kmack

Just out of curiosity, how could you measure a spring rate at home?

My engine info has been documented in the following thread: http://www.classiczcars.com/forums/showthread.php?s=&threadid=10733&highlight=dyno But here's a quick run-down: Original L24 block (1971) stock bore stock pistons new rings new seals new gaskets FelPro head gasket E31 head (unmodified) stock cam stock oil pump 6-2-1 headers into a 2-1/4" exhaust with turbo muffler '71 SU's w/ K&N filter in stock airbox stock needles and nozzles (currently sure what number needles are in there, but they are the ones that came with the car when I got it.) With the airbox in place, I pulled 136 hp at the wheels. I pulled 139.2 hp at the wheels with the airbox removed. And I was still running rich. Estimated compression is 9.5:1

2Many, I don't want to cut the coils if I don't have to. I'm just looking for pros and cons for this option. 1. Yes I already have adjustable bushings in the control arms, but you may remember that the initial reason I got them was to overcome the too much positive camber on the left front suspension. I have since slotted the strut tower on the left front to help make the bushings more effective for camber adjustment. 2. The MSA camber plates seem to be my best bet, but as always, they cost more money than I have. Cutting the springs effectively costs me nothing more than my time. It's the side effects that I'm trying to determine right now and if I want to deal with them. 3. Either way I want to lower the car some. Any other options on doing this other than: a) relocating/sectioning the strut tubes buying lowering springs (already have the money issue) c) buying larger rims to help fill in the space (again money issue) 4. If I could at least get to -2.5* of camber that would be great! But like I said, with bushings, and a slotted tower, I can only get -1* out of the left front. The right front will go farther, but there's no point if the left can't follow. I'd like to pursue greyghost's idea about the 710 control arms, if anybody has any more info. My other option (that I honestly haven't looked at much) is to lengthen my left control arm. I have already lengthened the left T/C rod to get my caster where it needs to be. That has worked out good so far. Or I could relocate the control arm holes in the cross member, but by how much? What dimension of movement of the holes gives what change of camber in degrees?

greyghost, Interesting idea here. Although I haven't seen many 710's around the junkyards lately. Any idea how much longer the control arms were in relation to Z control arms? Were the 710 control arms used on any other models?

Well....I never said anything about "dumb" questions....

What's the consensus on cutting a coil or two off the strut springs? I'm looking to lower the car some and add a little negative camber also. I have a set of performance springs that work pretty good on the track, but I can't get any more camber adjustment. (I need to get a little more for running high-speed events). I realize cutting the spring will lower the car some, not a bad thing, though. How will this affect the spring rate? Will it increase it some or at all? At this point, I don't have the budget for coil-overs, and standard camber plates are designed to be used with coil-overs. I know MSA has a set of camber plates to be used with stock struts, but I'm afraid that these add to the overall strut height some and won't give me the added negative camber I'm looking for. FWIW, I already have about 1-1/2* of negative camber. I'm looking for up to -3*. Any thoughts? Good or bad? I'm just in the idea stage right now.

Gee, thanks a lot Chris.....seeing that picture sent shivers down my back as I remembered rebuilding those damned boat-anchors so many years ago! :tapemouth :tapemouth :sick: :tapemouth To think, I actually had them working pretty good. Live and learn

The 260's originally came with flat tops. Here is a picture of the roundtops on my car: http://www.geocities.com/vintagericeracing/159.html Round-tops have the float bowls attached to the lower side of the main carb body. The flat-tops, have the float bowls integrated into the bottom of the carb body. Plus they are much bigger than the round-tops. And we all had to learn about these things at one point or another. Hell, I didn't know the difference in carbs until after I already had the flat-tops running on my old spare motor from a junk '73!! Talk about a waste of time!:tapemouth :stupid: No one here will criticize you for asking questions. That's how you learn. Before you know it, you'll be the one answering someone else's questions. We've all been there.

