240ZMan

BTW, I had the same issue with getting the threads started on the endlinks. I put the wheels back on and set the car down on some "drive on ramps" to compress the suspension and still be able to get under the car. The suspension pieces were more level and that made the difference. Worked on the front end too.

You didn't say whether you had drums or discs in the back, but on my 73 when I swapped to 240sx calipers in the rear I swapped the cables between sides (left went to right and vice versa) and that allowed the cables to align without rubbing. You might see if that will help. But if that doesn't help, take some heater hose and slit it like you said and attach with nylon cable ties. I did that where my rear SS brake hoses come near the struts (used fuel hose since brake lines are smaller diameter) and all is well after 2 years.

Wow, I don't think there is any one answer to that question. Many people use the stock L24 with SUs as a DD and find it fun to drive and reasonably fuel efficient. As you go to bigger carbs and/or bigger cams, fuel economy is going to suffer, which I think would be a problem for a DD. Plus the power curve tends to shift towards higher rpm which isn't all that fun in stop/go traffic.Converting to FI, especially megasquirt which you can tune yourself, could make a significant improvement in mileage, but isn't cheap to do, and takes skills that not everyone has. For me, an L28 + mild cam with megasquirt, header/exhaust and a good 5 speed/diff combination would be a reasonable compromise for a DD that's fuel efficient and also a lot of fun to drive. Or use the stock SUs if you prefer and trade off some fuel economy.

I've read there's a nasty harmonic at 7500 rpm that will eventually destroy the crank if you don't properly prepare it, so for a stock bottom end it's probably something a little south of that.

When I first had my 73 240z I had the impression that the 2.4l somehow would "rev better" than an L28. If someone had pressed me, I suppose I would have pointed to the shorter stroke. If asked today which to choose, I would say L28 unless you a) you feel you want to keep the same block that came with the car, or you intend to compete and the rules require you to stay with the L24. Otherwise, if your desire is to make more power, then there's no reason to not switch to the L28 assuming you can get a block for a reasonable price, which is usually the case. As for how fast it revs, the flywheel weight, choice of pistons, tuning of the fuel delivery system etc will all have a major impact on that as well. My sense without having done any side by side testing is that a well sorted L24 and L28 will both have the same responsiveness to throttle inputs and both can be made to rev to levels beyond what most of us could live with on the street. With a streetable cam that doesn't run above 7k rpm I can't imagine that an L24 has any significant advantage over an L28. I'd choose your option C, just watch the compression ratio if you plan to use flat top pistons. I'm running that combination with a reground cam (284/284 with .480" lift) and have to back the timing to no more than 24 degrees advance to avoid detonation, even with premium fuel. Perhaps you have better "premium" where you are, but I'm guessing you still won't be able to run full advance. If you don't already have the head you might look for a P90/P79 and shave it.

Hey, good for you, hope it holds. Still I would suggest that the next time you order from MSA or Courtesy Nissan (and with an older Z, it's "when" ) that you order replacements. They're cheap (cost less than shipping) and as you now know, not hard to change. Compared to the alternative of the delightful smell of gear oil in the cabin AND cleaning it up, it's a worthwhile investment.

There's an O ring on the outside which is easy to see. There is also a seal inside the speedo collar that you might not see if you don't go looking for it. If it's leaking you may find gear oil under your dash. Ask me how I know...

The pump pulled down to around -20, but that was at 6500 feet elevation. If I'm doing the math right, at that elevation about 6 in. Hg has been lost. So that would suggest it came close to the 28.3 target.

I'll add another thing to consider: what cam are you using? The stock cam provides good torque down low but starts to decline by 4500 and is falling off pretty rapidly after 5500. If you were using that with the later 5 speed (81-83) and a 4.11 diff, I think you'd find that you would need to shift too soon. I think that a 3.54 diff and late 5 speed is an excellent combination with the stock cam. You might consider a 3.7, but you'll be upshifting at lower speeds than you currently do with the stock 4 speed. You mentioned that you plan to swap to a 3.9 or 4.11 diff later, and with a cam where the power/torque peaks are higher up this is a very nice combination. In fact, a bigger cam with a 3.36 or 3.54 diff wouldn't be much fun at low revs since there's less torque than stock. The idea is to get up into the power band as soon as possible and then stay there when you shift to the next gear. As suggested above, the Transmission Calculator site http://www.geocities.com/z_design_studio/transmission.html let's you simulate any combination of transmission, diff, and tire size and see both what the max speed is in each gear, and also what your cruising rpm would be at any speed in any gear. I found it very helpful when planning my swap to pick a few typical speeds that I drive a lot (70 on the freeway, 35 and 45 on secondary roads) and compare what the revs would be with what I already had. I really like the combination of late 5 speed, 4.11 and larger cam but it wouldn't be for everyone, especially for those who like to keep the revs low and not shift a lot.

