Jump to content


  • Content Count

  • Joined

  • Last visited

Community Reputation

1 Neutral

About SuperDave

  • Rank
    Registered User


  • Map Location
    Decatur, GA
  • Occupation
    Software Engineer

My Cars

  • About my Cars
    240Z(2), 260Z(ugh)

Social Sites

  • Website

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. One of the ugliest jobs I've done while stripping down an old 240Z has been removing the tar-like insulation that covers much of the interior floorboards and transmission tunnel. I have done it by using aircraft paint stripper, but this was a big mess. It softened up the tar, but made it flow into low spots. Once I had most of it removed with a paint scraper, I had to use a wire wheel and more paint stripper to get the last of it off. Some have suggested using heat, but I'd think this would also be a mess. There must be a better way. Actually, I found that with no chemicals at all, some of the insulation will come off quite easily. Just get the corner of a paint scraper under it and it flakes right up and breaks off. That's the good news. The bad news is that, unfortunately, these pieces come off easily because of what's underneath--rust! The insulation that covers clean metal doesn't want to budge. A few years ago, a fellow racer had said that dry ice was the best way to clean off this insulation. I saw it mentioned a couple of other places on the internet, but I couldn't find any articles about it. Armed with just a few instructions of how to do it, I decided to give it a try. I would try to use dry ice to remove the insulation tar in the rear hatch/ trunk area of the old 240Z. Getting the dry ice was easier than I thought. My local Kroger stocks it for 99-cents a pound. They broke open a ten pound bag to sell me 5 pounds. I brought it home and tried to break it up into as small chunks as I could. Then I simply spread it on top of the insulation tar. All the areas I treated were level. I don't know what is the best way to apply the dry ice to vertical areas like a transmission tunnel. I got a really good feeling about this process when, before I was finished spreading the dry ice, I could hear cracking sounds where the dry ice had been sitting for a few minutes. Due to the cold, the tar must have been shrinking faster than the metal and finally becoming separated from it! Once I had spread out the dry ice as best I could and broken it into as small chunks as seemed reasonable, I went inside to watch the finish of the Daytona 500 and to eat supper. I came out about two hours later. All the dry ice had melted (had become CO2 gas and sunk invisibly to the floor and out of the garage). I started attacking with my paint scraper. Now, with minimal effort, chucks of the insulation as big as 3-by-9-inchs broke right off. In just a couple of minutes I had removed almost all of the insulation tar. The bad news is that I found some really nasty rusty areas that I wasn't aware of. But they will be fairly easily repaired. I'm glad I know about them. I did not try one technique that I had read about elsewhere--to use a hammer to strike the insulation. It is supposed to just shatter like glass. I was afraid this would leave dents in the underlying metal. And, if I remember it correctly, you're supposed to strike it when it's still cold (and mine wasn't really dry-ice-cold when I tried to remove it). I didn't get every bit of the insulation. I think there were some spots where I didn't spread the dry ice thoroughly enough, so I guess the insulation didn't get cold enough. So it looks like I'll go back in a few days and repeat the process on those spots. This was an incredibly effective and simple process and I will highly recommend it to anyone who wants to remove this material from any type of vehicle. It didn't involve any nasty chemicals, and didn't leave anything to clean up. Obviously there are precautions to take--I used leather gloves to handle the ice. It gives off CO2 gas, so make sure you have some fresh air to breathe. Other precautions will usually be listed on the package of your dry ice.
  2. There's one in every bunch. Ever heard of the Grassroots Motorsports $2000 challenge?
  3. Thanks, but remember I'm trying to do this cheap. I'm trying to find something in a junk yard that approximates my needs. I'm assuming that getting custom springs made will cost just as much as the coil-over kits.
  4. OK, first, let's just get this out of the way: Everyone repeat after me. "If you don't want to spend the money, you have no business racing." Right. I don't want to spend four figures on suspension if I can avoid it. I'd like to find a way to get springs in the 400-350 pound range and stay with the stock struts and mounts. By playing with the spring rate calculator at http://www.proshocks.com/calcs/coilsprate.htm, it seems that I only need slightly thicker springs. 0.637" in the front would give me 400# and 0.618 in the rear would give me 350#. Compare that to the stock spring thicknesses of about 0.417" and 0.448" Great. Actually, if you got springs of about the same length as the Zed and with 10 coils, you might want to start with just 0.605" in the front and 0.588" in the rear and cut two coils off to lower the car. Now, where to find these springs? I read somewhere that the Jeep Grand Cherokee uses 4.5" springs like the Zed, but I haven't been able to verify that. And, of course, I have no idea what the rates are going to be for that vehicle. Any ideas? (Other than putting $1500 on the credit card for coilovers and one of the admittedly nice kits.)
  5. Not that I'm as expert as the others who have replied, but (when has that stopped me before)... Since you already have 350# springs on the front, and stiffer rear springs is one of the things that will help understeer, 285# springs would get you to SpudZ's 350-285 ARRC-winning spring rates. You might think about getting some of the eccentric rear control arm bushings that would let you adjust your rear toe-in, which could also help your back end turn some. PS - I'm about to get ready to prep and paint my ITS 240Z project and I'm thinking about painting it LIME GREEN much like yours.
  6. I'm not writing this to say you're wrong, but I went out and measured the springs on my '72 240Z and used the calculator at http://www.proshocks.com/calcs/coilsprate.htm to callculate the spring rates: LF: 0.4174" (thickness) x 4.5" (outside diameter) x 10 (active coils) = 62.7# RF: 0.4167" x 4.5" x 10 = 62.2# LR: 0.4481" x 4.5" x 10 = 85.2# RR: 0.4555" x 4.5" x 10 = 91.4# I had read somewhere that the left front is a little longer than the right front, but that shouldn't affect the rates, just the ride height I guess. FWIW, I have a set of 2" lowering springs on my old 260Z that's currently up on blocks at mom's. I'll measure them this weekend and let you know.
  7. SuperDave

