Captain Obvious

Got the chance to work on the metal base. Biggest problem is that I didn't make any templates for the base section, and I no longer have an OEM knob in my possession to compare it to, so I'm winging it from memory! Here's a very rough cut testing on the knob to see if it's even close to looking right. Here's my metal base finished and all polished up. And yes... It's real metal :laugh:: And here's my three knobs all together. I think the base looks acceptable for making it with no template. Haha! Not sure I could do it again, but this one turned out OK: I still need to apply some finish to the newest knob and figure out what I'm going to do for a shift map. I used to have a knob with a Datsun logo in the center. Anyone have leads on inserts that I might be able to use?

Learning as you go is great. Take some time and at least read through the tune up and engine fuel sections of the manual. It will not only add to the learning experience, but it will also help you communicate here. Not sure how to interpret your results with carb cleaner. Usually the typical reaction to a carb cleaner spray around leaks is an increase in the idle speed, not a decrease. Especially if you are running lean. What do you mean by "new" carbs? None of these carbs are new at this point, right?

Progress... I got the rough cut blank trimmed to shape. Here it is compared to my cheap and dirty contour gauge: And here it is cut off from the rest of the bowling pin: Tomorrow I'm going to work on the metal base. ninjazombiemaster, Yeah I remember that thread with the discussion about the shift map. I was looking at yours while it was here and I was considering trying to cast something with it, but I have no idea what I'm doing with that and didn't want to mess anything up. You know most of this is your fault, right? I was perfectly happy with my black plastic knob until I started messing with yours.

I've started my second knob attempt. This time I'm going to really trying to recreate the OEM knob. Step one - Here's my old black knob, and my second knob attempt at the very start :laugh:: Here's what I've got so far. Bowling pin is mounted and first rough cut sizing done: Hopefully more tomorrow! Yes, given enough time, of course! You, being learned in the field of theoretical math and physics, are surely familiar with The Infinite Monkey Theorem. I have one thing to say to you... Ooooo! ooooo! Eeeeeeek! Eeeeeeek!

FastWoman, I understand the juggling priorities issue completely as I am perpetually in the same situation. I've got so many other things I should be doing that I feel guilty when I'm working on the Z. :paranoid: Stack of cement board and boxes of tile? Been there too... Good luck with the project and hope you get your shower soon!! As for the AAR impact on idle RPM, now that I think about it, I have to admit that I don't really know how much of a change you could get out of one that is working properly. I've got mine adjusted such that my idle stays about constant at 800 RPM or so as the engine warms up. If I were to open my AAR up more, I don't know how high my cold idle would go. I suspect I could get a pretty high idle though because you see how small of a window I've got past my shutter when cold. I'm using less than 25% of what that AAR could flow. I bet my cold idle would be 2000 RPM, and as long as it could still close completely, my warm idle should still be 800 RPM.

When you say you have a leak in your throttle butterfly, I'm assuming you mean you have a leak around your throttle shaft where it meets the carb body? Your throttle butterfly is supposed to leak. That's how the engine gets it's air and fuel. But assuming you meant a leaky throttle shaft... I doubt you have enough of a leak to require 5-7 turns down on the mixture nut. If that truly is the case, then your carbs are all wallowed out and need to be repaired or replaced. I can't figure out what you are talking about when you say "the linkage bar/balance screw that shuts the car off smoothly". I have no idea what that means. Might I humbly suggest that you look through the factory service manual and use the same terms for parts that are in the manual. That standardization of terms would make troubleshooting a lot easier. :bulb:

Wade, I championed the exact same theory and it was brought to my attention that the cold clearance spec for the Z is smaller than the hot clearance spec. In other words... It depends on the application. Some engines get tighter when hot, and others (like the Z) get looser. I haven't gone through the analysis, but I suspect it has to do with where the aluminum is. Academic, but thought I would pass that on.

Haha! You looking for something specific? :pirate:

Wade, Yeah, you should be getting more than 100-200 RPM difference out of the AAR. Wonder what's wrong with yours... Haha! So you're thinking that I should get into the AAR rebuild business? What's a new AAR cost these days?

FastWoman, I think what you described to oil the pivot pin would work fine, but I'm not sure there is anything in there to rust. The shutter is aluminum, and I believe the pivot pin is chromed steel. Of course, there's the possibility that you have worn through the chrome plating on the pin and have developed some rust, but I think that's unlikely. Mine wasn't rusty inside, but did have some sticky oil residue from the PCV system. As for getting oily stuff out, the first thought is some kind of solvent, but I'm not completely comfortable with that approach. I know others (TomoHawk for example) have had good success doing that, but it worries me a little for two reasons. a) I don't know what kind of insulation they used on the resistive heating element and I don't know if it would like the solvent, and Some of the shutter blades I've seen have a coating on them that I assume is supposed to provide a thin elastomeric surface to better seal against the inside face of the high vacuum side of the clamshell. Problem is that I don't remember if that rubber type coating was on the Z car AAR, or another one from a different car. I've got a few of them I've messed with at this point, and I don't remember which had coatings and which ones didn't. If I had to guess, I believe the Z was uncoated so it should be OK, but you should take a look inside through the holes first to confirm that all you see is aluminum. Maybe just try to keep the heating element on the uphill side so it doesn't soak in the solvent? I'm wondering if your pivot pin has creeped out some like mine did. You could file the crimped lip off, poke around inside, and then epoxy it back together. Wouldn't be quite as field serviceable as what I've got, but you could file the epoxy off again in the future if you needed to get it open again. A little heat would soften it up too. Do you have a spare AAR or just the one that's on the car?

I understand. I'm in the same boat. I picked up those other wheels and have since decided that I would rather have a better original than a 240 or aftermarket.

