240ZMan

I've been hearing clunks and squeaks from the rear end when I start up and lift off the gas that I would usually associate with a failed differential mount. But mine is quite solid. After poking around underneath for a while, I noticed that the nose of my differential is aimed a bit to the right (passenger) side of the car. In fact, the nose is rubbing against the mounts for the strap that helps contain the up/down movement of the diffy's nose. I circled the area in the 2 photos. My diffy is an R180 4.11 from the front of an 85 Nissan 4x4 pickup. I've checked that all the mounting bolts for the rear suspension look ok, and all are tight. I've had the diffy installed for a year, and the noise only occured after I replaced my springs and struts just recently. With the front cross member off (as in the pictures) I can pretty easily push the nose to the other side, but the moustache bar pushes it back to the right as soon as I let go. I tried wedging a big screw driver in to move it over, and then reassembled the front cross member. The clunk/squeak was gone for the first few hundred yards, but then it came back. I can see that nose has moved back to the right. I was thinking that perhaps there was some piece I put back inverted/reversed, but can't find anything that could fit any other way. I'm sure there has to be a simple solution to this, but I'm just not seeing it. Any suggestions?

On my stock L24 engine the scale was on the driver side of the engine, and on the L28 from an '80 it was on the passenger side. I don't know what year it switched sides. In both cases it's attached with bolts that also hold the timing cover. I suppose it's possible someone before you "forgot" to replace it when they had the timing cover off. But it would sure make setting the ignition timing difficult. Unless they just did it "close enough". Let us know what you find.

I agree, I have the same concern. If I go that route, I'll either mount the retractor's tab directly with the existing bolt, or fab a small bracket with a very minor bend (~15 degrees)in it so that the retractor will clear the curved roof section near there. That way if there is a big "pull" on the retractor, I won't have to worry about the bracket twisting and bending.

There's a guy here local with a '71 or '72 who has the retractors mounted up on "B" as shown in my picture. I had wanted to emulate his install, but he didn't know where the seatbelts had come from. Now I'm guessing it's WELR-N from Wesco. Side note: his car looks a lot like Arne's, same color. Excellent condition!

Ah, that clears things up some. I just spoke to them and the woman also suggested the WELR-N belt which would have the retractor mounted directly at "B" in my previous picture. Did you consider that one? I figure it's an easier installation, no brackets are involved, but you do have the retractor out in the open where it's visible. Not the most attractive, but I'm thinking it might be a bit more robust in an accident since there's no bracket that could twist/break. I hope I'm not over analyzing this, but given it's about our safety, I figure it's better to err this way...

This is great Montezuma, thanks for letting me ask 20 questions! I was wondering how you mounted the retractor behind the seat? Looks like there are 2 bolts holding the stock retractor in. I'm guessing that the one farthest from the door was used for the retractor, and the one closest to the door for the other end of the belt? Is that correct? Or did you use the bracket to mount both the retractor and the belt end to the same outer bolt? And which mounting point did you use up top? Here's a picture of my car. Did you use A or B? I'm guessing B because that's where the original factory was attached. Any chance of a picture?

Montezuma, which model did you choose? Did the retractor for the lap portion fit into the "pocket" that holds the factory's retractor? Or is it mounted outside? Also, did you go with a retractable shoulder belt? I've been looking for a combination lap/shoulder that's retractable that will fit my '73 without successs so far. Perhaps you've found the solution

Keep in mind that if you change your cam, you're going to change the sound of your exhasut. When I first put my 2 1/2" system from MSA on my L28, I had the stock cam and I too felt it was too loud in the middle rpm range. So I put an 18" glass pack on and the result was very livable, and still let me hear the engine. When I went to a more agressive cam, I was dissappointed that the exhaust note seemed to be much flatter. Then I added triple webers and I could only hear them. So I took the glass pack out, and it sounds great. It's probably too loud above 4k, but at the track it sounds sweet. Just something to keep in mind if you have a new cam in mind

I think that your issue #1 is not due to the shifter, but to something not right inside the transmission. Likewise, #2 also sounds like one of the forks or rods has "issues". When I did my swap to an '82 5 speed, I kept my 4 speed shifter since it fit without any modifications. But putting the 5 speed shifter in would NOT have given me the extra movement to the left of 1-2. I hate to say it, but I think the tranny needs help.

I'm confused by your description of the corrosion as "black". Usually "corrosion" of the cable where it attaches to the battery is white, which is the color of lead sulfate. It occurs because the sulfuric acid in the battery leaks/splashes/vents out to the top and reacts with the lead fitting on the end of the cable. I have no idea what would cause black corrosion on lead.

TomoHawk, you used the diameter instead of the radius. Here are the correct values: 2" muffler outlet = 3.14 sq. in. 2 1/4" muffler outlet = 3.97 sq. in. 2 1/2" mufler outlet = 4.91sq. in. dual 1" tips = 1.57sq. in. dual 1 1/4" tips = 2.45 sq. in. dual 1 1/2" tips = 3.53 sq. in. Also, along the lines of what someone else said, 2 smaller pipes with a total cross section the same as one larger pipe will still provide more resistance to the flow of the gases since there is more surface area of the pipe for the gas to pass by. Keep in mind that the speed of the gas right at the surface of the pipe will be zero. So all else being equal, a single pipe will flow more than 2 smaller pipes of equivalent cross section.

I don't recognize the part number you're giving, so I'll assume that the dizzy came out of a Z. If it did, then by 3k rpm you should be seeing ~20 degrees of additional advance, more or less depending on which dizzy it is. So I'd say you are correct, your mechanical advance isn't working. With the engine off, take the dizzy cap off and see if you can move (rotate) the plate. You should be able to move it a bit. If not, then that's a clue

Given that the sound goes away when you disengage the clutch, it sure does sound like the main shaft bearing. Perhaps if you wiggle the shaft with your hand you can feel excessive play? Maybe turning it by hand will give you a clue? Or maybe since you have it out already, you should change it now. I say this without knowing how easy/hard it is to do that. The transmission is one of the few things I didn't rebuild myself.

