Camshaft question

[theczechone]

HI,

I am slowly going through a 240 that I bought. I did my valves the other day and noticed a few things that I had a question about,

 

1) My cam has a orange stripe painted between the third and fourth lobe. A friend of mine suggested that it is a performance cam, as that is the way they used to mark them.

I wanted to ask if this is true, and also, how do I find out what grind it is and what to set the valve clearance at? (car has been sitting up for years, right now I am just trying to get it to run right, haven't really heard a good

idle yet.)

 

2) If you look in the picture below, a part of the spray bar has broken off on the far left. I took the picture prior to this discovery, so if you look close you can even see the piece sticking up about an inch away from rotating

parts. Anyway, is there a way to reattach this piece or can I do away with the spray bar all together?? what are my options? Lobes 11, and 12 look very dry compared to the others, so i'd think the spray bar is necessary, but

let me know.

 

Thanks

 

[BluDestiny]

You should get a new spray bar, I believe someone was making billet repro's of them.

 

As for the cam, if it has a "japan" stamp on it it is an L series cam, not necessarily stock (could have been swapped). Paint could mean a regrind?

[rossman]

That cam is toast. #6 cam lobes have been starved for oil. It doesn't matter what it is because you need to get a new cam or have it re-ground.

Edited March 20, 2012 by rossman

[NewZed]

http://atlanticz.ca/zclub/techtips/cam/index.htm

 

If you find that it's a stock cam, you can download the FSM and look in Engine Mechanical for the valve lash specs.

 

Your cam lobes will most likely die if you don't fix the spray bar.

[theczechone]

rossman , when you say that the cam is toast, what do you mean by that? Is the engine not going to run properly, at all, or what are you implying by toast? I see that the lobes have not been oiled as needed, at the same time

however I don't see why the engine would not run with this cam. Either way I will put on a new spray bar, if I can find one.

[rossman]

I didn't say the engine would not run. The worn lobes are most likely going to destroy themselves prematurely. Since this is a performance zcar site I assume you would want to do the job right. If that is the case then you should replace the cam, rockers and associated parts.

[theczechone]

Well, I have just purchased this car, and I'm just trying to get it to be in somewhat running and driving condition. The engine numbers do not match so I will build another engine to drop in. This engine is just supposed to get me around until than. I agree with everything you said. The car has sat for a couple of years and I'm sure that every seal in that head leaks, but it would be nice to take it around a block.

I wanted to know if this is a performance cam or not as I understand that the valve clearance settings are different. From what it seems, it's just a regrind but I will inspect the cam for the Japan or any other stamp tomorrow.

Thank you guys

[HowlerMonkey]

If this is just a placeholder engine and the last few lobes still have a surface that is smooth to the touch, I would add the missing oiler spray bar and run it to see what happens while keeping an eye and ear on those lobes.

Edited March 20, 2012 by HowlerMonkey

[theczechone]

^ that's what I was thinking. Because I don't have internal cam oiling, I should be able to run the engine w/o the valve cover and w/o making too much mess, is that correct? Just want to check that all the lobes are getting oiled.

[Leon]

^ that's what I was thinking. Because I don't have internal cam oiling, I should be able to run the engine w/o the valve cover and w/o making too much mess, is that correct? Just want to check that all the lobes are getting oiled.

You NEED a new spray bar if you want that engine to run ok much longer! Do not try to repair the one you have if that's what you're thinking.

Edited March 20, 2012 by Leon

[NewZed]

Couldn't the OP just get an internally oiled cam, block the spray bar holes and live happily ever after? Less chance of ground up cam debris in the oil.

 

Seems odd, but the L24 and the L28 used the same cam, according to the atlanticz info. I think that the internal oiling came around in late 77 with the N47 head.

Edited March 20, 2012 by NewZed

[rossman]

Sounds about right. My late 76 280 came with an externally oiled cam.

 

My current setup is both internally and externally oiled with a high volume oil pump.

 

Another option is to find a good used head and cam combo and swap it out.

Edited March 20, 2012 by rossman

[theczechone]

Leon, where could I source a NEW spray bar, courtesy parts doesn't list one online ... and google search has turned up nothing

 

NewZed, I'm not sure that a new cam is possible on my current budget. If I got a whole new cam wouldn't I'd have to replace the lash pads and springs and such? I actually have a coltcams C.542.s extra cam that came with my 77 3.1L stroker (I miss that car), and I was going to use it when I build another stroker motor. Wouldn't it be a waste installing this cam in this tired motor? If i did install it what all would need to be replaced in the valve train.