Engine ID number should start with: L24, L26 or L28 If you do have the "round-top" carbs on the engine, you're headed in the right direction. Round-top meaning that the transition from the horizontal top surface of the carb dome to the vertical side surface has a radius to it, not a sharp edge. For those reading that may not know.

And.....? Please continue this topic. I have an L28 waiting in the wings to become my 200hp engine, but if I can get it from the L24, then all the better. As it stands, I'm already pushing 139hp at the wheels with my original L24 w/ E31 head. That puts my crank output somewhere in the neighborhood of around 165 hp! How do I get more?

Here's my guess: Keep in mind this is subject to misinterpretation and my inability to put forth in words exactly what my brain thinks...:stupid: It looks like the adjust is there for one of two reasons (or both). 1) My first thought would be that placing the carb linkage in the farthest hole on the arm away from the manifold would give a slower throttle response. That in turn, would make it easier to make minor adjustments to throttle position using the gas pedal while driving. Basically, better throttle control. Putting the carb linkage in the hole in the arm closest to the manifold would give you quicker throttle response due to having a shorter distance to travel while opening the throttle butter-flys. Kind of a course vs. fine adjustment type of control. 2) My other thought would be to maybe help overcome some of the same type syptoms in the bell-crank set-up as with the stock Z throttle linkage issues at the firewall. But I think my 1st opinion above is a better reason. So tell me, did any of this make any sense at all? I know in my mind it did....

Almost 99.9% of my time while logged in, is from work. Strange as it seems, I tend to have much more free time at work than I do at home. Although I haven't been logged in as much lately as in previous years (new job in the last year), I still get on fairly regularly. I just have too many projects at home to tend to, and the computer at home is WAY to slow!!

I'll also agree with everyone here and say paint it what you wish. My personal opinion, though, is this: The early Z's are one of the few cars that can pull off a yellow paint job and still look great!! Not even Corvettes look as good in yellow as a Z! Something about the body... My '71 is Nissan 905 Red (like a Cherry Red). I went back to the original color for a variety of reasons. The PO had repainted the car similar to Will's, it was painted Porsche Guard's Red (slightly darker) when I got it. The paint was bad and had to be completely stripped off the car. Now this left me open to paint what ever color I wanted. And I REALLY wanted it to be black! But, I'm also a bit of a perfectionist at heart. And to change the color in my book, meant changing the color inside and out. Exterior and interior, floor and door jambs, everything. That ended up to be much more work than I wanted to do, not to mention more paint. I then found out that the 905 Red was much brighter, so I went for it. That color, on top of a very light-colored primer, absolutely glows in the sun! So much that on a bright, sunny day, you cannot stare at the car unless you're wearing sunglasses!! So my recomendation? Paint it what you like. But keep in mind, that if you change the color, and don't change it completely, you will, at some point, still be able to see the yellow later on. The choice you make ultimately depends on what you want to do with the car and what you want the car to be for you. BTW - Nissan Sunset Orange (350Z) looks great on the early body Z's!!!

This was also discussed a few years back, but I think on the email list... Some Ford cars and trucks run an impact cut-off switch. Particularly, Ford Escorts and Ranger pick ups, are the ones I know for sure. If the vehicle was ever in an accident, the impact would trigger the switch closed and cut power to the fuel pump. The fuel pump would not get power until the reset button on the switch was pushed. Escorts had the switch located in the rear usually behind the rear quarter interior panels (Left side I believe). The Ranger pick ups had them mounted under the dash (center) right about where the carpet terminated at the bottom of the dash board. Simple to install really, you just wire it in before the fuel pump and place it in a place where it can be accessed if you ever hit anything. Which hopefully, will never happen. As for the oil pressure switch, I can see one benefit. If you ever lose oil pressure while driving, either because you burned all the oil up and never checked it or the oil change service place forgot to put the drain plug in tight, then theorectically, the engine will die and keep you from going any further without oil.

