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DHale_510

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About DHale_510

  • Rank
    Newbie
  • Birthday 09/06/1947

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  • Gender
    Male
  • Location
    Nampa, Idaho
  • Cars
    11 Datsuns; 8 510s, 2 Zs, 1 1200

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  1. I have them every week when I go to mu garage and look around at the 8 Datsuns there. I could then go over to Kim Blough's across town and see about 150 Z cars if I wanted. we don't need to babysit any "rebels" in a car show either. Dennis in Idaho
  2. I ran backups with Rockwell's chassis dyno to Rebello's engine dyno back in the day. Several motors, Pinkie's 217hp 1800 and Bluebird's 285hp V8, but never an ITC nor my ITS Z motor. They agreed. The 15hp statement seemed to come out of the midnight MOFO meadows BS sessions at Shasta. I was never able to find anyone that could backup the MOFO meadows claims, nor even anyone that tried. It seems the northwest water has odd effects sometimes.... Dennis
  3. Points to add.... 1, The stiffer Roadster front springs were the competition ones. They were never common and are greatly over rated. The normal Roadster front springs are basically the same as the 510 rear springs. 2. The arithmetic for calculating stiffness looks hard, but since when cutting the springs you aren't changing the wire diameter nor coil diameter, only the length of the wire, you may just do a simple ratio calculation. If you cut one coil from 10 coils you are 10% stiffer. 3. Changing wire thickness gains stiffness more than you think. That's the D cubed part of the equation. Pretty much each gauge of wire is triple the previous gauge. That's why the old Dodge mini truck and aero Tbird front springs work for the back. 4. While the cut springs are shorter and stiffer, the total load capacity is reduced and the car runs out of suspension creating lots of problems and often is considered too stiff but is really just crashing into its stops. 5. If you want to lower the car by half of it's suspension travel, you want to double the spring rate, maybe more if you want to increase to transition handling. Usually these goals are in common. 6. Lowering the rear of a 510 by 2" changes the rear toe alignment by 1/4" or more. Toe out not toe in. This is bad unless you really like steering a shopping cart at 60mph. This is not adjustable with factory parts. It is not obvious by looking at the car, but if your camber is visibly changed you can bet the toe out is there too. 7. Easily adjustable rear coil over conversions are great for playing with different spring rates and terrible for accidentally getting the rear toe settings all screwed up. the lower mounts at the control arms are not strong enough for the load either. So, for a quick and cheap handling improvement, stiffer springs that do not lower the rear are the best deal. Stiffer front springs with shorter '69 or 280ZX front springs are also the cheap and effective solution. Stock wheel rates on the 510 are about 90#/" all around and the balance is so good we all became interested in the car. You probably want to keep that ratio rather than become a chassis engineer and "improve" that. The rear suspension leverage is almost 4:1 spring rate to wheel rate while the front is almost 1:1. I hope the helps.. Dennis
  4. Also the distributors will wear out. The vacuum advance plates are particularly prone to sticking, so the actual advance can vary widely, causing very carburetor fault like effects. You can wiggle it by hand to see if it sticks or you can look at the timing with a light. All the movements need to be smooth. The L20b is more timing sensitive than the smaller motors, I found that knock occurred first at 5000 rpm, far above the audible range for "ping". It also liked much slower advance curves than the stock distributors were set for, so there was power in re-curving to a slower rate, otherwise you just have to live with retarded maximum timing settings, like 22* maximum, which is optimum at the 3500rpm or so that the distributor maxes out at. That overadvanced ignition may feel like a misfire or stutter. It is a bad thing. Dennis
  5. The 280ZX rear shocks also hold the springs. They have much larger and stronger mounts than a 510, and they are longer. I guess it really depends on how much fabrication you want to do, but they are not a simple fit. Dennis
  6. I have had brake hoses that deteriorate internally and act as sort of a check valve to cause this problem. Dennis
  7. Back in the day my buddy and I hopped up a few BMC A series motors in a Sprite. We never supercharged one, but did manage to double the power with a little help from Mr DeLong and adding compression and so on. Lifetimes of the motors was dramatically reduced, like about a year of street driving. Others did try the Judson superchargers with almost identical power gains and durability losses. Then we started using bigger engines to the same power with greater durability. My favorite combination was a Datsun R16 roadster motor in a Bugeye Sprite. It was a bolt in after the heater was removed. BMC mounts were interchangeable. Now I would consider a R20 forklift conversion.... I think some guys have replaced their J motors with A13 and A15 motors. Still really old and authentic with less cost, more power, and real durability. The last NOS Judson I saw was asking about $1500 and that was years ago. Maybe a Torquestorm or such could be made to fit but it hardly fits the '50s look. Dennis
  8. Yes I have had this problem. It was apparently caused by a strut insert that was a bit short. I "shimmed" the assembly with a couple of washers so a full thread or more was visible at the nut and never had it happen again. I presume that the strut insert was hammering" the nut a bit like an impact wrench. Dennis
  9. I have run 300hp in a welded up one without trouble with the differential. The rest of the package was trouble though. I have run over 200.000 miles, about 1/3 on track, on a factory LSD one without trouble. I have run over 500K miles on a stock one behind a 100hp L 16 with mostly sticky tires. Any tire you can put under a 510 fender will not overstress a R160. A LSD will more than double the strength of a R160. Welding one is not a LSD and likely will shorten its life. Maybe the question is vague, maybe a R160 is pretty strong. Dennis
  10. The attraction of the RX7 differential is usually the clutch LSD, disc brakes, and the 4 x 4 1/2" bolt pattern. Unfortunately few RX7s came with these. The relatively rare '85 and '86 GSLSE models were the only ones like this. They were coil sprung instead of leaf sprung so all the mounts are different. and they were wider wheel base than the older Datsuns. They are not really bargain garage find parts, but they work very well is you can adapt them. I think all the 620s had 6 bolt wheels so not even that part works. Dennis
  11. Gokarts and formula open wheel type racecars owe much of their immediate steering feel to light weight and roll centers at the same point as their center of gravities. They do not lean before turning. I doubt you can achieve either with a 510, I've certainly tried but only gotten close. But then neither of those have our wonderful lift throttle oversteer to enjoy. Sometimes it all equalizes out.... Dennis
  12. DHale_510

