Zed Head

How about a blender and a bucket of lemons? AK260'z Jenolite uses lactic acid. https://www.classiczcars.com/forums/topic/64766-citric-acid-and-rust/?do=findComment&comment=611145 https://jenolite.com/pdf/rust-converter-msds.pdf

I've wondered what happens to the valve angles. Their center lines moved with the warpage but aren't corrected by the shaving. So the tips of the valves will not be parallel with the rocker arm tips. The arms can twist as they move so it probably works out. If they skimmed the valve heads that will make them parallel but they'll have a slight side to side movement as they move up and down. Just one of those odd things to consider. So you're going to remove combustion chamber material from the small volume chambers to match them up? Make them all 54.8 CC?

That actually looks very clean. Not really worth doing more to. If you start using a detergent oil most of that will clean up as the engine runs. The brown color isn't from overheating it's probably just from blowby, combustion byproducts that have deposited up there. Not hurting anything. The brown color on the cam lobes is because the anti-rattle springs keep the rocker arms off of the cam base circle if the lash is set correctly. There's no rubbing there, which is good. It's also a good sign that you don't have any sunken valves since that will reduce the lash. Can't remember the year of your car (you should create a signature on your profile with information), but sunk valves were a problem before about 1976. Check the notch and groove on the timing chain sprocket to get an idea of timing chain wear. Make sure the tight side of the chain is tight and the timing mark is on zero.

Be nice though. The mechanic would have tested it while it was cold. So he/she would not have known, it would have worked perfectly like you said. Make sure it's nice and hot so they get full effect.

It's a fun puzzle but in the end, really, you paid for a service at a professional shop and they didn't get it right. I'd take it back. let them test drive it, and let them fix it. They have the tools and it should be a quick job. If you wait too long they can claim something new happened.

I think that he wants to use the bellhousing only. Sounded like it has a hole in the front case. Note to Z with a Z, these cars combine the bellhousing with the front case in the later years. So no separate bellhousing like a Chevy might have.

That's a nice diagnosis of a problem. Does it have the problem in all gears from a stop? It should if it's the pilot bushing. You're suggesting that the input shaft is binding in the pilot bushing and the shaft keeps trying to spin when it should stop. I'd guess that it might wear/break in. It looks like the Frontier uses a bushing and not a needle bearing like some do. So it will either wear down to the perfect fit, or heat up and seize. But, usually, holes get bigger as things heat up so it's odd that the problem gets worse with heat. Maybe they didn't seat it far enough and as the shafts expand the input shaft is actually pushing on the bushing. It might also be that it's not the bushing, maybe the clutch disc or pressure plate instead. Also, any chance they didn't get the clutch bled properly? The bushing is in your mind but it could be something else. I've never actually heard of that problem before, with a new bushing. You'll probably get some clues in the next few weeks.

Not if it is a 70-71 4 speed. Is there a picture? The early 4 speeds had the shift lever that hangs off the back of the transmission. Like the image below. http://www.carpartsmanual.com/datsun/Z-1969-1978/power-train/transmission-case http://www.carpartsmanual.com/datsun/Z-1969-1978/power-train/transmission-control

The COVIDActNow page added a new category. Severe outbreak. And a "Counties" breakdown. It's like watching the weather now. https://covidactnow.org/?s=1371355

Orange 72. Looks pretty nice. https://bringatrailer.com/listing/1972-datsun-240z-141/

Maybe it got clogged somehow. You said the problem follows the injector. Therefore, the injector is probably the source of the problem. Replacing the injector with a properly functioning injector should remove the problem. A problem with a single injector is not going to be affected by the CAS signal. https://www.enginebasics.com/Engine Basics Root Folder/Fuel Injectors.html

Wonder how he got it. Washington state's big money maker is down completely. https://www.seattletimes.com/sports/uw-husky-football/apple-cup-canceled-as-washington-states-covid-19-issues-persist/

Take it back and exchange it. It's no good. People like the Standard products. Here's one. https://www.oreillyauto.com/detail/b/standard-intermotor-5820/fuel---emissions-16775/fuel-injection-16471/diesel-fuel-injector-17271/fuel-injector-12310/8cc64890b5e0/standard-intermotor-fuel-injector-new/fj23/6010627/1982/nissan/280zx?q=fuel+injector&pos=0

It does sound like that injector is bad. I would replace it. Make sure you get a turbo injector. We might never know what's going on with your distributor cap.

Here's a nice graphic for anyone traveling. "Case per 100,000" probably correlates to probability or odds of contacting someone with the virus. More sick people in an area means you're more likely to run across one. Although, of course, in the Midwest there's a lot more space between people. Kind of odd that the numbers there are so high. The main stream media should be reporting things this way but they just like to show big sickness or death numbers. https://finance.yahoo.com/news/coronavirus-thanksgiving-college-kids-122920956.html

The specs look pretty good. I seem to remember that there used to be a warning on the container about the ZDDP content and catalytic converters. But I don't see it anymore. The Rotella is a low soot, low sludge formulation. Both sound good. Maybe they got rid of the ZDDP finally. I used regular motor oil, no ZDDP, in my two L28's and did not destroy any cams. I think that the ZDDP is more for break-in than long-term usage. Not even sure it's a huge issue with catalytic converters either, I think it's a long-term degradation of the converter if you keep using it, and if your engine burns oil. How did they used to break in a 280ZX engine or California 280Z engine and what did they run afterward? Always a fun discussion topic. https://rotella.shell.com/en_us/products/conventional-motor-oil/rotella-triple-protection.html https://rotella.shell.com/en_us/products/conventional-motor-oil/rotella-triple-protection/_jcr_content/par/productDetails.stream/1520976123954/02cdc4507e718cd0fc768d05faab7059e52f0938/t4-15w-40.pdf https://cen.acs.org/articles/84/i31/ZDDP-motor-oil.html#:~:text=ZDDP operates by forming a,tailpipe of an operating engine.

$28,750 for a modded 73 240Z is not bad. https://bringatrailer.com/listing/1973-datsun-240z-137/

The doors changed in 1977 for sure. Not sure about other years. There's no info about what car you're working in in your post. There are some good articles in the various "Resources" sections. https://www.classiczcars.com/files/category/10-tech-articles/ https://www.classiczcars.com/articles/ https://www.classiczcars.com/articles/body-paint/

More breeze is good.

Two in a month is bad design/bad parts.

I actually feel pretty lucky here in Washington. But it's still not good, and definitely going to get worse. https://komonews.com/news/coronavirus/covid-19-hospitalizations-at-record-high-in-washington-hospitals-work-to-keep-beds-open https://covidactnow.org/us/washington-wa?s=1360346

On your last picture, the wire that you are holding goes to the cylinder head temperature sensor (CHTS).

The point that gets overlooked and under-reported by the media often is the ICU capacity. Lots of philosophizing over death versus long-haul, young versus old, etc. but the other really big issue is that the strokes and heart attacks and car accident victims don't have anyone to take care of them if the beds are full of COVID-19 patients. Responding generally to motorman7, I have 246 on Ignore, don't know what he said. Sorry 246 but your comments are racist, and irrelevant.

Does it still run better when you lift the cap?

Tried to find one on Amazon just to get a view but there's too many choices for those words. I did find these though, which look really useful for our cars. https://www.amazon.com/DEDC-Universal-Slotted-Rubber-Medium/dp/B074TBZMLZ/ref=sr_1_31?dchild=1&keywords=low+rise+auto+scissor+lift&qid=1606085425&refinements=p_36%3A-80000&rnid=386419011&s=automotive&sr=1-31