Zed Head

What year, how many miles, condition of the interior? Do you have any more pictures? It looks nice but you've given very little information about the car.

Shake the car vigorously side-to-side and you'll get more of that.

The rust is heavier than the liquid fuel and sits on the bottom of the tank. It gets shaken up and suspended in the fuel as you're driving then sucked in to the pump and lines . You can either let new filters clean the tank for you or drop the tank and shake the rust out. That's your essential choice right now. This is a very well-known problem. No real mystery here.

He should have disclosed it or they should have one of those "about the author" things. Hagerty says Concours quality 70 cars are only up to the high 50's. And they, apparently, by their own words, base their estimates on actual sales. I can't imagine that any decent author doing the most basic research did not see this data. But he wrote $75,000 anyway. https://www.hagerty.com/apps/valuationtools/1970-datsun-240z https://www.hagerty.com/valuationtools/About-our-prices

Fuel pumps can heat up and lose pressure. Then they cool down and start working right. I've had one that did that and so did FastWoman. But they can heat up if they're working too hard. I'd replace all of those filters, then let the pump run by moving the AFM vane and see how the pressure does. You can run the pump without starting the engine and learn a lot.

Shouldn't the wheels be on the other side? The impression of movement and sped would be greater. Looks like they're scooping air as they are. Pretty sporty looking though.

Here's the page from the 1976 Owners Manual. My 76 Federal model has a Non-Catalyst plate on the door jamb and no light.

Only for the sake of the original topic - do they discuss Helmholtz anywhere? Helmholtz seems like an unnecessary complication.

I just wanted to see the before and after, that's all. Weird that HKS designed the original system, but it didn't have these devices, did it? But their aftermarket product needs them. Does the factory system drone? Not picking a fight, I just see some aftermarket sales work happening. I tend towards super-cynicism.

But in the end he still "took a shot in the dark" on tube diameter. And his screen name is Smokeshow. Seems like you could build something like that but with an adjustable internal end piece, on a long bolt or piece of Allthread rod. Run the internal plate back and forth until you hit that magic spot. That web site really locked up my browser, caused classiczcars.com to go unresponsive.

These devices are really just resonance dampers. Does HKS describe Helmholtz resonance or is that an assumption? I checked their web site but don't see any technology described. If you had a before and after with the 370Z system that would be pretty conclusive.

Winner, winner, Chickenman dinner...

My more direct question should have been "does it drone without the (anti-)resonators? Serious question, just wondering. Could be that the pre-muffler (anti-resonance muffler) works best with six exhaust pulses, but not with three. Just trying to distinguish why they work for some but not for madkaw.

Wow. Our old Z's should be huge.

Have you tried the factory pre-muffler? It's true name/purpose might have been lost in translation. Seems like we should be using the word anti-resonance, or resonance-damper also. Resonance is what causes the drone, I believe. "Glass packs" are the typical substitute for the pre-muffler. Doesn't the 370Z have catalytic converters? Kind of confounds the cause-effect equation..

That broken rusty bolt piece can exert a lot of resistance. Rust is weird stuff, it actually grows as it eats away the base metal. Oxygen atoms are added to the metal that is pulled off. It will expand to fill every void, and when the growth occurs in expanded cylinder head holes, the result is a compressed pile of rust when the head cools down. Rusting rebar cracks concrete even when its buried deep. Called "spalling". It's powerful. It's a major cause of bridge damage. Here's a fuzzy picture I took of mine right after I finally rocked the head off of the bolt remains. That pile of rust was packed into the hole. Here's another, more clear.

In 4th power is transmitted directly through the main/center shaft. In 1 through 3 and 5 it uses the countershaft. So noise in those gears could be a countershaft bearing going bad, or already damaged. If you haven't changed the transmission fluid yet, you might find metal parts on the drain plug magnet. If you decide to change the fluid, which you should, make sure that you remove the fill plug first, to be sure that you can refill, and to avoid sucking dirt back through the vent when the old oil comes out.

Does it make the noise when you shift, or while you're driving in one of those gears?

Here we go. The author is a car salesman. Not that there's anything wrong with that. Keep pumping. http://www.roadandtrack.com/author/2767/colin-comer/ http://colinsclassicauto.com/

Seems like he would have just written that if he wanted to. The article has an odd tone to it, like the author just decided on a theme and tried to fit the reality to it.. The 280Z is often bashed because it's the "GT" version of the 240Z. The 240Z purists usually talk about the raw sports car nature of the 240Z and how it was lost when the GT-like 280Z was introduced. But this guy starts by describing the 240Z as a GT car and comparing it to GT cars of the day. GT, GT, GT.... Seems way off base from the first few sentences. Apparently he owned one though. And like many early 240Z owners, thinks it's worth huge money now. Seems like could tell us more about his $75,000 car. It's not even "low VIN", it's over 500. Is anyone aware of a plus 500 VIN 240Z that sold for close to $75,000? Lots to suspect in this article. But it is an interesting read. Doesn't really seem worth much though, in the big scheme of things. "CC" is the author. I couldn't find any more about him because that is one screwed up web site. Keeps reloading more junk before you can click on the bottom links. "I bought the finest original Series 1 car I had ever seen—low miles, flawless original paint, and an interior and chassis you could eat off. It wasn’t one of the first 500, but it was a very early production car. I paid $15,000, probably a record price at the time. I enjoyed the car for a few years and sold it for $25,000. That buyer later sold it for $40,000. Today, the same car is likely worth closer to $75,000. "

"They". The internet is full of bad people. Stay away from the internet. It's bad.

Without at least a few details it's just guys saying that some random person made them feel bad and they blame everybody for it. I know that John Coffey was a moderator over there. Because he deleted some of my posts. But he seemed to be popular over here. That's what I mean about smearing unintended people. If you're going to be negative you need to work much harder at it than being positive. Don't post negative comments just for your own sake. Do it right. Edit of edit - Be constructive.

No problem Site. Tony D does that to people. He is also apparently a nice guy in person. His internet persona is the bad one. Maybe people experience the words from the internet in different ways. There's probably a good psych study there somewhere. If Google hasn't done it already. I wonder how zcar.com survives.

Still no backstory? Maybe you can't even remember. Just smear everybody. Tony D is a major supporter of that site. Pretty sure he's donated hundreds of dollars. Ironic, I think.

I thought of something last night that might help. Feeler gauges. Stick two thin ones in to any gap you can create, then stick another between them as far as it will go. Press on the blade while you hit with the hammer. The gauge blade should slide in a little farther with each hit. If you can't even get one blade in, then pound wit the hammer while you try to stick the blade in. You might have to work a gap open a few thousandths of an inch at a time. Maybe you're trying to do too much at one shot.