pbarcher

Hi All, It's been a long time since I posted, but have done much work on my 73. In 2013 I bought a set of the reproduction springs from Carl Beck, who advised at the time that I cut the springs because my KYB shocks might cause the car's ride height to be too high. I just opened the package of springs and noted that the springs have no "flat area" on the top and bottom of the spring to seat square. Is this correct? I want stock ride height, and any advice would be greatly appreciated. Thanks. Peter

I had a similar problem with the driver's side and was able to get used parts from zcarsource.com Peter

Hi Guy, I'd like to join you, but I wouldn't be competitive with you two! Eiji is almost finished with my car, and I'll be posting details after I've had a chance to drive it. My goals were modest, so I kept the L24 block and crank, bored to 86 mm with DSI forged pistons. Following your advice, I used a P79 head modified as you have except for a less aggressive cam. Balanced and blueprinted of course, with ztherapy carbs. Aluminum radiator too. Peter

Guy, Tell us about the engine in yours. Peter

An alternative that adds a really sleek look are these spark plug wires offered by Datsun Spirit. I've seen these on many cars and they're on my list. https://datsunspirit.com/shop/dsi-spark-plug-wires-2/ Peter

Steve and Robert, Thanks for the thorough description of the process. The engine from my 73 is being rebuilt at Datsun Spirit now, and after almost 42 years it seems prudent to rebuild the fuel pump too. If I understand correctly, I need a pump with 271070 on the lower casting. Correct? How do I know if the a pump has the dual layer diaphragm that you illustrate? Also, isn't it possible that the gaskets have dried out, or may tear when disassembling the NOS pump? Peter

I did this swap a few years ago and have this advice: 1) Disassemble the motor and clean the inside. Mine was full of dirt, grease and metal particles. 2) Make sure that your ducts have tight connections. I used black duct tape to seal the connections. Even after doing this, I really didn't get much of an increase in airflow. Perhaps my motor was worn, so I'd appreciate comments from others who've made this swap. Peter

I used Dynamat everywhere and added half-inch Dynapad on the floors and quarter-inch Dynaliner on the trans tunnel. These two additional steps made a huge difference in noise and heat reduction.

I bought Art's bracket for my 73 too. It's the perfect solution and I highly recommend it. Peter

Thanks Mitchell. This is a new driveshaft that I got from MSA but it won't hurt to check.

Coastal Man, Tell me a little more about your symptoms. Exactly what do I do with the driveshaft; I'm not sure that I completely understand. Peter

This is an R180 that I got from eBay last year. It was inspected and new seals were installed by Eiji at Datsun Spirit.

I'll check the exhaust. All six u-joints, including the driveshaft, have been changed. Didn't help!

Mixelplix, Your description sounds like what I'm experiencing. My symptoms start at 60 mph and increase with vehicle speed and I've been afraid to drive it over 70. If the gear backlash is adjusted is it likely that there will be gear whine or other noise caused by the worn ring and pinion?

Is there any way to check the diff without replacing it?

HR369 - the symptoms are related to vehicle speed, not engine speed. I can rev to redline in lower gears with no noise/resonance. Mark - I'll have to do more testing about this, but it certainly happens when the windows are up. Stanley - I suspected the driveshaft, so I replaced it with a new, balanced, one. Thanks for all your suggestions.

Dave C. Brake drums, u-joints, control arm bushings and shocks are new. Which body seams do you suggest taping?

Blue, it does seem to be wind related. Where are the bellows that you are referring to? The resonance is definitely coming from the rear of the car. Steve, I'm still running the diff mount + plus the R/T mount and had the snubber trimmed to allow a bit of movement. No change. The five speed is the close ratio model from an 82 ZX rebuilt by Eiji at Datsun Spirit. I found the diff on EBay and had Eiji inspect it and replace the seals. The mustache bar was relocated with there's no change.

It's not a mechanical sound, such as a bearing. Rather it's a low frequency vibration that only appears above 60 and gets worse. Perhaps something in the drivetrain that's out of alignment.