I was expecting you to be asking about differences in the keys used for the American and European 260z. So for what you really meant... If you're that serious about it, you might consider making sure everything is in tip-top shape and then get a dyno run done to establish a baseline. You might be surprised by what you are getting out of your current engine.

I'll trade you a 240 "wood" wheel or a Grant GT. :bulb: http://www.classiczcars.com/forums/thread47775.html

The connectors are easy to install... Put the "U" shaped metal retainer clip fully into place before you push the connector onto the injector. The connector is designed such that the retainer metal will push out of the way as you force the connector onto the injector and then "click" into place once the connector is fully seated. No muss, no fuss. Taking them off is much more difficult than putting them on.

geezer, Thanks again for the info. I don't know how deep stain penetrates, but it sure does look like the wood color, doesn't it? Is your plastic insert split? It looks like a crack along the back top in your pic? I'm thinking for my next knob attempt I'm going to make an insert like that, but I'm going to make mine out of metal. Either aluminum (easier to work with), or stainless (will look more like the original and will stay shiny longer). hls30.com, Thanks for your info too. I've got a line on a solo retired pin that is just itchin' to be turned into a shift knob...

Thanks for the pics geezer. Your stock knob is certainly much darker than the other OEM knob pictures I've seen. Are you sure it wasn't stained darker than original? Maybe it was completely dunked and is stained on the inside hole as well making it look like it's the natural wood color? Speaking of wood types..... Anyone know what kind of wood bowling pins are made out of? :bandit:

FastWoman, The trickiest part was drilling and tapping for the screws to hold the clamshell back together. There isn't a lot of meat to work with there. I held the two clamshell halves together with a clamp and drilled the hole right on the seam between the two halves. That means for the first few turns of the screw, there are threads in both the front and back of the clamshell. Then, of course, once you get deeper, the front part of the shell ends and you've got a full hole in the back half. Doing a pretty shoddy job of describing that, I'm sure... What else? I used 2-56 screws for the clamshell. Small is more important than strong. The bottom hole is blind. Don't remember what size I used for the flat head screw on the shutter blade or the retainer for the bending element. Haha! Yeah, I use a stunt double for my photos. This is what my hand look like. It's kinda embarrassing...

Using a small spring washer under the original pivot pin would work in a pinch, but the problem is the additional friction that it would provide. You don't want any stiction in the pivot as the resultant hysteresis could cause in unpredictable operation. The flat headed screw makes it such that I can tighten the screw to jussssssst a thousandth or so before it starts to bind. That way, I have good tight fit, but still no additional friction. I also noticed that the original pressed in pivot pin had a tendency to loosen up after the blade moved around a few times. I wanted something with threads so that I could threadlock it in place and not have it loosen up by accident. Speaking of the calibration marks, you can see how I have my AAR adjusted: Once it's warm, the window is completely covered (as it should be), but as you can see, at room temperature the window opening is pretty small. Because of that, my idle doesn't shoot high when the engine is cold, but pretty much stays constant. In other words, the additional flow through the AAR doesn't actually RAISE my cold idle, but in fact makes my cold idle the same as my warm idle. I need to open it up just a little more. I was fighting a high idle condition because the AAR was sticking open, and I overcompensated a little.

Been a while, but I haven't forgot about this thread. I got the opportunity to pull my AAR off the 280 to take some pics of the modifications I made. Unfortunately I didn't take any pics of the work in process, but I took some of the finished product. To recap... I used a lathe to cut off the crimped over lip that originally held the two halves of the clamshell together, cleaned everything up, and made some improvements while I was in there. Here's a shot of the inside. My calibration notes W = "Warm", R = "Room": While I had it apart, I didn't like the way the shutter blade wobbled on it's retainer pin and didn't always align properly to make a good seal against the inside of the housing. This can result in an incorrect high idle, so I pulled out the original pin and drilled and tapped for a screw instead of the original retainer pin. I countersunk the shutter blade to accept a flat head screw and screwed the shutter in place with very little play. Here's a shot of the screw, and I am holding the original pin: Then to put it back together, I drilled and tapped three small holes to accept screws to hold the clamshell back together: Here's a closeup where you can see how the screw is installed: I also drilled a hole for a retainer screw to keep the bending element in place: Used a little RTV silicone on the bending element and also between the two halves of the clamshell and then tighten up the screws. It works much better than new! No binding, no leaks, and I can easily take it apart again if future cleaning is necessary. And just for illustration, here's a pic of the components:

Unless you got orangutan arms, you gotta ask the passenger to change the radio station for you!

I suspect you've got a vacuum leak somewhere and you are running way lean. Are you sure you didn't miss a vacuum port somewhere?

Got the second coat of stain on and here's what I've got. I've sent the original knob I had back to it's owner, so I can't do a side by side comparison for color, etc, but from the pictures, it looks surprisingly close for just happening to have a can of stain pushed to the back of a shelf in the basement. I've got some feelers out for some maple and some walnut to try again.

Hi Mike, Thanks for the pics. That looks fantastic. I don't know what you paid, but from the pics, they did a great job. Couple of questions if you don't mind: Are there finger grip indentations on the forward facing (unseen) side? Do you know if they completely removed the original rubber material before they started the reconstruction, and if they did... Do you know how they built the diameter back up before the final leather covering?

Hi Mike, Thanks much. I'd love to see some good pics of your redone rubber wheel. The "before" pics are less important... I know what that looks like.

Nothing? No info on anyone who refurbishes the black rubber wheels? And nobody wants to trade their cottage cheesy bubbly loose rubber wheel for a 240Z "wood" wheel or a Grant GT which already has the correct hub adapter? I figured people would jump all over a straight up trade offer like that... ? :paranoid: