Captain Obvious

Hmmm... Not sure I explained my concern properly. My concern isn't when the switch is in the disabling position. I believe it is easy to short the spark to ground. Even on the high side... No problem. My concern is what happens when the switch is in the normal "non-disabling" open position. The concern is what prevents the spark from jumping across the open contacts in the switch (where you don't want it) instead of jumping the gap at the spark plug (where you do want it). The simple answer is "distance". But distance takes size, and size makes for non-discreet. And don't think for a minute that just as long as the gap inside the switch is greater than the spark plug gap that you'll get the spark only where you want it. Not only is high voltage a little unpredictable, but the desire for the spark to jump the gap actually decreases under compression. That means you'd need something significantly larger gap at one atmosphere. So I'm back to a big 'ol knife switch mounted on the inner fender well. Label it "RUN" and "STOP".

Actually, I believe the rivet is part of the current path, so it needs to be a good conductor. Thankfully copper is a common material used for rivets and they are easy to find. Even more thankful though... Replacement used switches are easy to find as well. Probably even easier to find than the correct sized metric rivet.

Thank you! thank you! That looks just like the parking brake handle in my car. it's a little embarrassing when I can't even remember what I did!!: Also what is that residual pressure valve? Never heard of that... I'll have to read up. But in the meantime, won't any residual pressure in the rear lines encourage the rear shoes to drag? Is that an alternative in case the rear auto adjusters don't work right? And lastly... You absolutely MUST get a couple pics of the shell in the boiling acid!! That's going to be a site to behold! (as opposed to a sight to be unseen). @siteunseen

Haha! Well need I remind you that I'm not a professional, so just keep that in mind with any advice I may espouse. May I offer you the use of my surface plate? My project du jour is replacing my original throttle body bushings with Delrin bushings, and I whipped the granite out the other day to check the mounting surface. (Actually, I just took the plate out to take a pic, but it looked wrong naked, so I plopped the throttle body down on it for the pic): I don't foresee needing it again until the spring at least, so it's yours if you would like to borrow it. Like I said, it's no Starrett like the nice one I'm sure you used at work, but it's good enough for the home shop work that I do.

Problem I see with having a way to short the high voltage side to ground is that the spark is likely to jump the switch to ground even when you don't want it to. See all that thick silicone insulation on the spark plug wires? It's there because you need all that insulation to keep the spark contained and prevent jumping to ground. I'm having a hard time coming up with anything discreet that can handle the voltage when it's supposed to be open. I mean, I can picture a huge knife switch with contacts two inches apart, but that's not discreet. I think it would be better to just disable the circuit on the primary side. Is there some reason it's more desired to do the disabling on the secondary side?

Takhli, I recommend that you get yourself a small granite surface plate for that kind of work. Haha! I'm no machinist or engine builder, and I have one. And despite the picture of that beautiful Starrett that you and I would both probably love to have, I'm not suggesting you need to spend big bucks. But I do think seventy dollars would be well spent to purchase a small import. For $67 plus shipping, here's a 12 x 9 x 2 thick example from MSC. "Shop or Toolroom Grade, 0.0001 Inch Unilateral Tolerance, Includes Certification": http://www.mscdirect.com/product/details/00150003 That would be large enough to do things like adjust thrust bearings and check main caps for flatness, etc. And according to your claims about your door, it would certified to be at least twenty-five times more accurate. Matthew, I'm a little reluctant to go into any of the other stuff above because the storm that I ignited seems to have passed and I certainly don't want those clouds to come back. But I wanted to explain that as a fellow Z enthusiast and member of this forum community, my loyalty is to you. With that in mind, I saw a questionable tool being used by someone in your employ for something important to you, and as your ally, I thought it would be a good idea to suggest the correct tool. It's easier to get good results using the correct equipment in good condition. It's the less common guy who can get the same good results from sub-standard equipment by making up for shortcomings with understanding, expertise, careful technique, and of course... Time. Based on the workmanship details posted so far, I suspect Takhli actually IS one of those less common guys who has a true understanding of the concepts behind what he is doing and can get the same results from sub-standard equipment. But even with that as a possibility, I just want to make sure you are getting what you're paying for. It's also potentially future trouble for other people trying to use the same alternative tools without having the understanding and expertise necessary to achieve the desired results. In other words, I don't think the phrase "Hey, take this over to that door over there and make sure it's flat." should become common workmanship instruction in the world of engine building. nor do I expect to find that suggestion in engine building instruction literature. But the bottom line is that I want you to be happy with what you get, and was just trying to help achieve that end

"bench top is a solid core door -- I know its dead flat" Ummmmm...... OK?

the_tool_man, I poked around a little with the concept of using it for an EFI controller. One of the early problems I ran into is that there is a lot of support software downloaded to the device (to make it Arduino) that I'm not comfortable having in a finished piece. If I'm going to trust the reliability of my car to something like that, I want to know what each and every line of code is doing. And with all the overhead and debugging code (that I didn't write) that's required to be in the device, I can't be that sure. That's one of the tradeoffs for being easy to use.

I have no idea. I was just jokingly poking the nest and trying to stir up trouble between dissenting exhaust system manufacturers camps.

