sonomaz

I'll try to get a photo up soon, but all other rockers have their wear pattern in the center where it belongs. I woundered about the divot being toward the back and for some reason I think it moved backward as the rocker wore. I work this through my head because I know the geometry changes as the pad wears away. Also my confidance is high that it was set right at the begging but I have no proof. As to engine bearings, their going to have to hang in there. I'll take some precautions to remove what I can but an engine tear down is out of the question. As to changing valve springs for break in, that dosen't seem practical either because I would have to pull the head to change them and that also ain't in the budget. Don't get me wrong, I think your suggestion is very wise. Please stay tuned because I will need advice when I get a replacment cam and it is time to go back together. You guys are great.

Thanks for the feed back. The Cam was ground by Crane Cams. It appeared to be a new core and not a regrind. I do not recall any casting alpha-numerics but there was a purple paint swatch on the shaft. I am refereing to past because I have sent it off to Crane for evaluation (and hopefully a replacment). I can't recall if the rockers were aftermarket or not but I have no recollection of them comming in a "Nissan" red and blue box. I may have gooten them from Motorsport Auto but I am not certain. I have the other eleven rockers so if there is some way to determine their origin I can look (I sent the bad one iwth the cam hoping it will provide more info). Your statments about hardness makes a lot of sense. I could see how one rocker may be slightly harder than the others which would explain only one lobe failure. Any idea who could measure the hardness of the others? I would expect to close that question I would also have to have the cam measured. Paul

I figure I have twelve hundred miles on my eniginge. At eight hundred miles the rockers sounded like they were loose. At about a thousand I adjusted them. I did this while it was hot so I put to much hustle in it to finish before it cooled. After there was no difference in the sound. I decided to adjust them when it was cold so I could tke my time and get them all the same. This turns out to be a good plan because the adjustments ranged from 0 to 0.012 and averything in between. I have a Crane cam and the spec card says 0.008 for Exhaust and 0.006 for Intake. While doing this I did a very close inspection and this is what I found. I appoligize for the out of focus image but it was the only one I could get that showed the ridges. As soon as I found the damage I came here and did some searches and found a thread where Paul Rushman had responded to someone else with cam damage and suggested they flush their oil system, drop and clean the pan, dissassemble the oil pump and clean it and of course change the oil filter. I thought that was a little dramatic. Then I pulled the rocker out and the thought of all that metal floating around in my engine and suddenly it seemed like more than a good idea, it seemed like a requirment. So that leads to my question of "what happened"? There was lots of moly lube on all lobes. The plug is in the back of the cam. All other lobes look beautiful. I had drilled the head oil supply jet to 0.125 as suggested by " how to modify your Datsun motor". I am using a spray bar that is new. The valve in question moves just like the others. The rockers where new. The wear pattern on other rockers is where it is supposed to be. There is no sign of spring stacking. All valves are at the same closed height. I packaged up the cam and sent it back to Crane to get their input. It should get there about the same time huricane Fay departs. Any thoughts are welcome.

Does anyone know what material L-6 rocker arms are made of? I know they are two pieces and the large piece appears to be cast iron with a wear pad inserted. Mostley I am just curious. I have a cam lobe failure right now on the #2 intake. I did some searches here and it looks just like the other pics ( I'll try to get some pics posted soon) I found here. The entire motor has about 1200 miles on it so I am assuming it got starved for oil at start up and I may not have broken it in properly. It is curious only one lobe went bad though. The cam, springs, and retainers came from Crane and I got the rockers from motorsport.

Mike, Unbelievable work! That kind of exstensive wind tunnel testing on a 30+ year old car is ... awsome. Looking at the data on the sticky, why is there such a difference between the second #2 and #19? Looking at the pictures thay both appear to be nearly stock first gen Z's. I know a lot of people have said it already but thanks to all of you! Paul

I'm sitting here on the couch watching clash of the choirs and selectied the link to your dyno run and I think you are in the running to win, so what number are we suposed to text? Seriously, I just love the sound of that straight six through a free flowing exhaust. So cool when you hit top gear and that note just slowly rises to that wail of "this is it! this is my best effort!!!" Awsome, dude. Paul

Rod, This kind of freaks me out. The strut should fit close, alomost snug, to the inside of the housing. I think you should put another call into Tokico to make sure the space you have is OK. My concern is the bottom of the strut will flop around inside the housing during hi forces like cornering. As far as oil in the housing I didn't add any, but actualy put a small hole in the bottom of the housing so water would not accumulate inside the housing. There is no seal at the gland nut to keep stuf out or in. Not sure it is cool but that is what I did. Paul

