Zedyone_kenobi

I am looking to pick up a replacement diff from one of these two parts websites. I have talked to both and they both seem knowledgeable and very nice. Does anybody have any experience with buying from these two vendors.

Drat, I told scotty to fix that!

I have a 1971 Z that has me plaguing the boards with this question and that, and to this boards credit, the amount I have learned is amazing. I recently got happy with the timing of my car in both base timing and max advance. On my test drive though the car does something particularly strange. At anything below 5500 to 6000 rpm the tach is dead steady. I mean new car steady. Very nice! However, when I rev it to this weird range the tach goes up smoothly and linearly. When it hits this band the needle swings back down to 3000 rpm and moves around strangely. The car still feels fine but acceleration seems to have slowed or leveled off. What would make it run flawlessly below this limit and then go electrically crazy above 5500 rpm.

You can save some money on rockers, as the stock ones were used by racing teams since the 70's. Your money is better spent on new stock replacements if you want peace of mind. 50mm carbs are borderline race only carbs and definitely race only on a 2.4 liter. Stick to the 40mm triples and you will be much happier even with your big cam. Make sure your radiator/starter/water pump are in great condition, as your increased compression, heat load, etc will take its toll. But before I can go farther, what are you plans for the car? Is it a track car. Daily driver. You need to know what its use will be. Keep in mind that the further you go from stock, the less reliable it will be. If you don't mind wrenching on it on a regular basis, then you can go more all out. But if you want to drive it regularly, then I would be cautious, to build such a high end screamer. Be honest with yourself, and you will end up much happier. Also, how are the rest of the mechanicals. Diff in good shape, half shafts okay. How are your brakes. Before you can go fast, you should probably be able to slow down.

I think I am in the same situation JoelH. I think I have excessive play in my R180. I have the clunk your refering to as well. I have checked my arrestor strap and my rear diff mount, and both seem in very good condition. My driveshaft has more rotation than I think a ring and pinion should have. I would like to get mine rebuilt, as it was original to the car, but at the same time getting a used one is FAR cheaper. We will see. I just need confirmation on my diagnosis. Once I get that, I can know how I want to move out. There is a good Z mechanic here in Houston, I may have to let him have a look.

Well first I want to thank those who responded with such great advice. I disconnected the vacuum advance and rechecked the timing. If you recall, with the vacuum advance connected I had 800 rpm 8 Degrees 2850 rpm 44 Degrees Now with the vacuum advance disconnected I had the following 800 rpm 8 Degrees 3000 rpm 22 Degrees So the vacuum advance was working overtime. Still I wanted to check out the inside of the dizzy to see what was going on with the weights down there to see if perhaps they had been tinkered with. I got as far as removing the pertronix plate. I never found the centrifical advance mechanism. There was another plate in there that I could have removed but did not. I need to look at a schematic before I tinker too much with that. However, I did find a wire form the pertronix, a little black one that attaches to the plate the pertronix is mated to that was disconnected. I attached it, and cleaned everything up inside. So really having done nothing but look at the pertronix hardware, nothing to it really, I put everything back together. I was leery of 44 degrees so loosened up the distributor and retarded the timing a tad. When I hooked up the timing light again to while the engine was running I had 5 Degrees advance at 750 rpm. Throwing caution to the wind, I hooked up the vacuum advance again and low and behold I managed 36 Degrees at 3000 rpm. Dumb luck, most likely. I have not driven it yet, but the way it starts and idles I am fine with. Very smooth and controlled. Next is the valve adjustment. Looking forward to that. Looks pretty easy actually according to that slideshow website floating around. Opinions. My next project after the timing is the rear end clunk. I am convinced that I have waaaay too much slop in my ring and pinion. I can rotate the drive shaft almost a half inch in each direction with the car in neutral. Not sure how to fix that other than tearing into the R180, may just try to find another one. Anybody have a 1971ish R180 laying around for sale!

Hopefully today my valve cover gasket will come in and I will be able to finish up the tune up. Question though, are there any advantages to doing a hot lash, vs a cold lash. I know the tolerances change a tad, but I would think the hot lash would be a little better in as far as accuracy goes. Just curious. Thanks. Also, what timing values on the low and high end should I be looking for w/o the Vacuum Advance hooked up ?

I just learned I should not have had my vacuum advance hooked up. Forgot about that, been so long since I had to set the timing. Also, to those who are wondering, I am running the pertronix ignition in the distributor.

Will you be selling these? Or are these just for you to let us know you have a sweet exhaust? I am interested in this.

Thanks, was researching my "How to rebuild your L Series: last ngiht and found that exact statement. So I should be looking for 5 BTDC and no more than 36 degrees at say 3500 rpm without the vacuum advance then. I will let you know, by the way I am running the Pertronix on my car.

Okay, I dont think I was completely clear with my situation, my apologies. Its been a long time since I had to do timing on an old car, my trans am ran a mechanical advance MSD distributer. When you check the timing, are you suppose to disconnect the vacuum advance? Gosh I feel like a moron for asking that!

