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About Spades

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    Senior Member

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  • Location
    The Great Northwest
  • Cars
    '72 Z24 510 Wagon
  1. Spades

    Harmonic balancer for a naps z?

    This is what I suspect is happening. I am wondering if it is the way the cam was ground, because even adjusting the cam gear doesn't make it run "right"...and after exhausting any potential ignition issues (including testing for faulty distributors, coils, and plug wires (or running the wrong wire to the wrong cylinder)) what was left was the mystery grind cam. It does run good now, but again, the timing is advanced high for what these motors normally run.
  2. Spades

    Harmonic balancer for a naps z?

    The engine wants WAY more than 3 degrees timing. Already running the right plugs, both sets are firing, and this was all covered in a thread from a few years back (you and I hashed it over in great detail). http://community.ratsun.net/topic/33328-naps-z24-camshaft-issues/ Basically, after a ton of messing around, the cam gear was off time, but even with that reset, the engine ran the best at about 12 degrees advanced...15 degrees would give me more power (no predetonation or knock) but the engine would diesel if ambient air temps exceeded 90 degrees Fahrenheit. Both coils are functional and all plugs firing. I have swapped dizzys and control modules, checked mechanical and vacuum advance, cam timing, etc...and after tons of effort and placing it on the labscope and gas analyzer, it looks like it is the cam. Unlike most Naps engines, this one is still pulling strong at 5500 RPM...I haven't run her past 6k ever, but up to that point the power doesn't fall off. All of that brought be to believe the mystery grind cam from Oregon Cam Grinding is set up for high RPM dirt tracks or something, because this engine doesn't act like any other naps motor I have dealt with. EDIT: As far as the balancer, I am not really worried about it after doing a bit more research.
  3. Spades

    Harmonic balancer for a naps z?

    Yeah, if I go over 55 it dips into the secondary with the 4 speed...I haven't had the time to swap in the 240sx 5 speed i have sitting around...I don't even know if it will bolt up to the pickup naps z24 engine I have. As far as the partial throttle misfires, there is no EGR on this engine, it was never installed...the engine is a bored and balanced with forged pistons and rods (as well as the head ported and polished, and I did a mediocre/fair job at port matching the intake and exhaust manifolds) as the guy I bought it from was planning on adding a turbo to it someday. The partial throttle misfire was a random miss at 1/2 - 3/4 throttle at 3k-4k RPM under medium load...after mucking around with the cam and distributor timing, I dialed it out...but due to the insane amount of timing the engine likes and looking at all of the data I collected when first installing this engine, this cam is set up for either for boost or a high RPM oval track racer. At any rate, after looking at the labscope and gas analyzer readings at the shop I used to work at, I suspect that this engine would make more power and have better drivability with a different camshaft and a richer secondary jet (or an otherwise larger carburetor, I haven't seen the flow ratings, but I suspect the 32/36 might be a little undercarbed for a mildly built z24).
  4. Spades

    Harmonic balancer for a naps z?

    I have had interesting experiences tuning and setting the cam timing on this engine due to the mystery cam. When ignition and cam timing aren't dialed in perfectly, I have found the engine likes to have mid RPM partial throttle misfires, and after tracing the ignition system many times and putting the engine on a labscope, it appears to be from the grind of the "custom" OCG camshaft...so I always figured due to the extreme idle "lope" and the thing not wanting to run out of steam at 5500+ rpm, I figured the overlap and lift on this thing must be as crazy as they could go without the valves touching. All that being said, I figured that had a bit to do with the roughness of the engine, so I never worried about a balancer, but some people on other forums have mentioned that the NVH is possibly due to the lack of a harmonic balancer. At any rate, Doc510 said he had a used one, and I have seen oics of them on the internet. Right now I am not making it a huge priority cause it sounds like most didn't have them from the factory...and in my time working as a mechanic for 7 years I never saw a single one... EDIT: I still want to replace the mystery grind camshaft though...I never run the car hard, so it never sees the RPM this cam appears to be ground for. I also might see if I can re-jet the secondary on the 32/36 (or go bigger, though I hate to loose the fuel economy), the gas analyzer on the lab scope showed it would run slightly lean at WOT thru higher RPM ranges.
  5. Spades

    Harmonic balancer for a naps z?