Well said John and that's where I hit a problem. I could not find DOT approved harnesses (maybe I didn't look hard enough) and Simpson clearly states they are not DOT approved. Replacement belts for a Z are old and used or if you are lucky to find them 35 year old NOS! Why wear these at all? So next issue is how do you mount racing harnesses? The stock location for the shoulder belt is no help and now you are looking at a modified roll bar that puts a steel tube 2 inches behind your head. What's a Z guy to do? (I'm back on the "internet engineering masturbation" thing. Its a lot of fun!) Paul

This is the second time in two days I have seen some amazing pics of S30 sheet metal that is invaluable to all of us. Those door pics are excellent in showing how little there is between your left elbow and the car in the next lane. The other thread was "1971 240z restoration PICS" by wickiewicked240z. I think both of these threads should be stickies because of there valuable pictures. The tube in the door got me thinking. I like that idea alot, but, if it holds you put all the force on the door jam. On page three of this thread Austin240Z posted the pic of the wrapped up Z and it does not appear that the front door jam held. It looks like the dash (I’m assuming, can't really see it), front door jamb, "A" pillar and cowl all collapsed. Granted a Hummer is not a telephone pole and vice versa, but it does make you wonder if the tube in the door is enough. Paul

Wikie, Wow! Just plain wow! The pics you posted of the body after media blasting and priming are priceless!! How many of us want to know what is under that carpeting or under the dash and now with those pics it is easy to see. I wish I had found this when you first posted. Clearly this car is going to be spectacular and with your excellent documentation the rest of us really benefit (God, I love the internet!). Please, please, please keep posting pics and descriptions of your progress. Paul

This thread really caught my attention but before I wrote I wanted to do some research. If your a geek like me try CDC.gov and IIHS.org for statistics. This is your tax and insurance dollars at work. What I found from 2003: Unintentional injury is the leading cause of death for ages 1-45. Of that Motor Vehicle Accident is number one for ages 1-65. By the way MVA is twice as large as the next category (which is homicide for ages 15-34). In other words if you want to be safe don't get in a car and stay away from other people who have guns. So I was ridding with my wife in her Lexus RX and thinking about this thread. Her car has a huge crush zone, energy absorbing bumpers, drop out engine (engine breaks off the mounts to absorb energy, totals the car), front air bags, tensioning seat belts, and on and on. (oh, forgot to mention the cruise control that slows down when it approaches another car from behind). That’s just for front end protection. So how do I compete in a head on in my Z with this goliath? What I have is a roll bar anchored to the wheel wells and a solid crossbar behind the seats. My Simpson belts are wrapped around that bar. Other than that I talk to Jesus often while driving. For side impacts I got nothing but 18 gauge sheet metal. Paul

OK, What are the numbers to this weeks Mega Lotto??!!! Nice Score!!!!

You need to get back to basics. Hard to believe but the SU's are pretty good carbs when set up right, and you should not suspect them unless you have a smoking gun. Unfortunatley back fires out the carbs are not indicative of carb problems. It indicates electrical or mechanical problem. Before anything check your fuel filter. If you can not breath easily through it, replace it. This is a problem area bacause it does not cause issues except at wide open or half open throttle conditions. The low cylinder pressure concerns me even if it is consistant. Did you check the compression with the throttle wide open? If you did, I would expect pressures in the range of 150-175 for a healthy engine. If you did them with the throttle closed they should still be up around 100-125. Before you do anything more check your valve lash. For a hot engine I think the valve lash is 0.010 for intake and 0.012 for the exhaust. Check your manule. Afterwords, check your compresion again. For electrical just change everything! I mean everything, because it is just easiest. It kills me the time people spend to track down a bad spark plug wire when the whole set costs $25 at Kragen. Cap, rotor, points, condenser, wires, plugs, change it all. Then check the vacuum and mechanical advance on your distributor. Slip the rotor on the distributor shaft and try to twist it. If it moves freely (there is spring resistance to overcome) it is probably working fine. Suck on the vauum advance lint to the distributor if the points plate moves it also is probably working fine. Start it up and set the timing between 5 and 10 degrees advanced. If you have done all this and still have problems, you still cannot blame your carbs until you do a few things more. Disconnect every vacuum line from your intake manifold and plug the ports. Caution, do not mistake the bowl vent lines for vacuum lines. These must stay open. If it runs great you have a vacuum leak. Check all the lines you just disconnected. If you are still haveing problems, NOW is the time to dig into your carbs. Two reasons 1) you have eliminated everything else, 2) you have done everything you need to before you tune your carbs. Ready? Shut it down and remove the air cleaner. Set up your tuning tach/dwell meter (your dash tach does not have the low RPM resolution for this job). Reach under each carb to the jet nut. Bend the stop tang out of the way or remove it completly. Screw the adjusting nut (it is not six sided, it has a real strange shape to match the stop tang that limits adjustability, an old smog thing) all the way up until it stops. Count carefully and back it out two turns. Repeat this on the other carb. Now, find the idle stop screw and back it off until it does not touch the throttle. Advance it forward until it just touches plus two more turns. Repeat on the other carb. Start the engine and run until hot. Place the flow meter over the front carb (you do have a flow meter, don't you? No? Get one from Edelbrock) and set the dial so the meter float is at the middle line. Place the meter over the back carb and adjust the idle stop to put the meter float at the middle line. Check both carbs to make sure they are even. Check your tach. Turn both idle screws the same amount until the engine is idling at 800 RPM. Your doning great! Now turn both neddle adjusting screws a quarter turn at a time OUT. Do this until the engine slows slightly (should be 1 turn max). Now go IN past the smooth idle part just until the engine slows again and return just until you ar at the smooth, fastest idle. Now check your idle speed and reset to 800 RPM again. Hang on, you are almost finished. At the top of the intake manifold neer the throttle linkage should be a screw the can push on a flat tab on the linkage. If it is missing do not be surprised the car is 30+ years old. Turn that screw until the engine is running at 2000 RPM. Set your flow meter on the front carb again and put the float on the middle line. On the connecting throttle shaft there are two screws. The one near the front sets the smog idle speed, forget about it. The back screw sets the high speed balance between the two carbs adjust it until both carbs are flowing evenly. Congratulations YOU, have just tuned a 240Z. You should either have a smooth running car or have found a serious problem along the way. Let us know what happens. Paul