 

Again thanks guys

Edited March 20, 2012 by theczechone

[NewZed]

Get a used one. That might be a point of discussion though, a mismatch between cam and rocker arms. Not sure, but I don't think the rocker arms are as sensitive as the lash pads. I think that I've read accounts of swapping cam only, with no issues. But, your whole thread is mainly about peace of mind anyway.

 

In the end, you're probably looking at about the same cost and effort to fix the spray bar and reinstall it on a cam that might already be damaged and dying, versus installing a used cam that might not like the rocker arms, and die.

 

Those spray bars are difficult to find, but a local wrecking yard might have one. They're used up to late 77 on all of the L6s, 240 through 280.

 

Edit - here's what will probably happen - you'll find an old Z car or engine, take the valve cover off and there will either be a usable spray bar or a usable internally oiled cam. That's when you'll have to decide.

Edited March 20, 2012 by NewZed

[Leon]

You could find a used one in the classifieds or the small Z-parts businesses (Z-barn, zparts, Z-Specialties, etc.). A quick search says you can get a brand new, billet spray bar from Larry Hassler at 626-358-2885.

 

From: http://forums.hybridz.org/index.php/topic/102501-spray-bar-mia/

[Gollum]

I'd just go to the local junkyard, find the best L cam I can find via OEM grind specs, pull the cam, towers, pads, and bar (if internally oiled) and call it a day. Swapping the cam + pads + towers shouldn't be more than a 3 hour job for the lazy garage mechanic with beer in hand. Finish it before 5 hours though if you tend to down your beers. Finishing in less than 2 hours could result to too little beerage and thus a dangerous next couple of hours as you start "fixing" other things on your way through the beers you bought. Don't go down that road. Have you seen the cars stuck on jackstands on this site? Exhibit A...

 

 

In all seriousness, changing cams on these engines is easy as pie and donors are EVERYWHERE. I can go to the junkyard once every other week and see at least two NEW datsun L6 donors that have come in. They're THAT common, around here at least. My issue is that my local yard charges too much... Scrap steel/aluminum prices are really driving the prices out of the range that used parts should go for.

Edited March 22, 2012 by Gollum

[BlueStag]

HI,

 

 

2) If you look in the picture below, a part of the spray bar has broken off on the far left. I took the picture prior to this discovery, so if you look close you can even see the piece sticking up about an inch away from rotating parts.

 

 

Funny. I had the cover off the other day, and noticed that the exact same piece was bent away from the cams slightly and was a little loose. The lobes looked ok to me. I wonder if my spray bar is about to fall to bits?

[rossman]

Funny. I had the cover off the other day, and noticed that the exact same piece was bent away from the cams slightly and was a little loose. The lobes looked ok to me. I wonder if my spray bar is about to fall to bits?

 

Yes, replace it. I believe I have a good used one if you or anybody else wants it. Another option is to get one from Larry (phone number above). His is solid and will never break.

[Perfect240z]

You can turn the motor on with the valve cover off with a oil bar and not with a internally oiled cam/cam towers?

Edited March 22, 2012 by Alex731

[theghosttanker]

Wow there is all sorts of misinformation going on here.....where to start?

I've seen factory stock cams with red and also white stripes marking them like yours. The lash pads are not what you need to worry about when you change cams; you need to make sure the wipe areas on the rocker arms are reground to eliminate the ridges worn in at the edges of the wipe pattern. Lash pads are only changed if you need thicker or thinner ones to keep the cam wipe pattern centered on the rocker arms when the valve lash is correctly set. The procedure for checking wipe patterns, lash pad thickness, and lash pads must be done properly every time you change cams, rockers, or lash pads. It's a tedious but necessary procedure; anyone who says changing cams on a z is quick and easy is NOT doing it right.

Replace your spray bar. Measure the damaged lobes on your cam with calipers and see if the largest diameters (taken from the base to the tip of the lobe) are different from the undamaged ones. If there's no big differences, I would recommend you keep running it as-is with the new spray bar. Since the engine is gonna get replaced soon anyhow, it's hard to justify the work and expense of replacing that cam unless you absolutely have to.