1978 280Z 2+2 Cylinder Head Removal

[MillerTime802]

Hey Guys:

Update on the ol Z. I took a month off for a vacation, family death, my business, holiday with the family, and some repairs on my daughters other stinking car, ha.

I installed the head and everything else, except the radiator, then went on a month sabbatical. Got back into the car this evening to start it. Didn't start, didn't hit a lick! Checked everything....wiring, timing, compression, spark, fuel, fuel pressure......no luck.

Took the valve cover off to start checking things again. Put the engine at TDC to verify timing and general installations.......huh, the cam lobes on cylinder #1 look funny and out of place at TDC.....I think I installed the cam 180 degrees out.

Checking info you guys sent me.....I discovered I had indeed installed the cam, relative to the cam chain and gear, 180 out. Removed the cam sprocket, turned the cam, reinstalled all.......and alas, she purrs like a kitten. Putting the radiator in tomorrow and will take her for a test spin.

I'll report in this weekend after I get the whole thing back together and take her out for a test spin around the block. Thanks for all your most excellent help. I absolutely could not have done thus without your help. Thank you, thank you. Brad.

Edited May 31, 2013 by MillerTime802

[240260280z]

Congrats! Nice report. Glad you won.

[LeonV]

Glad you got it done!

FWIW, you can't really install a cam 180deg out. It was your spark timing that was 180deg out (distributor), but you corrected it by phasing the cam. Either method works but I think turning the distributor (or rearranging the plug wires) is the easier route to take.

[MillerTime802]

@ Leon: Well, now that you posted your comment, I now know I had some easier options. Thus far, nothing went easy, so why not follow the hard road all the way home, haha. Actually, removing the cam chain sprocket and rotating the cam was very easy.

Took about 15 minutes with some help.....and since I hadn't removed the distributer during the head repair, I was freaked about pulling it and repositioning it. Now the plug wire idea.....that's classic easy.

Thank you for your review and comments.

[MillerTime802]

http://www.classiczcars.com/forums/members/millertime802-albums-daughters-1978-280zx-head-repair.html

Link to a few photos. I'll post some more of the completed job.

[Zed Head]

Removed the cam sprocket, turned the cam, reinstalled all....

This implies that it wasn't just distributor timing. You moved the valve opening events in relation to the crankshaft and pistons if what you wrote is what you did.

You probably got lucky with the P79 head on N42-block dished pistons, since the P79 has a higher dome in the combustion chamber, designed for flat-top pistons. If you had the N42 or N47 head you probably would have bent some valves. The factory L6 combinations are interference engines.

[siteunseen]

Crown & Coke but not one of the car? Come on, we're not all mechanics.

Your killing me with the stripped down KTM. A camera is my favorite tool.

Edited June 1, 2013 by siteunseen

[LeonV]

@ Leon: Well, now that you posted your comment, I now know I had some easier options. Thus far, nothing went easy, so why not follow the hard road all the way home, haha. Actually, removing the cam chain sprocket and rotating the cam was very easy.

Took about 15 minutes with some help.....and since I hadn't removed the distributer during the head repair, I was freaked about pulling it and repositioning it. Now the plug wire idea.....that's classic easy.

Thank you for your review and comments.

No worries, car looks good! Are you still planning on selling or will you be keeping it?

This implies that it wasn't just distributor timing. You moved the valve opening events in relation to the crankshaft and pistons if what you wrote is what you did.

You probably got lucky with the P79 head on N42-block dished pistons, since the P79 has a higher dome in the combustion chamber, designed for flat-top pistons. If you had the N42 or N47 head you probably would have bent some valves. The factory L6 combinations are interference engines.

Not following you here.

A cam cannot be 180* out. If a piston is at TDC, the cam will determine whether it's on the compression stroke or exhaust stroke. It's up to the distributor to spark the correct cylinder at the right time.

If the cam is "180* out" (exhaust stroke instead of compression) then all that needs to be done is to move the plug wires 3 spots over. The spark will then be phased correctly to the cam.

[Zed Head]

An incorrectly installed cam can be 180 degrees out. Just put it there then put chain on.

He wrote that he turned the cam shaft 180 degrees, with the sprocket removed. That's what I was replying to.

Edited June 1, 2013 by Zed Head

[MillerTime802]

See my link above to find some new photos of the car itself.

I added some photos of the car per my friend, siteunseen, comment. However, crown and coke helped this build go smoother. Now I can get back to my KTM.

@ Leon and Zed:

Before dis-assembly, I put the engine at 0/top dead center. On the cam, the lobes on cylinder #1 were in the horizontal but "upward position." When I re-installed the reconditioned head and re-assembled the cam gear to the cam, I had the cam lobes in piston #1 in the horizontal, but "downward" Position. Thus, indicating I needed to turn the cam 180 degrees to put it in the position it was in at dis-assembly. I think this is what Zed is referring to, and how I resolved the problem.

@ Leon: I think I could have just as easily resolved the issue by re-positioning the spark plug wires, or maybe by rotating the distributor, but I'v never done this before. I felt safer just re-positioning the cam to its dis-assembly position. And yes, we're still putting it up for sale. My daughter needs transportation and not necessarily a project car, as these classics usually are......not to mention, I want my man cave back, ha. She has $4,200 in the car...we hope to get her money back...what do you think?

Thank you for your comments, and there's always more than one way to "skin-a-cat."

Edited June 1, 2013 by MillerTime802

[siteunseen]

It's no wonder why your lucky daughter wants that car, it looks great and now runs great. Congratulations to you & her.

[LeonV]

@ Leon: I think I could have just as easily resolved the issue by re-positioning the spark plug wires, or maybe by rotating the distributor, but I'v never done this before. I felt safer just re-positioning the cam to its dis-assembly position. And yes, we're still putting it up for sale. My daughter needs transportation and not necessarily a project car, as these classics usually are......not to mention, I want my man cave back, ha. She has $4,200 in the car...we hope to get her money back...what do you think?

Thank you for your comments, and there's always more than one way to "skin-a-cat."

Good luck! 2+2 and automatic are not a popular combo but the interior is in great shape.