Zed Head

The bottom ends on these engines are pretty durable. Might not be worth the time and money tearing it apart. Your list is kind of the typical small effect things that people do. You might not even notice a benefit over stock. If your dad wants you to get the car moving again, and you want to drive it. a simple head refurbishing might make more sense, then buy a separate engine to build. The EFI system kind of limits how much benefit you can get, without making certain things worse, like driveability and emissions. You never gave much history on the car and why you even wanted to pull the head.

That's a great picture and you probably know how lucky you were that it's in such a convenient spot. I was thinking more of the big cloud of bees that fly around aimlessly after the queen bee lands, until they finally find her and form that bee ball. I climbed a tree with a pruning saw, tied a rope to a branch with a swarm like yours on it, then cut the branch while my grandfather pulled the rope. He talked me in to it. Only got stung three times when the swarm let loose, but almost fell out of the tree on the way down at warp speed. Good old days...

See that? Another opportunity to pass on some knowledge, a correction of a simple error in nomenclature, turned in to some not-unexpected righteous indignation. Does it do anything at all for anyone but the author? Not really. The knowledge will die with the people that don't share it. For anyone that thinks the information is readily available for anyone that has a computer, do a Google on Photobucket. The people that own the servers that hold the knowledge will let them die with that knowledge.

After I wrote the comment I realized that it was almost perfectly balanced, and could be taken either way. Decided to leave it. Glad you didn't see it the bad way. It's an interesting car with what might be an interesting story. I would keep the history and restore it as Japanese G-nose (I think that's what it;s being represented as), that made its way to the states. It's a look at how modifications were done in Japan, if I read the story right (the roll bar, for example). That is fascinating history, to me. There's probably plenty of factory original restores out there.

Sorry for the comment, it was off-base. Thought I saw another fin in the water. Seems like the real question should be if the car should be "restored" to its modified G-Nose state, or taken all the way back to its original state. I've made comments about restoring before. Why go all the way back to what the factory produced unless the car was unmodified and is just worn? Anything else is not really a restore but a refabrication, or some similar word. I'd rather see the car in some attractive state and hear the story of how it got that way, than throw away all of its history. If the history is interesting, then keep digging to get the details.

The low VIN club guys have to get their subtle digs in. Your car (and you) don't meet their membership requirements. Everything is there to make a running driveable enjoyable 240Z. Value will be determined by the next buyer. Good luck.

My grandfather was a beekeeper. A new swarm appearing from nowhere is a spooky thing...

If I had a carb'ed car I'd use the big giant EFI filter before them. I've been spoiled. The filter is big so that the pressure drop is small, since the filter media area is huge.

I have Jon Voight's car. Or maybe John's...

A picture of the roll bar would be interesting, along with any suspension modifications. There are really no signs that it ever saw a race track in your pictures. Most people don't put roll bars in their street cars. I take it though that the man issue here is whether or not the Nissan factory was involved. Maybe it was a Nissan dealer. Don't know how the dealerships work in Japan.

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..