    That's what I thought, but several people on forums had mentioned some issues with "welded on" flywheels and sheered crank noses that they blamed on a lack of harmonic balancers. The engine I have is not very smooth, and I blame the extreme OCG camshaft that is in it for the majority of the NVH, but I plan on ditching that cam for a Comp cams CCA-88-123-6. Anyway, Doc510 says he has a couple...I am guessing these things are the unicorn of NapsZ parts...not sure that 30+ year old rubber is going to do alot of dampening anyway.
  6. Spades

    Harmonic balancer for a naps z?

    So the NAPS Z motor I originally swapped into my wagon did not come with a balancer (just a standard crank pulley), and the Z24 long block that I later bought did not either. I just swapped all the pullys from the Z20 to the Z24 block when I built it (I had just bought all new stuff to stick on the z20 before it tanked about 60 miles later...go Bill's Datsun "remanufactured" engines). I have read in several places that when the balancers go bad it can cause all kinds of chaos, and none of my naps z's have had them, just the standard crank pulley. I have not been able to find anywhere that sells a new balancer. I am wondering if anyone knows where I can buy a new one (I am sure I can find a used one somewhere, but then the question is how well is that 30 year old rubber going to dampen vibration). If the worst I am going to be dealing with is the lack of refinement without the balancer, I could care less, but I really don't want to damage an engine with only a few hundred miles on it...so any input or suggestions are welcome. Thanks in advance!
  7. Hey everyone. I have been absent from the forums for quite some time (first due to serious health issues, then after that was sorted out I started working two jobs) and my wagon has been mostly parked (only taken out on sunny days to keep the lot rot monster at bay). I am wondering if any company or shop makes a direct bolt in lowering strut assembly package (no hacking, welding, or modification required) for the front of the 510? I put new struts and hacked a coil off the factory springs back when I built the car, but I would like to go a tad lower and unfortunately I am still working some crazy hours and I don't have the time to go crawling through junkyards for 280zx struts (or the time to hack them to suit the 510). EDIT: I did a fairly quick search (sorry if I missed anything) but I am not seeing a complete setup, and most places offering an upgraded coilover with better front brakes are requiring a 280zx core. So, if you have the money, but not the time, and want a better brake setup and a lower drop in the front, what are the options? Thanks, Spades
  8. Thanks for the tips mike! I had already dried out the dizzy and cleaned all my contacts, but I have not run a seperate ground yet. I will try that...it doesn't look like anyone local has a module, but I did get a PM from someone that is willing to ship a used one if the ground idea doesn't work.
  9. Well, I will try one last bump. If anyone close to Portland has a Z24 or Z22 8 plug distributor or ignition control module, please fire me a PM...I am hoping not to have to deal with shipping.
  10. Bump. Still looking for a local dizzy or ICM. If anyone around the portland area has one sitting in their garage, let me know!
  11. new cap and rotor as of when I parked it, tried swapping spares in when I cleaned up the inside of the dizzy. Distributor signal is dropping to the coils intermittently, even though I have constant power to the dizzy and coils...somewhere in the module it is cutting out....at least I think it is. I have test equipment hooked up, and no voltages are dropping, but even though everything has power, the ICM stops sending a signal to the coils and I loose spark. Normally that is hallmark for an ICM failure.
  12. I need an 8 plug distributor or ignition module from a Z24 or Z22 engine from 1982 through 1984 nissan pickup. I tarped up my wagon and parked her for the worst of the rain, and while everything stayed dry, the distributor apperantly had some condensation in it. Every time I untarped it and hooked up the battery to let her run, she had no problems, and I did not notice any issues until I went to drive her. I cleaned the distributor up, but every so often the ignition module is glitching out. Hopefully someone has a used nissan part lying around so I don't have to buy some overpriced chinese knock off. I would prefer someone local to the oregon area, I don't have the time off work to travel far or deal with shipping concerns. Shoot me a PM if you have something!
  13. hey! and crap, last night i was so tired i put this in the wrong section...my apoligies to the mod that has to move this :(
  14. I need an 8 plug distributor or ignition module from a Z24 or Z22 engine from 1982 through 1984 nissan pickup. My wagon was parked for the winter and even though I did everything I could to winterize it, I did not expect to get some condensation in the distributor. I cleaned the distributor up, but every so often the ignition module is glitching out. I would prefer someone local to the oregon area, I don't have time off work to travel far, and I hate dealing with shipping. PM me!
  15. will have to check the budget before i can say for sure that i will be there...not working until kid is back in school to avoid daycare costs. things are kinda tight right now.

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