Zed Head

I usually ask a bunch of questions to learn from, then go with the opinion of the expert. In your case, if you choose and things go wrong, the builder can say "told you so". If you go with his choice and things go wrong, he ll be more likely to make it right. Good luck.

What do you mean by "quality"? Just curious. I would rather use an ugly gasket on that does the job best, than a shiny smooth one that has problems. Just saying, once it's buried under the head they all look the same. Head gasket discussions are always interesting. Who is your engine builder? Is he experienced with these engines or just engines in general? p.s. It's champing, not chomping.

Here's some interesting stuff. Follow the supercession path and you end up at - 11044-E3102 (I think). I'm guessing the P3... numbers are E88, maybe. Courtesy Nissan shows potential - http://www.courtesyparts.com/gasket-cyl-p-239863.html Of course, there's an assumption that only the gasket changed, not the head. And with Nissan, you might still get a different part when you order it. By the way, the Stone gasket seems to be one of the cheaper gaskets out on the internet. If you trust RockAuto and Beck Arnley, there's a $62 HG on the Rockauto site, with the Beck Arnley history behind it. They seem to know what they're doing. Also, on "graphite" material. I think that's meaningless. True graphite would be useless as a gasket material. I think people call anything that looks like it's fibrous, and is black, "graphite". I posted a link to Oliver's ZSpecialties site. Personally, I would go with the opinion of somebody who's rebuilt a lot of engines, if you can get it from them. They're the ones who get complained to when the HG fails. Maybe Eiji would be worth a call, or Rebello.

The brown is from the other pickup coil. Just insulate the end so it doesn't generate random sparks. Edit - forgot to say, you'll lose the 6 degrees of vacuum advance from the water temperature switch activation. That's another wire that will need to be insulated, I think it's powered with the key. What all of the wires and the extra pickup coil do is described in the Engine Electrical chapter. I did something similar a while ago. Wired a 1978 plug on to the 1976 connection terminal strip so that so that I could use a 1978 module. It's doable. Locate red and green, insulate and set aside the brown, determine which one is hot with the key on (it's connected to coil positive), and figure out which is coil negative (pretty sure it's blue). The colors at the coil and distributor are the same as at the module.

You never really said why you want to do this. Are you missing the stock unit or do you think it's not working right? Here's the link from EuroDat's work with the GM HEI module. Same idea, 4 connections and ground the metal base. http://www.classiczcars.com/topic/49588-fitting-a-hei-module-in-transistor-ignition-unit-1977-280z/ You'll probably have some extra wires down there from the other magnetic pickup coil. And you'll need to figure out which wire is power and which is to coil negative. Engine Electrical chapter should help. Or just use a meter.

It's not dead, it just links to the originators web page. Looks like he moved some things. It used to be there. Regardless, everybody knows that wiring diagrams are in the FSM. The wires at the ignition module are red and green though. Stick your head under the passenger dash and look. With Steve J's post you have everything you need. Don't forget to make good contact between the metal back of the E12-80 module and ground. That's where the current through the coil ends up.

He made a joke, that was on target. It was funny. I laughed. Not even close to bullying. Your reaction is waaaaaaay overblown. You got so focused on the perceived insult, that wasn't even there, that you didn't address any of the suggestions that were made. Did you roll the car after putting it on the ground? When did you do the work? Are the springs properly seated? Then internet is not meant for communication, it's meant for transferring large data files.

Here's a 76 wiring diagram - http://www.classiczcars.com/topic/33820-free-full-color-wiring-diagram-for-1976-280z/ Here's a link to a picture of the module connection - You might have to guess on red and green, it looks like the wires are attached to the distributor. If you get it backward the engine will still run but the timing will jump around. http://www.oreillyauto.com/site/c/detail/BWD0/CBE503/02801.oap?year=1981&make=Nissan&model=280ZX&vi=1209349&ck=Search_ignition+module_02801_1209349_-1&keyword=ignition+module&pt=02801&ppt=C0334

That makes the most sense, aside from new Paraut arms, I think. It's a shame though that Delta had a short period of time where they were grinding the surfaces off-axis, or non-parallel. There are a few threads around from the past, where people showed that was the case, real measurements. Had to send them back. They really damaged their reputation with that. Maybe had a new guy running the equipment or didn't maintain it. Anyway, it they're doing it right now, that looks like the way to go.

