Need advice!!! My 1980 4x4 pickup has, I believe a hybrid 20/22R - and a noisy rocker has recently gotten worse - it now sounds like a little fella with a machine gun hiding under the rocker cover. From 0.008 (Int) and 0.012 (Ex) I gapped down to 0.006/010 cold. This just made to worse, louder with a very real metal on metal ringing noise. So went back to 008/012. I haven't removed the cam/valve train from the head yet. But on closer inspection, the valve adjustment screws are all in good shape with no pitting and the little polished hourglass shape is plainly clear on the valve stem end. The cam followers and valve screws are all nicely lined up. The cam is discolored see pix attached. Oddly the TDC mark on the cam sprocket is about 1/2 a link off - not sure what that means. So all you 20/20R geeks - do I renew the lot, change the cam, what? I REALLY need the help!

Dot on sprocket not at 12 o'clock...

...even though Engine is TDC

Only one shiny lobe..

...other lobes look burnt

close up... Thoughts?

 

Timing marks are perfect. The dots are used for lining up the bright links on the chain upon assembly. There is a corresponding dot at the bottom of the lower chain sprocket (which you can't see with the timing cover installed). The bright links only line up with the dots on the sprockets once every few rotations of the engine so don't worry about them if they don't seem to line up now. When the crank is at TDC, the cam dowel pin should be precisely at the 12:00 position which yours is. So no worries there.

The darker areas on the cam lobes are normal. When the valve clearances are adjusted correctly, the rocker makes zero to barely any contact with the base circle of the cam. It only really contacts the lobes which should be shiny and smooth. The last picture appears to show some metal transfer or galling on the cam lobe. If that's not an illusion caused by the camera and reflections, that is definitely not good. No telling how much longer it will last. If no other damage exists around the engine a new cam and rocker assembly should fix it. Beware of any aftermarket "new" cams. They are made of soft metal and will flatten very quickly. Cams and rockers must be replaced as a set. They wear into each other. Cam replacement requires removing the head bolts and rocker assembly. Unfortunately this removes all the clamping force on the head gasket.

 

Thanks arlindsay1992 - as I suspected. And hopefully a new set will solve that pesky racket! You say "Beware of any aftermarket "new" cams. They are made of soft metal and will flatten very quickly." I've done a ton of research here and elsewhere and now the engnbldr.com is out of business there does not seem to be any type of consensus around who/where makes decent cams... any suggestions would be welcome.

 

I'd recommend 22RE Performance for cams. They can sell you a cleaned up OEM cam and rockers. I'd also consider LCE as a second choice but their cams are not made from factory cores. Stay away from basically anything you can find on RockAuto or your local parts store.

 

Yup - thanks - that's kinda where I am.. but these guys came up recently - Melling (Jackson, MI) - they get pretty good reviews from the Mopar crowd and they do have a 20/22R cam available - thoughts?

Here's their eBay listing through Quality Parts Plus...

Melling 22R rocker cam

 

Those rockers look like the early all iron ones.

I'd get them reground and polished if they are not too worn.

I don't know know where to source anything but aluminum ones.

 

Hey Millball - I suspected as much - would the cam be salvageable in the hands of a talented professional?

 

My DNJ cam went flat. I really didn’t want to use it in the first place, but not many options at the time. I ended removing a used one at a pick part yard. That one has been fine

 

Cams can indeed be reground. But, no ordinary machine shop can do it. There are outfits that do specialize in cam grinding work.

 

The cam maker that engnbldr used for their cams, now sells direct, since engnbldr closed up. I have seen him post in Facebook Toyota groups. So you can still get "engnbldr" cams if you want. If you're interested, I'll dig up his contact info from Facebook.
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