I love it when I diagnose something correctly! :classic: Mark, glad you got it figured out and that your car is now running. Now finish tuning the carbs and the motor and go for a well deserved drive!

Yes, double check your timing, inspect your plug wires, and points. Make sure everything is up to snuff. Process of elimination....

SU's don't use an accelerator pump.

Yeah, I know. I feel so used!

Oh, and did I mention that I have a "depression" (read: BIG missing chunk of skin) on my left forearm? After I got done painting my car, I had lots of overspray on the floor. Found out that a sanding pad on my 4-1/2" grinder took the paint off the concrete really nicely. Well, with grinder in my right hand, I used my left hand to "flip" the power cord out of my way. I flipped it over and across my right hand. (See where this is going?) :stupid: Needless to say, skin will not stop a fast spinning grinder, but it tries.... :tapemouth :tapemouth Now my wife pulls out my arm to show others and says, "This is what happens when you spill paint in my garage!"

Was this car running before you rebuilt the carbs or was it sitting? Were you getting fuel before? Got to check it out step by step. Use a separate gas can like you were using (2.5 gal will work just fine). Start at the fuel pump and go fromt here. Check each and every item between the pump and the carbs. You'll eventually find the blockage through process of elimination. Good luck and let know how it turns out.

I assume the car does not run since you say it's in a pasture. Bad sign number one. A bent hatch is bad sign number two. Biggest things to look for are rust, rust and more rust. Do a couple searches here and you'll find hundreds of thread describing what to look for and what to avoid. A couple things mechanical-wise to think about. A good 280Z (good body and mechanically sound) usually runs for somewhere between $2500-4000 here in Texas. (Calm down guys, I said Good, not great) If this car has been sitting, you can be gauranteed the fuel will be bad, possible rust in the gas tank, fuel lines will be bad, injector lines will be bad, water hoses will be bad, rubber brake lines will need to be replaced, injectors may be sticking or not working, or worst-case, the motor might be frozen. The wiring may also have problems. Body work is expensive enough, but all the little items you'll need just to get the motor running and the car safe for the street can eat your budget up before you realize it. I'm not trying to deter you away from this car in anyway. Just keep in mind, you are looking at a vehicle that may need almost a full restoration to be driven safely. That can get expensive. I would dig into this vehicle more and find out all you can about what it might need, if the owner will allow it. At this point, and based on your limit description of the vehicle, I wouldn't pay more than just a few hundred dollars for it.

Check your float level. If the carbs and everything else was working fine before you rebuilt them, then maybe you inadvertantly adjusted the float level so that the float valves are staying closed and not letting fuel in. You did say that you removed the floats and added gas and the car ran. Was there gas in the float bowls when you first opened them? Try this: Disconnect the small rubber line between the fuel pump and the fuel rail. Does gas flow? If yes, continue to next step. If no, Fuel pump. Now disconnect the fuel lines from the fuel rail to the carb float bowls. Both of them. Does gas flow? If yes, then continue. If no, blockage in fuel rail. Disconnect fuel lines between float bowl and choke nozzle (bottom of carb.). Does gas flow? If yes, possible blockage in nozzle. If no, float is sticking or staying closed. You have to be methodical in the process. Go step by step, section by section. And ONLY change one thing at a time! My guess right now is that it's in your floats. But if you follow these steps, you'll find it. It's definitely fuel related so at least you only have one system to check! :classic:

Stephen is right. My apologies, Steve. I felt a personal attack there. But I still stand by my comments (in general).

I had the same anxiety about the SU's also. But they really are easy once you understand them. And they're not hard to understand. They work off the simplest principles of carburetor theory! If you can understand how a simple caruretor works, you're set! I've had people at race events ask me how hard it is to tune my sidedrafts. They are amazed (and usually don't believe me) when I tell them it takes less than 15 minutes, with no special tools (other than my flow meter).