    V8 swap

    Another way of looking at the cooling problem is air flow. The stock radiator and mounting has good airflow for about 100 hp. Your V8 is about three times this, so it needs about three times as much radiator AND three times as much air flow. The grille area is not likely big enough for this, and you can not cut away so much that the front suspension gets weak. so the seemingly silly in the bed [or even roof] option starts to make sense. Otherwise either lots of airflow boosting fans [mechanical ones almost always move more air than electrical ones] or very special aerodynamic tricks like fancy race cars use. Dennis
  13. DHale_510

    Mikuni vs Weber

    The installed venturis are more relevant then the Mikuni vs weber question. It is usually best on a street car to have slightly smaller venturis than intake valves. You get the widest power band this way. I have also found the Webers tune easier on smaller motors, Mikunis on larger ones, and the Mikunis have fewer expensive parts to tune, but are harder to find. Usually the Mikuni manifolds have better throttle linkage than Canons. SUs are always easier and cheaper, generally work fine once set and not fiddled with. Webers are pretty much the opposite. Dennis
  14. Now he needs to understand that the lash pads come in many thicknesses and are critical to the assembly. They need to allow a centered wipe pattern on the rocker to keep them from cutting into the cam. They change with a reground cam, resurfaced rockers [this avoids the mismatched confusion trouble], reset valve seats, replaced valves, resurfaced heads, and maybe just wear. The poster started with a problem of a missing lash pad and these problems were never addressed. If your machine shop doesn't understand lash pads and thinks the threaded adjuster is there to make all of these adjustments [like Chevy], you need another machine shop that knows Datsuns and Mercedes. Stoffergren maybe knows this better than anyone else on this list. He has setup several heads for me in the past. Trust him. Dennis
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