Zed Head

Seems like a lot of extra work to disassemble the half-shafts just to powdercoat them. The rubber boots and nylon bearing spacers might not handle the heat for a normal powdercoat material. "Suspension" covers a lot of parts. Coating choice really depends on why you're coating them, for rustproofing or looks or durability.

I'm pretty sure that I got a 1985 300ZX 5 speed for $20 because the PO couldn't get the drain plug out. I used the gears and back half as a 71C with a ZX 5 speed front/bellhousing swap, then tried to get the plug out of the left over front case using all kinds of crazy techniques; torch, solvents, breaker bars, etc. Ended up drilling a hole in it just to show it that I could use it if I really wanted to. It's available if somebody needs a 1985 300ZX front case/bellhousing.

Might also be possible that the shop that did your head enlarged some of the spray holes, screwing up the pressure distribution. One more thought...

Still thinking low flow out of the spray bar. Maybe a tube is coming loose and leaking, depriving some of the 12 holes of its oil? I'm not sure you would test besides maybe submerging in something like gasoline then holding it so that all 12 holes drain equally. Break it down in to sub-systems - oil pump, oil passages, head passage, cam towers, spray bar, etc. Even check that the the spray bar holes point and will spray/drip the correct way, on to the lobes. Just because fluid comes out doesn't mean it's getting where it needs to go. Somebody could have rebrazed your bar after it fell apart and got the holes pointed weird.

Seems reasonable. Or maybe they swelled after installation, after the machine work. Should be easy to see by eye. We need that picture. How many miles on the "new" head?

They don't look good. If you had lash set too tight what would happen is that the base circle would get shiny from the rubbing of the rocker arm (the base circle is where the gap or lash is and normally only feels the light pressure of the anti-rattle spring), and you would burn the valves that are set too tight because they wouldn't close completely and would over heat. As I understand things. It does look like you just have low volume of oil passing over the lobes, causing overheating. Lucky that you stopped quickly, the cam looks saveable. I might check the oil pump. The way the system is set up the head gets low flow, controlled via a small orifice in a plug in the head's oil passage, and most of the oil is routed to the crankshaft, where the forces are much higher. That's my guess - oil pump going bad. Or the orifice in the block itself is clogged. Actually, I'm going to change my guess to sludge in the spray bar. The spray bar is a piece of cake to remove. Maybe you already took it off. Just noticed that you blew air back in to the cam towers. Anyway, jumping to "remove head" seems premature.

Could be that you just need more RPM to get the oil volume up. Higher oil viscosity will result in lower volume (edit - actually that's a general statement. The pump likes high viscosity if it has loose clearances. There's probably an optimum viscosity for max flow). Start the engine with the valve cover off and see what happens. But a clogged oil restrictor in the block could cut flow also. The later FSM Lubrication chapters have great pictures and descriptions for the oil spray bar system. Try 1976 EL-2.

Is kijiji a Canadian word? Don't y'all have craigslist up there? Spring and summer are a good time to be looking. People clean out their garage and realize that it's time to keep that space open.

Do you have more information on the engine? There are so many different varieties of Chevy 350 out there. A picture of the engine might be nice also. Brakes are for slowing mass from speed, not really much to do with the power to get to that speed. Bad brakes are just bad brakes no matter what engine.

Maybe your original MC is not the stock 77 MC. Take a picture of the original M, that works, and post it.

That's weird. You're right, the ZX MC should need more push rod, not less. So your problem is backward. You can test if the return port is blocked just by blowing back through the return line. Kind of messy but might show something. You can see how the seal closes off the reservoir return as soon as the piston moves.

Maybe yer brain conflated Healey Z with New Zealand Z? See how easy that could be... (got to use an uncommon word, yay).

Curious - did your driveshaft yoke get damaged? I have an old 240Z shaft with a groove worn in it, myself.