I have checked my timing and at 700 to 800 rpm, I am sitting at about 7 Degrees of advance. Is this right? Also, just a note, at 2800 rpm, I am at 44 degrees. How does this stack up to what it should be?

71 240Z with 69569 original miles on the engine. Changed plugs, all were a lovely light brown color on the electrode but were burning cleanly and even. The last thread on each plug and the land that sees the cylinder was a a bit shiny black, meaning probably I have a tad bit of oil seepage down inside the wall. Car does not burn a drop of oil that is measurable, and never smokes. Changed out the stock vacuum advance as the diaphram was completely shot. I am happy to report my car almost eagerly revs to 6500 before any drama. I think the carbs may need a tiny tweak or two, but my 5000 rpm wall is gone and she pulls smoothly up the rpm band. No hurry to mess with the carbs right now, but will eventually do a rebuild on both. Checked the timing and I was pleased at the results. My only problem is I am not quite sure what the factory settings should be, but I am about to do a search. At 800 rpm, I am running 7 degrees advanced. At 2850 rpm I am running 44 degrees. I do not know if that is too much or too little. But that darn vacuum advance is advancing! Checked the engine vacuum at idle on the balance tube, and its sitting pretty rock solid on 17 in hg. Next up are an oil change as soon as I modify my ramps to fit under my spoiler and I think I need to do a quick valve lash. I hear some tapping going on that sounds like a V8 rocker arm. I have not run a compression check yet, but with the way the plug are burning and complete lack of burnt oil, I think it can wait. The car idles steady as a rock, the coolant is clear and clean with a lovely shade of green. I have no overheating issues to speak of and my oil pressure is good. At idle when completely warm its 15 psi, and at 2500 rpm cruising when warm its about 45 psi. This is with 10w30, and since we routinely hit 100 degrees in Houston, I am going to bump it up to 10w40 So far the car responds very well to all inputs. And I am pleased. I am still leary of the clunk when in gear, I dont know if my rear end, or if its a u joint at the front of the driveshaft. More fun to come!!!

Thats happening today! Finally get some quality time with the Z.

Actually truth be told, I think they are shelby rims.. I have the shelby centercaps.

So thats great, I have some Redline 75w-90 for the tranny, and I will pick up some 75w-140 for the rear end. I am a huge fan of Royal Purple products and noticed a difference in my Subarus over Mobile 1 even. d240zx2, I did not mention it, but I have some of those slotted mags sitting in my garage I would be more than willing to part with since I will never replace my panasports. If you need another set, let me know, you can have them for any reasonable offer.

OH man, I love the solutions the early pioneers of emissions took. The ideas are often creative. I am not looking to gain any HP or Performance. Mostly, It would make it easier to get my scrubber brush in there to clean up my manifold. Thanks 240ZX.. I would wager that I would have seen that if I blipped the throttle and saw it move, but alas, the diaphragm in it, as in my vacuum advance is long since rotted away. I cannot wait to get home and free up some dead weight. I think I will keep them and clean them up though and bag them. I may want to get new ones one day if I ever decide to do a complete restoration.

Does anybody have pictures of tokiko springs installed on the front of their Z. I was checking mine out on my recently purchased 71, and when the car sits at rest it looks as if the coils are almost binding. IF this is true then the car uses its bumpstop for almost its entire suspension... Now all I saw was the top portion of the sping, which may or may not have been progressive, so I may have more coils below the tire I could not see. I noticed this as I was waxing my rocker panels the other day. Just thought I would ask. THanks!

THats good to know. I was thinking somewhere in that range. Thanks very much for your quick reply.

When I bought my car, it came with panasports installed. The PO also gave me a set of 14 or 15" slotted mags that I have seen on many Z's. I have no intention on ever using them, and would like to sell them, but have no idea how much they are worth. What is a fair price. THey look fairly ding free, and come with Shelby hubcaps, but they need to be polished. Before I hit the classifieds, thought I would ask the folks in 'the know'

Kudos to you for making your Z yours! I am happy for you. Its stunning, and you should be proud.

pictures would help!:nervous:

I think these are just emissions parts. I am about ready to take them off, but want to be sure. I have looked them up in my how to restore your 240Z book, but they give little more than a name. I honestly do not see what their purpose is at this point. Perhaps they had something to do with some form of emissions equipment? The guys at hybrid Z said it has something to do with idle control? Any help would be great.

Bravo! Bravo! What an awesome garage!

From the sound of this, it sounds like I may just want to try to get a new strap and new diff mount. I may back the car against a curb and video what the diff does. If it moves, it may explain the bulk of my issues. As a rule you should always start with the simplest things first. Then work your way forward. THanks so much for your Video Steve. When I get on and off the gas like you did is when I hear my clunk. My arrestor strap when the car sits actually quite lose. I will look into the rear diff mount. If yours moves that much, then there is a good chance if mine is original, that could be the source of my problem. The more I think about it, the more I dont think its my half shafts. But we will check these out tonight. Again, thanks for going above and beyond the call of duty.