Well was out tuning a carb that I just finished rebuilding, and went to sratt it after setting the float levels. When as it was cranking I heard this terrible squeak from my back cylinder area right under the valve cover. So I turned the key and just hit the starter button, and there is a steady squeak from undef the valve cover on the very back cylinder, just a quick squeak, kind of a 1,2,3,4,5,squeak,1,2,3 if you get what I mean. It sounded topside just the valve cover, so I pulled the cover, and saw that the oiler tube is completely unbolted(bolt was still attached) on one side, and appears to be cracked. It was dark so I'm not sure yet but I'm suspecting either the cam itself, or a cam bearing. Valves don't usually squeak. If any of you datsun guys have a better idea that would be great. If I do swap cams, could I use a later self oiling cam with my stock journals, and eliminate the oiler tube? If I use a later head I can keep carbs right? I suppose I might need a different exhaust manifold if I use a later head. I would most like to have be it just a cam swap or something else simple to do, any good input on the matter? Any advice when dealing with the head or cams on these cars?

It's all there if you search, but sounds like another victim of a bad oiler tube. Get some light on there and get some pics. Yes you can swap to an internal oiled cam-recommended in my book anyway. Lot's of options but you need to study up on these engines.

You should fill out your signature so we aren't guessing of your set-up now.

If you're really lucky, your cam survived and you can just fix the spray bar, or get another one. If you need to change cams, and get a used one, get the rocker arms also, and keep each rocker arm with the cam lobe that it was riding on. The cams are notorious for destroying themselves if things aren't just right after they're been moved around. Sometimes they still self-destruct.

Testing

Will a self oiling cam, say out of a ZX just bolt in my head be self oiling without any extra work? That is with the matching rockers of course. And what year did the exhaust ports change?

Skim through this for the info you're asking about, The Datsun Workshop Cylinder Head page

Welll a friend with a lot more experience told me to try puting some grease on thd cam lobe I suspect and see if the noise goes away. And it did. So I think for now I need to fix the oiling issue and see if the cam makes it. The cam lobe looked the same as the others and it was never even actually ran while making the noise, so I hope it'll be OK. I think the oiling tube is toast and saw this on ebay, any opinions?Datsun 240Z 260z 280z Camshaft Oil Spray Bar | eBay

Would the stock bar be putting out a good spray under cranking? When cranking it looked as though there almost mothing coming out, and I'm wondering if its blocked, the soldering looks damaged and it was very bent from becoming unbolted.

Captain Obvious had the same problem and built his own spray bar (link below). I notice that the eBay bar is straight and sets the squirt holes farther back from the lobes. It seems like Nissan put a lot of effort in to getting the bar closer to the lobes than a straight bar does. Nissan could have made a straight bar for cheaper than their multi-piece bar, I would guess, but didn't.

http://www.classiczcars.com/forums/engine-drivetrain-s30/44750-camshaft-oil-spray-bar-redesign-rebuild.html

The spray bar can have a build-up of sludge internally. When you remove it. check the holes in it to see if they're plugged. A couple of mine were. I soaked it in laquer thinner for 24 hrs. & used compressed air to clean it out. I did have to repeat the procedure a few times until I was satisfied. New cereal box gaskets & now the oilers squirt instead of drool. It had the rear tube warp but it seemes fairly secure for now & the bar is now oiling all twelve.

Mark In Portland