Jump to content

Bambikiller240

Member
  • Joined

  • Last visited

Everything posted by Bambikiller240

  1. Thank goodness for "Cut and Paste" functions
  2. If you experience uneven idle, hunting, or an idle that changes (rises or falls) as the engine's temperature climbs or drops, you probably have vacuum leaks. The most serious fault on most old SUs is wear in the throttle shaft area. To test for this, spray some carburetor cleaner on the outside of the throttle shaft; carburetor cleaner is non-combustible, and if the engine speed drops, it means some of this is getting into the air stream from outside the carburetor. You may also have leaks from the manifolds, from tubing such as the vacuum advance line to the distributor (if fitted), or from other places; the carb cleaner trick works well for locating those leaks as well. Other problems that SU carbs experience involve dirt in the dashpot and occasionally in the float chamber. The dashpot is a precision piece of machining that involves very close tolerances so that the piston doesn't stick or bind when it rises and falls. A little grit between the piston and the dashpot can make the car jerk and sputter. Take the dashpot off, wipe the insides down with carb cleaner and a lint-free, clean rag, and then reinstall it, getting the screws down tight. Also, don't swap the pistons between dashpots; they're matched to one another so that the clearance between the piston and the wall of the dashpot makes a tight seal but permits easy rising and falling. Dirt in the float bowl basically shuts off that carburetor (or can make it flood open, depending on whether the dirt is wedging the valve open or closed). You can try rapping on the float bowl with the handle of a screwdriver, but your best bet is to take the cover off, clean out the valve fittings, and reinstall everything, with a new fuel filter for good measure. Some older SU models also have adjustable floats, in which you need to set the float height (which basically equals the fuel level in the float chamber) by bending a brass rod. These carburetors were replaced in the mid-1960s with carburetors that had fixed, plastic floats that are basically trouble-free unless abused. The stop at the back of the floats can break if they are installed badly, and the brass pin that holds them in place can wear an oval hole in the float pivot. New floats are fairly inexpensive and aren't a bad idea if you're doing a rebuild. Grose-Jets are very popular with some people and a big pain for others. It appears -- and this is just conjecture -- that Grose-Jets work best in cars with adjustable floats, as they are longer than the stock SU float valves. The standard failure for Grose-Jets is to flood the carburetor. I have never had problems with the stock SU float valves or floats.
  3. 1. Tuning your SU carburetors by Scott Fisher, I've been meaning to write this up for some time, ever since I did the SU Performance Tuning 101 a few months ago. This one is more like Basic SU Adjustment for Happy Driving. The trick to tuning SU carbs is to understand that there are two things you need to get right: the airflow, and the fuel mixture. While they are interconnected, they are also independent, and need to be measured and adjusted independently. Special Tools You will probably need to arrange to buy or borrow a Unisyn flow meter. The Unisyn is the usual gauge for getting the airflow balanced between the two carbs. This costs about $20 and is simple to use. It consists of an adjustable opening (same size circumference, but with a disc on a threaded rod that you can screw tighter or looser) that you use to set the level of a little float that rises or falls in a glass tube at the side of the gauge. For the fuel mixture, I have become sold on a device called the Gunson ColorTune (maybe ColourTune, as it's a British co.). This is a spark plug with a crystal pressure- and heat-resistant window in it that lets you see into the combustion chamber while the motor is running. The color of the flame indicates the mixture richness. It costs about $40, and while it's not absolutely essential, it makes life so much easier that it's worth the cost. If you don't have a Gunson, I've included the standard directions here for determining correct mixture (step 4 of the Adjusting Mixture procedure). To tune SU carbs, first locate the following components: • Throttle linkage nuts. These are the things that connect the throttle linkage (the bar connected to your foot through whatever means your car uses, cables or rods) to the carburetors' throttle levers. • Throttle stop screws. These set the idle speed for each carb, and are located typically behind the dashpot, on the same side of the carb to which the throttle linkage connects. • Mixture adjusting nut. This is the lower of the two nuts at the very bottom of the carburetor. Later SU carburetors of the HIF type have integral float chambers, on which the mixture is adjusted by turning a screw. You'll need to experiment (and I explain how) to see which way makes this richer and which way makes it leaner. • Lifting pins. These are little wobbly metal pins under the dashpot. When you push up on the pin, it raises the piston in the dashpot. Find these; they're crucial if you don't have a Colortune. If you don't have or can't find them, you can raise the piston with a flat-bladed screwdriver pushed down the throat of the carb and twisted to lift it. • The bridge. This is the part inside the carburetor, where the gas jet opens into the air stream. You'll see a needle inside the jet, and the jet itself should be a few fractions of an inch down from the bridge itself. The jet is the brass tube that sits in the center of the bridge, with a tapered needle poking down into it. • The choke linkage nuts. Comparable to the throttle linkage nuts (and usually the same size), but on the linkage that goes between the choke cable and the mixture adjustment mechanism. They make sure that both carbs are enriched when you pull on the choke. Balancing The Air Flow 1. Start with the engine warmed up to operating temperature and perform your standard ignition tune-up (points gap, timing, spark plug gap, new condenser, etc.) first. If you've got a timing light and a dwell meter, you can verify all that stuff independent of the way the car is running. When it's warm, shut the motor off and remove the air filters. 