Zed Head

The rocker arms generally follow the cam and the individual lobes. On the towers, the thought seems to be that if you can move things around to where the cam spins freely you're good. That's what I've seen described. Otherwise, you'd have to get a new set of cam towers when you bought a new cam.

Those are good points. The one about the cam turning freely and align-boring is one of those areas where Nissan and the rest of the world seem to disagree. Nissan would have you replace the whole head, but there's much written about tapping the cam towers when installing to get them adjusted so the cam will turn freely. People swap towers all the time apparently.

It should be fine. The oil flow is controlled by a restrictor in the head gasket, not the passages in the block or head or towers, and the size is the same for spray bar and internally oiled cams. And the oil pumps are the same also, old versus new. So the same quantity of oil is flowing to the cam towers. From there, oil flow and pressure is controlled by either the holes in the spray bar, or the holes in the camshaft. But they both start with the same amount.

Tapatalk is associated with your phone, It's an app. It's not necessary. What happens when you click "no" to the question?

Yeah, it is interesting, The guy that makes them has been around for quite a while and seems to know what he's doing. But Nissan used to make a one-piece arm, with a chrome-plated rubbing pad, and they switched to the brazed on pad made of more wear-resistant material. So even if the loads are handled fine you have to wonder about longevity.

Could spend more - http://www.zccjdm.com/catalog.php/azcarbum/pd2120660

Not to pick on your builder but he could mock things up with your old gasket, or no gasket and some math, and some clay or soldering wire, and actually measure the clearance. Most of us get disturbed because we don't have the experience or the tools but this should not be a big deal. If he came to you and said "the new pistons are only .015" from the head and that's a problem" that would make sense since there are general guidelines/thoughts on that clearance. But the consternation over .007", right off the bat, seems odd. Either you're not getting the complete message or he's getting disturbed over something he shouldn't be. Anyway, it's all part of the game.

Once you get started you'll find that it's really not too hard to get the wires right. Even with a complete diagram, you should always check your wires with a meter or test light, just to be sure. It's a bad feeling to watch smoke rising or see sparks when you decided to just take a chance and trust somebody else's write-up or memory..

Disturbing. Their web catalog of services says that they work on 81-83 L28's, which all have a pop-up of ~.020". He shouldn't have been surprised and should have compared to the old pistons right away. Not really clear what the problem is. If the new ITM's are just a hair off the old, what's to be right pissed off about?

That is ever so much clearer. Kidding. Kind of. Seriously, you need numbers. Really though, your engine builder should be familiar with this and know how to deal with it if he's experienced with the engines. Nissan pistons are all essentially the same except for flat-top versus dished. Did he say it was a problem or just mention it in passing?

If there is nothing special about the sealing edges of the water passages in the gasket, I would just drill the newer gasket to match the older. Clamp the gasket between two blocks of wood. It's a common method to prevent tearing or chipping of sensitive material. Or carve the holes out with an exacto knife. Not as hard as it seems, if there's no metal layer.

Which is old and which is ITM? You don't really say which is which. There's much written about L28's and piston pop-up of about .022" but I can't find much on L24's. BRAAP measured a bunch of L28's with flat-tops. Post #19. http://forums.hybridz.org/topic/58127-best-way-to-achieve-piston-to-head-clearance/

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