Go to this web sight and order a set of these! They are worth every penny. My Z is a 72 with a set of Z-Therapy carbs and it runs great. http://www.ztherapy.com/ So a couple of things to know before you just slap on new carbs (or remanufactured in this case). 1) your engine needs to be healthy with good compresion in all cylinders and no major oil burning and no flat lobes on the cam shaft. 2) your engine needs to be in tune with an operating thermostat (170 or 180 degrees F will work fine). Timing must be acurate and the valve lash adjusted properly. Do a full blown tune up with points, cap, rotor and wires so everything is working. 3) Your carbs MUST be tuned properly with the choke cable and linkage adjusted and working. If you get these three things set up, then on a cold morning pull your chock lever all the way back. Keep your foot off the throttle. Your engine should crank several times before a single fire and then light right up to high idle. Wait a half minute or more until you hear it start to flatten out then slowly un choke to keep the motor smooth. After about two minutes you should see the temp needle rise slightly and you are ready to roll!! "Wait" you say My Z is a 73 or 74. Stop I say do nothing until you get the ZTharepy conversion kit to retrofit 72 or earlier carbs. Thats a must. The workst FI on the planet is better than those boat anchors. Good luck!!!

Just a wiled thought but if you had video of your real wheels at launch you may be able to sort this out. I would think up and down movment (relative to the body) would simply (!?) be suspension tuning, while front to back would be stability ie worn bushings or a loose link.

Hey, it's a beautiful day, a little cool, have to run into work, think I'll take the Z, put a few more miles on it. Where is that siren comming from, not behind me? Holly crap, on the right and that ambulance is going to cross infront of me against the red (green to me)!!! Jam the brake pedal!! This car stops fast. BAM!!! The bastard was tailgating me all the way up the highway. I took it in to Body Best in town and Dino assures me it looks worse than it is. The silver linning to this cloud; I get a new, replated rear bumper. Be careful out there, people.

The idea of a Morris purist becoming indignant because you put a V8 in one make me laugh so hard I get tears in my eyes. I consider myself a Z purist and the idea of any engine swap gets my attention very fast! I just love how versital this car is. No matter how crazy one idea is, some one comes up with another!! What buggs me about a SB Chevy in a 32 Ford roadster is its so common! Can't you come up with something original? Two swaps I want to see: 1) A Turbo Subie in a Z WITH AWD (serious fit problems here) 2) A Deisel VW in a Z (seriously modified of course like turbo, nitrous, and propane!) Go wild!!!

I'm not giving up on this issue yet. Edelbrock sells 350 Chevy crate engines that put out 425 hp. That works out to 74 hp / liter (425/5.74). With that number we should get: 2.4 l 177 fwhp 151 rwhp 2.6 l 192 fwhp 163 rwhp 2.8 l 207 fwhp 176 rwhp 3.0 l 222 fwhp 189 rwhp OK so these numbers aren't steller but this is compared to 30 year old tech. With some serious tweeking an N/A 3 liter should be pumping out 200 rwhp. So what will it take to hit this magic 100hp/liter mark? I realy want to know.

From this to this How is that for some pics, eh?!!