    z bodies

    If the yellow turn signal lamps are on the corners below the bumper, same as a 240Z, then you have an early 74. If the turn signal lamps are up in the radiator opening like a 280Z's, you have a late 74.
  8. Sorry, mate (Are Yanks allowed to say that?). I'm pretty sure you'll have to pull the stub axles out--or at least part of the way out. I did this recently and the only way to go is to use a shop press--don't bother trying to bang on them.
  9. Thanks for the input. This sounds just a bit more complicated than I want to try. Especially the heating up and cooling down stuff. Also, I noticed, when getting an emissions test last week, that my local full-service gas station had a shop press. I toyed with the idea of taking them to these guys, who are friendly but I don't know how expert they are. So for this job I will stick with my trusted and proven professionals and make the 15 minute drive a lunch to drop off and pick up the pistons/pins/rods from my machine shop. Fortunately, I have a lot of time.
  10. I've rebuilt Z engines a couple of times now. I have a new set of pistons and am about to begin prepping, polishing, and balancing the various parts. When it's time to press pistons back onto the rods, I've always taken them to a machine shop to get the job done. I'm thinking about doing this myself this time. I have access to a shop press, but I don't know much about what tricks might be involved in pressing the pins into the pistons. How many of you have done this step? How many of you have screwed up this step? Dave
  11. Thanks for the info. White powderly finish? Hmmm. Maybe there is a final bath they give it. Or maybe they blast it with baking soda or something. Would you care to TASTE your car and give me a report?
  12. When I finish de-rusting my pieces and parts, I always have to clean them off with a soapy brush, dry them, and run a wire brush over them. The electrolytic process leaves a black substance that will turn to rust if you don't clean it off. I was wondering what, if anything, they used on your complete car to clean it up. Below is one of my latest pieces (after I cleaned it up and ready for a coat of primer), a rear control arm. <br> <img src="http://www.davesweb.com/houndawg/images/P1030675_640x480.jpg" width="640" height="480">
  13. I can't believe I didn't think of using a drum! That should de-rust your part on all sides at once! Have you eaten through a drum yet? You should eventually. Can you post some pictures?
  14. This weekend I saw a high school classmate of mine who has a 280Z that he has owned for 20 years and 5 of his 7 children have used as a daily driver. He told me the car has 650,000 miles on it with only one valve job in its history. Simply amazing! Can anyone top that?
  • Create New...

Important Information

By using this site, you agree to our Terms of Use. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.