2. Begin by balancing the airflow. To do this, first loosen the throttle linkage nuts. Leave them connected, just loosen them half a turn or so. 3. Back out the throttle stop screws till you can see that they are just touching the throttle stop. Then open each carburetor (that is, lower the throttle stop screw) 1-1/2 turns of the throttle stop screw and start the engine. It will probably idle at about 2000 RPM; don't worry. 4. Put the Unisyn over either carb and adjust the orifice in the Unisyn till the little float at the side rests at the middle of its graduated tube. (Pre-diagnostics: if the idle drops and the car wants to die when you slap on the Unisyn, the carb is too rich; if the idle soars upwards, it's too lean.) Hold the Unisyn over the carb for only long enough to see the level of the float, then remove it. 5. Place the Unisyn on each carburetor in turn to check its flow, adjusting the throttle stop screws until both carburetors register the same position on the graduated tube of the Unisyn. (The float will probably move either up or down in the tube, which is why you want to center it in Step 4.) When both carburetors flow the same amount of air, tighten the throttle linkage nuts, adjusting for the amount of free-play between the linkage and the throttle stops that your manual calls for (probably about 0.006"). Your goal should be to achieve the lowest possible idle with both carbs balanced and the engine running smoothly. (Note that the idle speed will very probably rise as you get the mixture correct.) If you've taken more than five minutes to do this, rev the engine to over 2500 RPM (assuming the idle isn't already that high) for thirty seconds or so to clear the spark plugs. Then adjust the mixture. Adjusting The Mixture: Note: in the following procedure, one "flat" is the basic increment of adjustment, and refers to 1/6 of a turn of the mixture-adjusting nut. This corresponds to the flat faces on the nut. I'm going to give instructions for SUs with the separate float chambers. If you have the HIF integral-float carbs, you'll have to look in a manual to see whether you turn the mixture screw to the right or the left to make it richer or leaner; I've done that once but I can't remember. Alternatively, you can -- with the motor shut off -- peer down the throat of the carb and turn the mixture screw while watching the top of the jet. Remember that moving the top of the jet up will lean out that carb, while moving the top of the jet down will richen it. 1. Shut the car off and loosen the choke linkage nuts. 2. Adjust the mixture nuts (screws) fully lean. For separate float-chamber cars, this means raising the mixture nut all the way up against the bottom of the carb (or rather, against the spring). For HIF carbs, you can try turning the screw while looking down the throat to see which way the jet is moving. In either case, the idea is to zero out the jet: raise it all the way up in the bridge. 3. Now drop the jet an equal amount -- two full turns for HS-type carbs, two full turns (I believe) for HIFs. Then start the car. Note: In the following step, you might want to consider adjusting the carburetors one-half a flat too lean, as the mixture will be enriched when you put the air filters (which restrict air flow) on at the end of the tuning process. 4. Raise the lifting pin (or use a screwdriver if you don't have the pins) so that the piston rises no more than 1/16". Listen to the engine's exhaust note and compare it to the following conditions: • If the exhaust note rises and stays high till you drop the piston, this carburetor is adjusted too rich. Turn the mixture nut one flat (one-sixth of a turn) up, moving the jet toward the bridge, then repeat Step 4. • If the exhaust note falls and the car sounds as though it is going to stall, this carburetor is adjusted too lean. Turn the mixture nut one flat (one-sixth of a turn) down, moving the jet away from the bridge, then repeat Step 4. • If the exhaust note rises briefly and then settles back down to something like the original RPM level, this carburetor is set correctly. When you have achieved this setting for both carburetors, continue with Step 5. 5. Tighten the choke linkage nuts so that the choke cable will pull an equal amount on both mixture nuts when you pull the knob. 6. At this time, I find I usually have to adjust the idle again because getting the fuel mixture right usually changes the idle speed. Since you know you have the throttles synchronized, I normally just adjust the idle without loosening the throttle linkage. The easiest way is to screw one of the screws out till it doesn’t' even touch the throttle stop, and then use the other to get the idle speed right. When that's done, you can screw the other stop screw down till it just touches the stop on that carb and you're set. 7. Replace the air filters and go for a test drive! Notes SU carburetors are most fuel-efficient when slightly lean, and provide the most power when they are slightly rich. You can use this knowledge to provide a certain amount of tuning for the kind of driving you do. If you learn to read spark plugs, you can get a basic idea of what your engine's condition is and make fine adjustments to the mixture nuts accordingly. If you have a ColorTune, you simply install it in place of one of the plugs, and then adjust the