Well I got the new stock cam installed & broken in and the engine seems to be running a lot better overall. It has a MUCH smoother idle, it's much snappier at lower RPMs, and doesn't seem any less powerful at higher RPMs. The exhaust at freeway speeds has quieted down some as well. I'm not sure if the 270 cam was a bad grind, prematurely worn out, or just a bad match for my engine, but *so far* I am happy to have a stocker back in.

When I pulled the 270 cam, I inspected the rockers, adjustment screws, lobes, and journals. Everything still looks brand new except the leading side of the cam lobes are all polished. I think that's normal for cam wear, but correct me if I'm wrong. All lobes showed this wear on the leading side. There weren't any gouges or ridges on any of the machined surfaces. Timing chain and guides still look good too.

EB I am curious if the 270 cam was ground from the same castings as the stock spec Melling. The casting looked identical and I could only find one stamping that was not the same between the two. I took a picture to show the lobes and also the stamped numbers that were different.

Here are the stamped numbers that were different (bottom is EB270 cam "G 16", top is Melling stock cam "K 5".


Here is the lobe wear after 30k miles on the EB cam (left) versus a new Melling (right) Like I said, I think this is pretty normal cam wear.


Here are the rocker and adjuster screw surfaces. They looked polished, but no scrapes or gouges


I dropped the truck off at the smog shop when I was finished, but they wont get it on the dyno/smog machine until tomorrow morning. As soon as I get the results I will post up the before and afters.

It took 4 hrs to swap a cam, adjust the valves, adjust the timing, and break it in. Not too bad I don't think, do you? For what it's worth, even though I've done this before, I found Arbitrary Notion's 4x4wire tech article to be a very useful reference. Here's a link: http://4x4wire.com/toyota/tech/camshaft/

Okay, I give. I have gotten 30k out of your cam without being disastified until now and you certainly don't owe me anything. I would buy from you again in a heartbeat!



We'll see tomorrow after it goes on the dyno. The only thing not stock on the engine now is the oversized valves on the RV head. If it still doesn't pass emissions, we can almost be certain it's just a failed ancillary and NOT the camshaft.

>>>*Melling doesn't make camshafts of course. They buy them from that company, CWC (which is a mirror image of CMC.)

You will find about 90% of all camshafts sold, including nearly 100% of domestics and the vast majority of imports sold by the aftermarket will carry that logo.

American made stuff. We seldom use them anymore except as backup, ours are either TSU which will have just numbers, no letters, or TAE blanks now, everything we have is special ground except for the stock ones.

Yes, wear appears very minimal, of course the rocker pad drags on these so they will shine in...*EB

I got word back from the smog shop and the stock cam did not entirely fix it. There was an improvement though. Now everything passes except HCs. There is still a problem somewhere, likely unrelated to the camshaft.

I do not have the numbers yet because I just spoke to the shop over the phone. When I get all my paperwork back I will report on how things changed between the stock and 270 cams.

Just an FYI, but MagnaFlow/Carsound makes some universal fit OBD-II compliant catalytic converters. These are excellent at reducing HCs.

http://www.car-sound.com/02product/universal/430.asp

At around $200, they aren't cheap, although you can find them on ebay for a bit less, but they make a substantial difference over even a new non-OBD-II cat.

-Jeff

That's funny because that's exactly what I have on it. I put it on about a year ago when my old cat started to rattle.

I think the smog shop is replacing it yet again <img src="/forums/images/graemlins/frown.gif" alt="" />

*EDIT*

PROBLEM SOLVED

I just got off the phone with the smog shop. They replaced the cat and now the emissions pass with flying colors. He said the old cat was completedly burned out on the inside. I wonder what caused that since I've only had it on for about a year? I wonder if whatever caused the previous cat to start rattling/come apart is what caused this one to come apart as well.

Anyway, can't wait to go pick up my truck! <img src="/forums/images/graemlins/smile.gif" alt="" />

If you have been running rich since the magnaflow cat went on, the excess gas is what probably burnt it out. The new cat may not have fixed your high HC's, only masked them to get by the smog check. There is a good chance you are still running rich problem which is what led to the premature failure of your cat. How old are the O2 sensors? If they are the originals, or have more than 80k on them, it is time to change them. When OBDI sensors get old, they get lazy and tend to cause the engine to run rich, commonly seen in a loss in mpg's.

I agree, the cat may be masking the problem.

The O2 is a Bosch replacement that's about four years old (there is only one, in the manifold). The shop said they checked it and it was good, but I'm not sure what they did to check it. I haven't shown any codes for O2. Not sure if that means it's okay or not.

I've heard the Bosch o2's do not stick far enough into the exhaust to give an accurate reading, i'm sure alot of people on here agree with me, get a OEM o2 sensor.

I'd go one step further: the Bosch O2 sensors are crap, and fail easily; I burned through a bunch when I was running the stock EFI. The OEM sensors are much more rugged and seem to last significantly longer. YMMV, but that's been my experience.