It worked "ok". I'll guess that your self-contained unit pulled a better vacuum, but at $10, the price was right for me given that I will (hopefully) only use it once.

Thanks Steve, since I posted I did pull a vacuum and then loaded the Freeze 12. It's working reasonably well given the limitations of the dealer-installed system. I just want an AC system that will take the edge off the heat of the day on the freeway when it's too loud to have the windows open. The system is up to that, but not much more at this time of year when it's 95+.

I should have been more clear. If you normalize the ratios using 3rd as a baseline, then you see that for the 4 speed 1st is 2.50 times 3rd, and 2nd is 1.55 times 3rd. For the early 5 speed, 1st is 2.54 times 3rd and 2nd is 1.59 times 3rd. In other words, on a relative basis, 1st, 2nd and 3rd gears are all the same (within a small tolerance) for those two transmissions. If you were to swap the early 5 speed and leave the 3.36 diff, then 1st, 2nd, and 3rd would all provide slower acceleration than with the 4 speed. If you were to swap the diff to 3.54 at the same time, then 1st - 3rd would be almost the same as before. You would still have a relatively large change in ratio going from 2nd to 3rd. The later 5 speed has 3rd gear closer to 2nd which was the point Darrel and I were originally making. Perhaps these 2 screen shots from the transmission calculator will make it more clear. Note that the max speed in the first 3 gears is nearly the same for both combinations.

FWIW, I found mine in as the front diff of a nissan 720 (pickup) 4x4.

Like Darrel said, the gap from 2nd to 3rd is too big in my opinion with the early 5 speeds. (The first 4 gears are the same as the 4 speed if that gives you a point of reference.) I'm sure you're hoping to hear that it's a reasonable compromise, but I'd send it back and wait until I could find what I wanted. BTW, a late 5 speed with 4.11 diff is a sweet combination. I couldn't be happier with that combination both on the street and on the track.

74 was the first year that the factory installed a rear sway bar in the US. But some 73s had the brackets (mine built in 2/73 had them). Before that it was a front bar only, 5/8" IIRC. For me, I did the bars before springs and struts and they made a huge difference. Some people like a softer ride, and for them bigger bars and softer springs/struts is an option. I'd suggest you first do the springs/struts since it sounds like you've already decided to do that. You can then see if you feel you want to increase your roll stiffness further via adding/upgrading bars. Keep in mind that every improvement for handling will bring some tradeoff. I have the Ilumina adjustable struts and on their softest setting I'd say they are similar to the tokico blues. But on their stiffer settings (they go 1-5), the car gets very bouncy and almost nervous. It's really not fun at all to drive on the street like that, but on the track the way they limit body movement further is appreciated, especially on bumpy high speed sweepers. My point is that there's no one setup that will be best for all conditions. You'll have to decide how much you want to trade off improving the handling vs. degrading the ride.

Randy, do let us know how it affects the handling and if the rear gets loose on you. I really don't think it will if everything else is stock, but better to find out when you're ready for it.

Question for the original poster: what size is your front bar? Is it the original stock one? I ask because the bar in the picture looks reasonably beefy and I'll guess it's at least 5/8" which was the size of the stock front bar IIRC. My point is that you're going to significantly change the roll stiffness of the rear. It might be a good idea to take it out to some empty space like a parking lot on a sunday morning and try a few quick side to side transitions while accelerating and also while braking just to be sure that you haven't made the rear end excessively loose. I don't think you will, but it would be a good idea to find out all by yourself in a safe place instead of out on the road in a panic situation. Also, if yours is a daily driver, you should try it out in the rain (less grip) to make sure nothing evil is going on. :eek: Mine is no longer fun nor safe in the rain with the changes I've made. But then again, it's just a fun weekend car now so I just don't drive it when it's wet.

Thanks Stephen, that's just the advice I was looking for. I do have another question. After swapping in the "new" compressor from the JY I added the lube from the ebay Freeze 12 kit, and then added about 2 1/2 cans of the refrigerant. I used the old skool method of adding until I didn't see any more bubbles in the drier (I didn't have the manifold gauges at that time). My goal was to just get the system up and running and verify no leaks. Also, I didn't know to invert the can which I now understand is important to keep get a proper mix of the Freeze 12 components loaded into the system. Now I'm wondering if it's worth starting over by pulling a vacuum, and then adding with the can inverted. I would need to pick up a vacuum pump cheap. Is this HF unit worthy? http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96677 I'm sure it's not great, but is it good enough? And is it worth doing this over? The cooling is marginal on a good day, so I figure any improvement probably does make it worth while.