When you say "new rockers" what do you mean? Brand-wise. I think that might be part of the problem, The options are getting more limited. There seem to be cheap ITM brand or more expensive Paraut. http://www.stockwiseauto.com/product_info.php/cPath/1109_1277/products_id/1977610/Make/Nissan/Model/280Z http://www.ebay.com/itm/Rocker-Arm-NISSAN-280Z-280ZX-200SX-260Z-240Z-510-610-710-720-810-MAXIMA/310974615448?_trksid=p2047675.c100011.m1850&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D28808%26meid%3Dead19cd0317c4ffc8973541fc719bf9b%26pid%3D100011%26rk%3D1%26rkt%3D1%26sd%3D130906675945

Glad you're staying cool about the whole thing. Back to the big picture - I wonder if DPLLC isn't just buying rebuilt heads from the stores and reselling them. The two week lead time is really two weeks to get them from OReilly's. Might explain all of the packing material and surface rust on your last "freshly" rebuilt head. Let me know when you're sick of the whole thing and I'll stop. I can't resist exposing these kinds of people.

Yes, it seems like slightly worn Nissan parts might be better than new aftermarket parts. Probably the only thing better is brand new Nissan original parts. They also seem to be implying that the refinishing operation on the rocker arms can take off too much metal. Looks like still no guaranteed path to success on a cam swap.

Only adding this link to fill out the story. I feel like we should start a crowd-funding campaign to support rossiz's illumination of DPLLC's competency. Anyway, looks like there is another option for cylinder heads. Wonder where they come from. Actually a little cheaper then DP. http://www.oreillyauto.com/site/c/search/Cylinder+Head/02257/C0332.oap?make=Nissan&vi=1209237&model=280Z&year=1976 Who wants to be the lab rat? Post #163 of this thread from another forum is interesting also, re rocker arms and cams - http://forums.hybridz.org/topic/112117-new-cam-and-rockers-odd-looking-at-500-miles/page-9#entry1133995

Seems like this would be the match.

It could probably be drilled. Sandwich it between two blocks of wood. The early blocks and heads apparently had dead zones in the coolant passages that didn't flow much coolant. This lead to hot spots. The later design is probably just meant to keep cooling flowing at the rate that the pump could pump it and well-distributed. If your pump does 10 gallons per minute and you have passages for 50, you won't get good flow distribution. So, you could even consider improving the flow distribution in the head. But you'll have to make educated guesses. Too much knowledge to be comfortable now.

For clarity...

Comparing the Stone HG to the E31 diagram it looks like there are no issues. The gasket makers are just putting extra holes in everything. If there are two passages you get flow if not, you get a little round spot on the head. Edit - actually, what's interesting is that even the HG designed for the head has blocked passages in to the head. The bottom row has tiny holes in the gasket and some are blocked. The HG is the flow controller, not the passages. So you really need to compare an old E31 HG to a new HG to see what's what. I don't think the passages in to the head matter much.

The N42 head looks similar though.

Here's a good thread from the past that I was able to refind. Were it mine I might just punch a new hole where the E31 needs it, if the gasket material in the area is sufficient. Looks like you'll just be missing two center holes. Size might be different though. Also made a composite picture so you can see the differences. I'm assuming that the guy who put the drawings together used the proper heads and knew what he was doing. http://forums.hybridz.org/topic/115160-l6-cooling-system-diagrams/

Not really clear when the suspension was assembled. Maybe you didn't get the spring properly seated in it's perch. There's a spot for the ends of the spring coils to sit in.

Any chance you could put the gasket on the head and see what holes match?

I remember laughing inside when a friend showed me his new Toyota T(u)RD truck. This new L(i)MP one is on the same level. Maybe it's a subliminal marketing gimmick, designed to catch the eye.

You picked up a new L6 engine in Seattle?

Stepping back and looking at your whole saga, it seems apparent that the DPLLC guy doesn't know what he's doing. Or the mechanic he's using doesn't. Or both. Or he has a collection of heads in a warehouse somewhere and he just went and pulled another with the same problem as the first one. Maybe all rebuilt to the wrong specs. Regardless, it would probably help somebody out in the future to let DPLLC know that the second head's lash pads were off also. He either doesn't know or doesn't care. Maybe he's getting screwed by another guy who's rebuilding his heads. Still, he might be able to fix the problem for some future buyer.

Here's an option not mentioned often. Oliver seems to know his stuff. The page might be dated though. 2012. http://www.datsunstore.com/advanced_search_result.php?keywords=head+gasket&x=0&y=0