Do you think that ignorance is part of it? For example, the other day I saw a honda civic, completely stock (at least what I could see outside the car) with a huge rear wing bolted directly to the top of the trunk. If there was any bracing I couldn't see it. Front wheel drive car. Car wasn't lowered. Tires were skinny all-season rubber. I can't see how the wing could have any positive affect on the car. What was going through his mind when he spent money and time to do that? Ignorance? Just experimenting? Or something else?

Good point, I doubt any of us would see it that way. What I meant (and should have been more clear on) was adding things that appear to improve performance, when indeed they don't. Do you all think that's a better description of rice? BTW, I don't have any strong feelings on this. If I see someone who does things to their car that I would never do to mine, I just hope it's making them happy. I know others would never make some of the mods I've done - (too noisy, rides too rough, etc).

I think there's a fine line between "rice" and "mcgiver". If you're putting the edging on the front of a real airdam as a low-cost way to reduce airflow under the car without having it break on every driveway, I think that would qualify as a clever and economical solution. If it was just to look "cool" (or whatever the current term dejour is), then I think it's rice. BTW, I added the old-style BRE spook to my '73 strictly to improve higher speed stability and I was amazed at how much of an improvement there was. The older Z's really have poor aerodynamics. Seems to me that there is a consitent feeling from this group that rice is when things are added with little/no real-world benefit.

Arne, I would agree with everything you wrote for a street driven car. During the winter months that's been exactly my experience. But for the days when I'm on the track, no amount of pulling up on the parking brake will tighten the brakes back up, and my pedal gets longer every session. Also, with my swap to the Toyota calipers and vented rotors up front, I've got too much front brake bias, so need to do something to balance things out. The rear discs with adjustable proportioning valve looks like the trick. I'm in the process right now of gathering parts for the swap using the Modern Motorsports brackets and 240SX calpipers/300ZX rotors. I have one more track day this season in October and will hopefully have them swapped by then to see how they do.

That's a great find! A ZX 5 speed with a 3.9 diffy is a sweet combination for a daily driver. In my case I'm running a 4.11, but I'm at altitude so need all the torque help I can get. And mine is a weekend toy car. http://www.geocities.com/z_design_studio/transmission.html Use this site to figure your cruising rpm and max speed in each gear, and compare that to what you have now. It was the most helpful site I found when planning my swap. I would suggest you decide now what the max RPM of your new engine is going to be. The more agressive you go on the cam, the more agressive (higher number) you'll want to be with your diffy.

Hard to see from the pictures, but the interior looks more like 132,000 miles.

It's been a few years since I had it on the car, but as I remember, the carb vents had their own nipples on the back of the air cleaner. When I switched to an earlier air cleaner. it only had 1, so I had to use a T on the carb vents. Also, my '73 L24 block had a 1/4" nipple brazed onto the side of the 1" vent (nipple) for the PCV hose. The L28 was missing the 1/4" nipple so I routed the fuel tank vent to the air cleaner instead.The only real downside I remember with using the '73 air cleaner iis that the bottom of it (when mounted on the carbs) extends down farther than the earlier air cleaner assemblies, so it was virtually impossible for me to fit my hands down around it to turn the mixture adjusting knobs. I had to pull the cover off to have enough clearance. But my hands are on the large size, and perhaps someone with smaller hands wouldn't have had this issue. Plus if you set them and then leave them alone, then this wouldn't be an issue. I like to tinker too much

When I bought my '73, it still had the original air cleaner mounted to round top carbs with adapters. I'm pretty sure I still have both the air cleaner and adapters somewhere. PM me if that's what you're looking for.

I just built one from scratch for my '73. I took my time one Sunday afternoon. About the only tools you need are a jig saw and a drill. Most of the time was spent gradually trimming the top piece to fit the curve of the car. And don't worry too much about making it pretty, the carpet will cover it and make it all look good. I already had the 1/2" particle board, so my total cost was about $18 (12 for the carpet at Checker, and 6 for the spray glue at Home Depot.) Go for it.

A few years ago I replaced the stock E88 on my L24 with an E31. Everything else was stock. I could not feel any difference in performance.I think which head you use really only makes a difference when you begin to modify your engine. For stock, use what you have as long as it's in good condition. BTW, I now have an N42 head on N42 block with flat top pistons and love it. I recently sold the E31 to a friend who is still running his L24. For me, the N42 offers more performance potential due to its bigger valves. I'm right at the limit of what I can get away with for compression ratio. The even smaller chamber of the E31 would be over the top for my setup. My point is that the "best head" question has different answers depending on the rest of your engine and any rules you may have to follow.

I too went with the MSA header and exhaust and had to have a local shop do the final fitting. I thought I'd add a lesson learned to this thread. When I first installed it I had the stock cam and thought it was just a bit too loud for where I live. So i had an 18" glass pack installed just ahead of the rear axles. The sound was nice, not too loud with the windows open, and reasonable with the windows closed. Later I switched to a mild cam and the sound changed a lot. The throatiness was reduced a lot, too quiet to my ears. Then I added triple webers and found that all I could hear was the intake of the carbs, so I removed the glass pack. My point is that the cam has an impact on the sound of your exhaust, and if you have plans to change the cam, you may want to hold off on changes to the exhaust.

I don't know why he would say that. I just went out to the garage and fit my synchrometer into the rubber DGV adapter with no issues. I also have a syncrotester that's more round than the oblong base shown in the picture and it works too.