I'm running the dealer installed AC on my 73 with a 81-83 compressor and Freeze 12 refrigerant. I recently picked up a Harbor Freight AC manifold gauge set http://www.harborfreight.com/cpi/cta...emnumber=92649 and need to know the specs for pressure on both sides when the system is filled properly. I've searched using just about every combination of words I can think of, but so far nothing. Can anyone help me out? Also, assuming I need to add some more refrigerant, what is the proper procedure to do that? The manifold has a fitting to allow this, but is there a specific sequence? And just to confirm, is it added to the low pressure side? Any other words of advice and/or cautions from those who know AC systems? I know the theory of how they operate, but am without much practical knowledge.

Ever since I used a wheel cleaner that is acidic, I've begun to get corrosion on the outside of calipers, at least the toyota 4x4s up front. (I stopped using it, but unsurprisingly the rust remains.) I figure this is a good excuse to paint them so picked up a caliper paint kit from the local part store. But I'm wondering what's the best way to remove the rust prior to painting? I am going to unbolt the calipers and remove the pads, but don't want to remove the brake lines if I can help it, so whatever I use has to be something that can be used with the car up on stands in the garage. (for example: rinsing with huge amounts of water won't be an option.) What do the brake painting gurus suggest?

You should check the head for flatness before you put it back on. If it is warped, you'll be doing this job again much too soon. If you don't have a flat bar, take it to a machine shop. It's pretty easy to check and they can do it while you wait. If it is tweaked a little (not uncommon for these heads), they can do a mild shave to clean it up.

There are others on this forum who know the details of what was offered each year far better than I, but I can share my experience with my 73 and hope that it gives you some insight. My 73 (build date 2/73) had the dealer installed kit. As sblake01 says, it had an upright compressor mounted on the passenger side, although it did have the mechanical fuel pump as well so not sure what's different on the 74. In any event, the mounting bracket looked like it was designed by Rube Goldberg so I swapped to a later compressor and bracket from an '80 280zx. It mounted on the driver side and bolted right up - I just had to get a new hose made. From what I've read and experienced, the later compressors, while not as good as modern ones, are still better than the original one from the dealer kit (less vibration, slightly more efficient). I picked mine up at a JY for $20 so they're not expensive if you can find one. Ordering online and shipping would likely change that though. There is a small panel with a knob for the temp control that is mounted under the dash just to the left of the center console. The control has a thick wire that goes to the thermocouple that sits in between the fins of the evaporator in the box under the passenger side of the dash. In order to run the AC, all 3 sliders are moved to the left which effectively closes the HVAC system to outside air. The knob on the controller is turned to the right to set the temperature. The system works reasonably well with good airflow over the condenser - in other words, on the highway. Again, I don't know how much of this is relevant to your 74, but maybe it gives you a place to start.

Hi Mike, I think we met a the ZCCC meeting the other week... I had DGVs a few years ago and I'll paste from my notes the setup I used - fyi my house is at 6300 ft so quite similar to you. - Primary main jet: 1.40 mm - Secondary main jet: 1.35 mm - Primary air corrector: 1.65 mm - Secondary air corrector: 1.60 mm - Primary idle jet: .55 mm - Secondary idle jet: .50 mm - Primary emulsion tube: F50 - Secondary emulsion tube: F6 - Pump jet: .50 mm My setup ran just as well as SUs - not better, not worse. Given I've moved on to FI I'll try not fall into the old tastes great/less filling debate between SUs and DGVs. Suffice to say that when properly set up, both are good carbs and will easily meet the needs of a stock Z. I'll guess that the current setup is running very rich. Given it's not much work to change the jets, I'd try the smaller set. They're still bigger than I ran, but see how it does. Another FYI, I bought mine used as well, and when I tore them down for the rebuild found that the jets and air correctors were all mixed up. For example, on one carb the primaries and secondaries were interchanged. If you haven't already done so, it's worth going over them in detail to make sure they're assembled correctly. Good luck! PS. Don't forget the track day next Saturday the 19th at the State Patrol Track. Even if you're not going to drive, I think you and your son would enjoy it.

ITM makes flat tops for the L28. Why do you think it will cost more to go with a 1 mm gasket? In my experience, felpro is often the least expensive, less than $30 at Autozone or Checker. I don't think you will notice any difference between 8.3 and 8.5, but unless you already have the thicker gasket, why not go with the thinner one?

You didn't say what head you're using nor which pistons you went with (flat top or dished). The stock gasket is 1.2 mm and the Felpro is 1.0 mm. I've used Felpro and had good luck with them but there are others who haven't. Unless you're running an N42/N47 head with flat top pistons, I'd go with the Felpro. But to be sure, use lengine.exe to calculate the CR with your configuration. If the CR is going to be around 10:1 with the stock HG, there's no point to pushing it higher - backing off timing to prevent detonation costs more HP than you get from the extra CR.