Hi all, For almost a year I've been trying to troubleshoot an odd acoustic resonance that starts about 60 mph and gets worse as vehicle (not engine) speed increases. By 70 mph it's scary, but below 60 mph there are no symptoms. I'm not referring to exhaust resonance, and it reminds me of the way my Audi sounds when the sunroof is open but the windows are closed. Initially I suspected the tires, but after replacement with new Michelin's and road force balancing (twice) I replaced the driveshaft, half-shaft u-joints and had everything checked (multiple times) by a local shop. All of the suspension, bushings, bearings, transmission and engine mounts are new. I also changed the urethane stop on my R/T mount after several suggested that the GM type that I originally used might be too tight. Late last fall the shop determined that the mustache bar had been installed backward, which was causing vibration to be transmitted to the the body. This seems like the solution, so I parked the car for the winter without checking further. Today was the first outing for the car, and the same symptoms are there. The car has a rebuilt 5 speed transmission and 3.9 R180 differential which were installed at about the same time that these symptoms appeared. However, since I rarely drive at higher speeds I don't know if either could be the source of the problem. It's definitely coming from the rear of the car. Any ideas? Peter

Julio, I'm glad that you're happy with your setup, but just for fun try this. Use your brakes moderately hard on a cool day, and then stop and touch the rear drums if your wheels allow access. If they're not hot, it would suggest that they are not contributing much. All cars depend primarily on the front brakes, but the rears are important too. Just a thought. Peter

Han, I would return the non-vented calipers and concentrate on optimizing the stock system. Premium slotted rotors, stainless brakes hoses, and your choice of high performance (not racing) pads should be a good start. Remember that you are dealing with 40 year old parts, and anything that is rebuilt is likely suspect. This is especially so for the calipers, so check out the link in my previous post. Also beware of aftermarket "performance" rear shoes. I was having rear brake problems and found that my aftermarket shoes were a full inch shorter on the leading edge that OEM! Stock Nissan parts are almost always a better choice, even though they may be more expensive. Your local dealer will probably give you a 20% discount if you ask nicely or are affiliated with a local Z club. After you've made some progress, post again with your results. We're always here to help. Peter

Han, I installed the Toyota non-vented calipers last year, with StopTech slotted rotors and Centric Posi Quiet ceramic pads that I got from tirerack.com. Stainless front hoses too. At the same time I installed the 15/16th master cylinder and had the rear brakes completely overhauled using Nissan shoes. Initially I was pleased and the ceramic pads have no dust or noise. However, on a spirited outing with the Northern VA Z Car Club I started to smell the fronts overheating. When we stopped I touched the rear drums (new) and they were barely warm! If you do enough research on this, you'll find that the problem is that this swap upsets the balance and the fronts are doing almost all of the braking. There is no easy way to fix this, and an adjustable proportioning valve is not the answer. The purpose of these are to reduce pressure to the rears, while an increase is really needed. Swapping to rear discs is a possible solution, but you'll find that many are dissatisfied with this because of the tuning necessary to find the proper balance. I'm not suggesting that the brake system can't be upgraded, but swapping parts without thorough research is unlikely to be satisfactory. One complication is the size of your wheels, which you didn't indicate. I have aftermarket 14" wheels that I really like. However even with the non-vented Toyota calipers I had the grind the calipers for clearance. The vented calipers will require spacers or larger wheels. Personally I'll be going back to the stock configuration, but will have the front calipers restored by PMB Performance. Others on this forum highly recommend this company but I have no experience with them myself. Hope this helps. Peter

Walter, I've had my Wesco belts installed for over a year, and they are a great upgrade. Occasionally the shoulder belt rides up a bit, which I could fix by raising the seat but so far that hasn't been worth the trouble. No passenger complaints either. Peter

No need to crawl under the car. Just unplug the relay in the passenger foot well. It will be the one that's warm when the engine is off.