[leecorrell]

The cam chewed itself up in less than 100 miles in my 86 Fiero 2.8 V6. I can't explain this one, and it really upsets me. This was a bone stock rebuild, stock replacement cam and lifters with factory valve springs. This is the first one I didn't rebuild myself, I purchased a rebuilt engine, trying to save time and get the car back on the road quick. I did double check just about everything on it just to make sure it was done right and all seemed good to me. I used Lucas cam/assembly lube, STP oil treatment with ZDDP, and I used some old spec SAE30 oil from before they removed the zinc. The factory valve springs in these engines is a single spring with an inner sheild, so there was no inner spring to remove for cam break-in. Besides that, the top end on these Fiero specific MPFI engines is a pain in the hiney to dissasemble and reassemble. To get the valve covers off you have to remove the upper plenum, then the fuel rail and injectors, then the middle plenum, then you can get to the valve covers!

What the heck could I have done to avoid this cam failure? The last (and only other) cam I lost was in the 455 in my '67 Lemans back in 2003. I had pretty high spring pressure on that one with the new springs and I didn't know at the time to remove the inner springs for break-in. So that one had some explanation, but I can't explain this one.

What do I do different when I get around to re-doing this one to make sure I don't loose the cam again?

[rohrt]

How long did it sit before you started it up?

[Mr. P-Body]

Stock replacement cam? Who is the vendor? Part no.? Same question for lifters.

Jim

[leecorrell]

After I tore it down, inspected everything and re-assembled, I had it installed and fired up within about 2-3 days. When I started the cam break-in, the timing was off far enough that the headers were glowing red within about 5 minutes, so I shut it down. Advanced the timing a little and fired it back up and completed the 20 minute break-in varying rpm between 2000 and 3000.

[leecorrell]

No idea on who made the cam and lifters since I purchased this engine pre-rebuilt.

[Rugratman]

Just one or two lobes or all of them?

[Donovan]

makes a person start thinking about doing an engine swap...

[leecorrell]

Well, now I have to be honest. I hadn't actually seen the cam when I ASSUMED it had went bad and posted this topic. I was basing my assumption on my previous experience with a flat cam.

I finally pulled the top end off last night and I can't find any obvious damage to the cam. I'm feeling kind-a lost on this one right now. The engine was making what I orginally thought was a knocking sound. I also could see glitter in the oil on the dipstick. Since it is easy to pull the pan on these Fiero's, I went in there first. I found a good coating of metal powder in the bottom of the oil pan. I checked all the rod and main bearings and they all looked good. Then I took a magnet to the metal powder in the oil pan and found it to be magnetic and I assumed the cam had to be bad.

If it isn't the rods or mains and it isn't the cam and lifters, then what in the heck can put that kind of metal into the oil and make a loud knock? Cam and distributor gear look good! About the only thing left inside the engine that is magnetic is the the timing chain and gears which were new and maybe a busted piston ring?

[Mr. P-Body]

We've seen SOME 2.8s and 3.1 with cam bearing issues in the past. The valve guides will make a clatter if they're wobbly.

Is it possible the metal was in there when it was "rebuilt"? I ask because I've seen "wrecking yard rebuilds" before...

Jim