Zed Head

Those look like Hulk hands. Don't get angry! I had a thought on your copper spray question - better check the head for warpage. Copper spray = head gasket or head change = potential overheating = potential warpage. Although, since you're playing with the N47 head on the L24 block, it may not be relevant. Your title is "Rebuild" but it seems like you might be leaning toward "Performance build".

They do look good. Did they send the ZPaste along with the rockers? Wonder if they've always done that or if the recent cam destruction cases have made an impact. Maybe we should thank Leon and madkaw for their sacrifices, along with yours, re DPLLC.

Yep, the toothpaste is out of the tube now... On wiring diagrams - Saridout's wiring diagram links in his past messages don't work anymore so I sent him a message. He's moved them to a new spot. I put the links at the end of his previous messages so that no one has to come here to get them.

New links - http://sridout.com/storage/datsun/70circuit_COLORFINAL.pdf http://sridout.com/storage/datsun/72circuit_COLOR4.pdf

New link - http://sridout.com/storage/datsun/76circuit_COLOR.pdf Thanks to saridout. He's out there somewhere.

The recommendation about the crossmember is good, but the later model Z's used rubber bushings on the member/body mounting points. So it won't be rigid like an early 240Z would be. False sense of security. Still, you could tack in a brace or two, or drill a few holes to mount some strategic braces.

Come Oooonnnnnn! You can't be serious!!!!!! Cars!!!! Let's not discuss this at all.

Nice pictures. I can see the factory hone marks in the cylinders but also the classic rust line of an engine that's been sitting (my old one has that). I see that you have a chain tensioner block installed. Like you haven't decided yet how far to tear it down.

Is it not described in the FSM? Nissan did a good job of showing how to tear down their transmissions. MT chapter, choose something like 1986 300ZX. http://www.nicoclub.com/archives/nissan-300zx-factory-service-manuals.html

And circle back to Post #89. Trust but verify.

I see. It came that way, previous damage. I started in the middle of the pictures. Looks like your damper was going bad also. Do you have specs. on the engine. CR, valve lift, final displacement, etc.? I saw the general stuff but no numbers. The valve relief in those pistons has to lower CR. Just wondering. Looks like he's running 0.54 mm (0.021") "pop-up" on the pistons also. There was just an interesting thread on that a few days ago. Thanks for posting.

I'm still betting that some of the rocker arm refinishes are done by people there who don't know what they're doing. If your batch gets the right guy, awesome, if you get the wrong guy, hell. It's a simple looking job that takes a lot of care to do right. Set up for mistakes.

Serious looking pistons. Must be planning some high valve lift. Post 70 and 80 say stock stroke. Do you know why he had to massage the oil pan? Just curious.

http://www.classiczcars.com/topic/50944-want-slightly-louder-exhaust-without-changing-much/

The L28 will definitely give more power. 17% more displacement. If you're worried about CR, you could get a P79 head, then you'll be at the factory's 8.8 CR. Make sure the SU's can flow enough air to feed the L28 if you go that route. I'm not an SU guy so don't know what people do when they go with a bigger engine.

Not sure. Many people have done what you're doing though. Some say the box is fine without the floors, some say it's all wiggly and twisty. There's probably a best method out there somewhere. What I'm saying is that locking in a misalignment with new welded-in parts, then bending the box's new metal and welds to get the suspension aligned, could cause warps and bends in unwanted places. My guess is that the best way to do it is in parallel. At the same time. Weld the parts in while controlling alignment. Just bringing up a different perspective.

I think that this might be backward. Don't forget that these are not "framed" cars. They are big sheet metal boxes, kind of like an old lunch pail. AKA monocoque or unibody. Best to use the welding to hold or create the shape, not bend the welding after it's done.

"They" say that a good modification for more power is a more free-flowing exhaust system, from the manifold back. The whole thing will drop down and drag out from under a jacked-up car, Then you can hang it from the rafters in your garage. You might consider that option. Bigger pipes, larger diameter anti-resonator in the middle and a free-flowing muffler. More power and better sound. Three nuts and some hanger bolts (hooks and rubber donuts if you do it right) and you're swapped.

The stock gaskets are at 1.25 mm thickness, I believe ( I've actually measured my crushed factory fire-ring in addition to the general view). So at zero deck, about .049". Which is about where Monroe (the unofficial authority) recommends piston to head clearance. So, an 020" pop-up puts a person at .029". Which is tight. It's an interesting discussion, because most of Monroe's work is on the Z engines, not the ZX. The ZX, F54 flat-top, seems to be where the .020" (or .018" to be more exact) seems to come in to play.

All good. Still interested in how it turns out. Need to keep tabs on the best way to rebuild. You, madkaw, and siteunseen all have some work going on. Good stuff.

How much piston pop-up? Are those ITM pistons? Hope it all sticks together this time.

I think we're on the same page, as is redzed. His builder has a comfort zone, as he should. Good info though on the ITM L24 pistons. They are, apparently, .020-030" taller than stock Nissan pistons. Whether it matters or not. That's what I got out of the thread.

Let's take a breather and get back on track. The guy doing the work on this engine apparently wanted a zero-deck. So he felt like machining the pistons was the way to go. Sounds like he was working off specs. and not off what "could be". He probably would have been okay with leaving the 020" pop-up.

No biggy, just a smally on your comment to madkaw, Especially since you edited close to the time he asked. Anyway. The ZX F54 flat-top piston engines all seem to have a pop-up of about .020". But there doesn't seem to be a lot out there about the early L24 flat-top engines. Maybe they're zero pop-up (I'd use "deck" but it's hard to keep the +/- signs correct). But they both use a similar gasket thickness so your .020" pop-up probably was fine. The 030" that Diseazd had might have been in that worry zone, but even then, some guys like to run a really tight squish distance. But that's with forged parts to minimize stretch at high RPM. To top it off, somebody (madkaw maybe?) said that Rebello thinks the ZX P79 cylinder head "squish/quench" design was poor. So, overall, it seems that keeping the pistons from hitting the head might be the main concern. From there, you can get in to forged parts, and RPM, and all kinds of details. Shaving the pistons for insurance is probably the way to go. Too bad ITM is producing out-of-spec. product.

Thanks for being honest. You were being misleading in your post above, to madkaw, though. Not good.