When Did They Switch to the Internally Oiled Cam?

[Captain Obvious]

When did they switch to the internally oiled cam and ditch the oil spray bar? I would like to know if my 280 is internal or spray bar, and I would rather not pull the valve cover right now.

Is there a head number or build date?

And yes, I know... There's no way to know what any previous owner did.

[zKars]

No need to pull the valve cover. Open the oil cap and take a look for the spray bar. And for confirmation, get the cam lobe thats right there pointing up and look for a hole in tip of the lobe face.

[Bonzi Lon]

I remember reading somewhere it was either in 77 or 78, still needs to be confirmed.

When my engine was rebuilt in 1980, they told me the new bigger cam would be 'internally oiled & do away with the spray bar'. At the time, it was over my head, so I just nodded.

Bonzi Lon

[Captain Obvious]

Open the oil cap

So simple it's genius! Thanks guys! :classic:

[mgood]

Here is a picture of mine form a 76 - 280Z.

[Captain Obvious]

I pulled the oil cap on my 77 as suggested above, and I do not have a spray bar.

My lobe wasn't in a position where I could confirm an oil hole for internally oiled, but I gotta assume that it's internally oiled. I would have already wiped lobes if it wasn't.

mgood, Thanks for the pic. So assuming both cars are stock, then they changed somewhere between 76 and 77.

I've been on a spray bar kick lately, and the small tube on yours that sprays the two rearmost lobes looks like it's angled inwards toward the cam. If that's the case, then the bar probably isn't sealing well against the rear journal. You might want to give it a good going over to make sure everything is OK. I recently completely reconstructed mine on my 74 because it was falling apart.

[jerz]

My UK (right hand drive) parts book advises that the spray bar was fitted up to a manufacture date of February 1977, but no reason to suggest other markets were different.

[Zed Head]

No need to pull the valve cover. Open the oil cap and take a look for the spray bar. And for confirmation, get the cam lobe thats right there pointing up and look for a hole in tip of the lobe face.

Great suggestion. I think the hole is on the bottom side of the lobe though, not the tip. Probably the leading face, to get the oil on the lobe before it starts working. For future oil fill hole peekers...

[Milenko2121]

my '77 was built in february and my cam is internally oiled.

[Jeff G 78]

The standard answer is that the cam became internally oiled with the introduction of the N47 head in the '77 model year, but this isn't completely true. I happen to have a N47 head that came from Nissan with a spray bar and a solid cam. I'm not 100% sure the head was ever part of a production Z though. I bought the head about 10 years ago from a guy who claimed it was owned by a Z race team and the head was taken off a production L28 when the car was new and had been on a shelf ever since 1977. I couldn't find any evidence to dispute the seller's claims. It looked like a brand new head with no wear pattern on the rockers or cam, and it didn't even show signs of having been run. It was also obvious that it had never been cleaned or bead blasted. I replaced the valve seals and have been running it ever since.

[Captain Obvious]

I haven't determined the build month of my 77, and I don't know what previous owners did to it. I have no reason to believe that it's not stock, but who knows?

One of the reasons I was asking about all this is because I've got low oil pressure on my 77, and I know that a leaking spray bar could be one of the reasons for it, especially after seeing just how leaky my rickety original spray bar was on my 74.

Anyway, unless a previous owner put an internally oiled cam into my spray bar head and didn't cap off the journal holes, that's not my problem. Haven't looked into it yet. C'mon spring!

[Pomorza]

Captain obvious,

When you say you have low oil pressure is that at the gauge (in car) or did you varify that using a mechanical gauge? Z gauges are notorious for not being all that accurate. I've seen Z car oil gauges read 0 when they had 35 psi. As for the build date it should be on the drivers side info plate. I should read something like 1/76 (mine) or something.

On a random note, my Z was built 1/76 and has an internally oiled cam. Not sure if its the original head (as I'm not sure of anything on the car) but it is an N47 head.

Jan

Edited January 16, 2012 by Pomorza