Be careful straightening your dust seal (the external metal with the ding in it). Don't pry too hard against the aluminum or use a drift pin and a hammer to knock it back in to shape. You might consider just removing it, Nissan did on the ZX's. The double seal was overkill, probably, or caused rubbing problems when bent, like you might have.

I think so. A quick test is to compare the diameter of the new seal with the hole it needs to fit in to. Better check your propeller shaft (aka driveshaft) slip yoke for damage. The seals have a steel spring to maintain tension and when the rubber goes the steel wears a groove in the slip yoke.

Not much info there. Can't even tell if it runs. This Hagerty tool seems like a good start for guessing. https://www.hagerty.com/apps/valuationtools/1978-datsun-280z Are those Canadian dollars? http://www.xe.com/currencyconverter/convert/?From=CAD&To=USD

Seems too good to be true. Gotta be a catch somewhere. Maybe Rossiz can check it out. @rossiz https://www.hagerty.com/apps/valuationtools/1966-datsun-1600

Looks like they should. I have a 78 system sitting on an engine in the garage but I must have removed the bracket, it's not attached. But I did find it shown a parts diagram. Part #28, I believe. Looks like they only changed it once, in July 1975. http://www.carpartsmanual.com/datsun/Z-1969-1978/engine-280z/e-f-i/air-flow 14 hours - you've probably found it, fixed it, and moved on.

This Hybridz thread covers your problem, almost exactly. http://forums.hybridz.org/topic/113771-quaife-qdf7l-r200-missing-part/

There's a clip in a groove inside the diff. The clip drops in to the groove in the axle shafts, if everything's right. The clip stays in the diff when the axles are removed. Later, with the VLSD's in the 90's and maybe the opens too, Nissan put the clip on the shaft and chamfered the diff groove so that it would stay on the shaft. Sometimes people get them messed up if they're used to one style. Those look like 280ZX CV shafts (3x2 bolt pattern). So there must be an adapter on your wheel side. They still retain the clip in the diff though. but somebody has been mucking about back there so you'll probably have to take the axles out to be sure. you can buy the clips and insert them using a socket to drive them in until they hit the groove. Are you sure it's an LSD? People say you have to remove the cover to be 100% positive, but generally the "both wheels move the same way" test is a pretty good clue. Somebody might have dropped a VLSD in to your carrier also. I thought about it but it was too much work.

Took a couple pictures. Looks like the bottom of the spring has its own bolted on little piece. You can see half of the screw head holding it in the first picture.The top has a hole in the bellcrank, opposite where the plastic linkage ball snaps.on. It's all buried behind the distributor and lower than the distributor. Hard to get to. My car had a big spring attached to the valve cover and a piece of the throttle linkage, probably 'cause the PO couldn't get a replacement attached right.. They fixed it on the ZX and put the spring up top and easy to get to.

I have pondered the same but realized that at 10-13 psi system pressure the coolant's coming out no matter which side the valve is on.

Nissan calls them "Control Unit Checking Terminals". Shown on the big wiring diagram, by the ECU. Designed for some sort of test device. They just hang there, disconnected. Everybody wonders about them, eventually.

Actually, since the essential question (whcich lash pad?) doesn't consider the grind itself, or if it's stock or reground, I think he needs to take some measurements and probably do a trial or two. Lash pad thickness depends on more than just the cam. The procedure is described on pages 108-110 of Monroe's "How To Rebuild" book. No matter what you find out about the camshaft you'll still need to determine the right pad thickness for the head assembly by trial and measure.

One of the big problems with our automated world is that we forget where those automations came from - people. Why don't you send a message to a people and see what they say? Probably better than pissing a people off, as your first "new member" action, I'd guess Although, it looks like they might still use paper mail. People writing on paper, inserting in envelopes, applying stamps and waiting. Bizarre. You'll probably get your info in the mail. http://www.zonc.org/ Bottom of the page. There's also Facebook, and Twitter, and various other electronic alternatives. "ZONC PO Box #184 21001 San Ramon Valley Blvd. Suite A4 San Ramon, CA 94583"