was the #1 exhaust lobe. the rest of the cam and lifters looked to be in pristine condition. It seems that if break in or oil constituents where the cause, the rest of the cam would have looked worse. Seemed to be just on of those things.

[85 c-10]

Have you had it running again yet? You'll want to break in the cam and lifters for about 20 min. before you start hammering on it. I always use a good diesel oil, like Rotella T. There have been numerous articles written about using newer oil on flat tappet cams. Q-state Racing is good, and there are a lot of additives you can get from GM to help with break in, and general everyday use.

Josh

[75sierraclassic]

Oh yes it has been running! I broke it in per comp cams instructions, 30 min at 2000 rpm. I used a good diesel oil and applied the supplied moly lube. My dad is a diesel mechanic and he can get good oil. The brand is Detroit Diesel. I didn't use the recommended comp cams break in oil (not the moly lube, but an engine oil they have developed to used during break in).
I live in Kansas City (moved out here a year ago for a job) and am originally from Evansville, IN. Since I have an appartment and no friends with garages, I drove it home to replace it. It made it 400 miles on 7 cylinders going to IN, and it had no problems on the 400 miles coming back home. Counting the 200 dollars in gas to drive home and back it cost me about $500 after cam and various other parts.