HEADER FIGHT!!!

And I'd love to hear 'em! Here's to hoping we can get together someday!!

Haha! I've never heard that one before. I've heard "Drive it like ya stole it", but your version is rougher.

Glad to help. And your car is going to be awesome!

Gotcha. I thought the OEM style moustache bar bushings were impossible to find. Good luck with the work, and if it comes to it, I've had my brake booster opened up recently and have a bunch of pics and knowledge of the internals. Short story is that I bought a rebuilt booster a little while ago and wasn't satisfied with it, so during this off season, I took my original one and the rebuilt one both apart and reassembled one good unit from the best parts from the two. And even with going through that effort, there were a couple metal parts for which I didn't have a badly corroded replacement, so I made some new parts out of stainless so they wouldn't suffer the same rusting problems as my originals. Anyway... I hope you don't drop the reaction disk, and I hope you don't have to take the booster apart.

Actually, that's exactly what I was expecting. Tank or APC or something! Oh well, I thought I could coax an interesting story.

So from that, I'm guessing that you were planning to use poly and didn't realize that you need to leave the outer sleeves intact and just get rid of the inner sleeve and the rubber? If that's the case, then that's a bummer. So, were you actually able to find new OEM style moustache bar bushings? I thought those were NLA and gone from the face of the earth.

OK, I just gots'ta know... What piece of equipment is that mini-anvil made from? Have you got a pic of the origin? I'm sure it's something interesting!!

Haha, right you are! Glad to help. Unless you're in a hurry though, I'd suggest you give it a day or so to see if anyone else chimes in with simpler / better ways to check for fluid inside there? Fishing that disk out is a PITA.

I don't have any links for you to how-to's, but I've seen several pictures of engines/tranny assemblies still sitting on motor mounts on the cross member with the whole thing still sitting on tires. In other words, it's completely possible, and looks easy. I'm not sure if that's the recommended way to do it, but if I was taking the whole thing apart, that's what I would do.

it being dry when you removed the master cylinder means that someone, prior to you, has already replaced the failed master cylinder. That's good. And depending on how quickly they noticed and addressed the issue, your booster may not have sucked in a lot of fluid. You can check for fluid inside by pulling off the aluminum parallelogram where the master cylinder mounts. Then pry out the vacuum seal and remove the output shaft (the part that pokes the master cylinder). Once you have that output shaft out of the way, you can look inside and see if it's wet. Maybe stick a paper towel in the hole and reach around to see if it mops up anything? If the paint inside isn't peeling, and the spring is all shiny like, then you're probably OK. And then you can spent an hour or more trying to fish your reaction disk (which fell out of place when you removed the output shaft) out of the clamshell.

Have you considered one of those ricer tips the Hondaboys run? You can get them quite large. (Actually, I just had to come up with something to say to add my name to the amusingly growing list of people providing non-answers to your question.)

I don't have anything to add about the suspension work, but from looking at your brake booster, it's clear that you had a master cylinder rear seal failure at some time in the past. And if that's the case, it's likely that you've got old moisture laden brake fluid festering inside the booster eating the paint and rusting the metal bits. The longer it's in there, the worse things will be.

Wait... Is that your car running on that nut-brown gas??? Must have been quite the surprise when you drained the tank to find it looked like that!

I was thinking the same thing. I can't believe it actually ran on that stuff!! I ran my 260 for a little bit on the old stuff from the tank and it left this very sticky residue all over the insides of the carbs and intake manifolds. After five minutes of running, the throttle butterflies got sticky and would hang up just from the glue. Gross.

I think we're talking about different tubes. The 73-74 tubes I was referring to are screwed into the bottoms of the carbs, not the intake manifolds. The faces of the 73-74 carbs have these trapezoidal shaped holes for water passageways that they could have used to pass water through the spacer and into the carbs (like the 72's), but they didn't. They chose to plug those holes with rubber plugs and drill and tap new holes into the bottom of the carbs instead. Then they screwed metal nipples into the bottoms of the carbs for coolant inlet and outlet. Here's a plc with a good view of the coolant tubes and the faces of the flat tops: The holes I think you're talking about are on the intake manifolds - Four holes on the front one, and two on the rear? Four of those holes (the rearmost four threaded ones) are to mount the idle bypass tube for the 73-74 tubes. Note that one of yours has the twisted off remains of one of the idle tube retaining screws broken off stuck in the hole. Doesn't affect you, but that's what that is. The other two holes (at the front of the front manifold) with the vacuum nipples pressed in are for constant vacuum sources and were not used for distributor vacuum advance. Probably academic, but those vacuum holes were originally used for a) the throttle opener device, and 2) the anti-backfire valve. The vacuum advance should come off a ported source on the carb bodies, not the intake manifolds. Here's a crowded shot of a mostly stock 260. You can see the mounting screws for the idle screw, and the bundle of snakes of other vacuum lines, etc: As for what to do with the holes... I believe the holes for the idle tube are blind, and you can just leave them open. The other holes with the vacuum nipples, you'll have to do something with. I don't know how much emissions stuff you're planning to run, but you might need one of them for a throttle opener system? Other one just cap? Or get elegant and pull the tube out and weld the holes shut?