carburetor that feeds that cylinder (the front carburetor for 1 & 2, the rear for 3 & 4). The ColorTune will let you see the color of the flame. White flashes mean too lean; yellow flame means too rich. Blue (like a Bunsen burner) is correct, and blue with a faint orangish tinge is the best for power. You can also modify your car's throttle response characteristics slightly by adjusting the viscosity of the oil in the dashpot damper. SUs are set up so that a thicker oil will resist the piston's attempt to rise in the dashpot for just long enough that the engine's increased load (when the throttle is opened) will pull more fuel across the bridge; this enriches the mixture and temporarily bumps power up to help the engine achieve higher speed more readily. If you modify your engine, you will probably need to modify your needles, as it is the needle profile that determines the mixture curve for different air-fuel loads.
  4. Bambikiller240 replied to Mike's post in a topic in Body & Paint
    Both MSA and Vic Brit sell the Precision Replacement Parts weatherseal kit. I haven't heard of another company that manufactures a kit for our 1st Gen Z's Regarding Nissan selling the Precision kit as their own, I'm not sure about that unless they started doing so very recently. But last October, I bought an OEM set of door seals from Courtesy in TX, and they are the original style "soft" seals ( in Nissan bags w/ P/N) that require the separate plastic/metal channel. They were significantly more expensive than Precision seals priced through the other sources mentioned above.
  5. I’m about to start assembling the Cylinder Head and Timing parts onto my recently rebuilt L24 short block and I need some guidance from all of you L24 Experts out there. This is a completely stock engine, cylinders were over-bored .50mm, and since the crankshaft was in excellent shape, it was just polished. I have a stock early E88 Rebello rebuilt Cylinder head, all new Timing Components, and Oil/Water pumps to install. After the engine is up and running, I plan to install ZTherapy SU’s to top it all off. I’ve done this a couple of times, but it has been almost 20 years since the last time, so my memory needs major refreshing and I’d like your opinions, guidance, and answers with the following questions. Thanks in advance for any advice you care to share. 1. The Head Gasket that I got from MSA doesn’t have any “sticky” sealing material on it like the head gaskets that I’ve used previously. Should I put something on the gasket, or the block? If so, what product would you recommend? I’m not inclined to use “spray paint” like some have suggested. Is there a product that I can or should buy for this use? 2. Which bolts/nuts should I use RED Loctite, which should get BLUE Loctite, and should any get GREEN Loctite. Which fasteners should I use Anti-Seize on, and should I use”regular” Anti-Seize, or is there a “High Temp” or some other variety for certain applications? Are there places you would recommend that I NOT use any form of gasket sealer (like Permatex High-Temp RTV Sealant) such as the Oil Pump to Timing Cover gasket 3. Should I coat the Cam, Rockers, Timing Gears and Chain with Moly Grease, or something else to protect them during initial start up of the engine? 4. Lastly, Please give me your best advice including Tips to make things easier/better, things to watch out for, mistakes to avoid, etc. Any advice that you wish someone had shared with you before you started your last engine assembly would be greatly appreciated. Thanks, Carl
  6. I just grab the lip of that locking piece with my trusty Channel-Lok pliers and wiggle it out of the groove that it locks into. Never had any troubles. Use a small ball-peen hammer to tap it back into the groove when it's time to install.
  7. The spindle that we are refering to in this thread is the PIN that connects the Lower wishbone (A-Arm) to the strut housing. The part that you are refering to is the "STUB AXLE". I do not know how difficult it is to install the stub axle. (I haven't needed to do that job yet)
  8. Bambikiller240 replied to nutxo's post in a topic in Help Me !!
    That is the site that ZMeFly (ZMeCruise) posted a link to in the 2nd post of this thread.
  9. I haven't used the tool, but I can atest to spending an afternoon trying to remove one pin. Then an overnight SOAK in WD40, then most of another day trying to remove thatone pin. Finally spent $50 to have both pins pressed out. Buy the tool, you will be time AND money ahead. Just my $.02 Carl
  10. Bambikiller240 replied to korg_geek's post in a topic in Open Chit Chat
    Thanks for the warning. If it sounds too good to be true, IT IS! Cash or Certified Funds only. If you don't know the buyer, contact the bank that the check is drawn upon before accepting it. Better safe than sorry! A real, honest buyer will understand your concern.
  11. Bambikiller240 replied to Tourniqet's post in a topic in Interior
    It is available from Victoria British, and probably from Nissan, but it will be expensive for what it is.
  12. Unless I'm reading your post wrong, it SOUNDS like you fixed the plastic box, NOT the electrical problem that CAUSED the box to meltdown in the first place. You need to fix the functionality first, then worry about the cosmetics. Usually when the fuse box melts it is because of: failure of a component, which may cause resistance & generate heat in the circuit corrosion of wires or connections/connectors, which will cause resistance & generate heat overloading of circuits with more demand for power than the circuit was designed to deliver safely, which will generate heat [/list=1] Sadly, I am not an expert on troubleshooting, so I cannot advise much except that you need to know what demands you are placing on the circuit that melted (did you add something that requires more power than the circuit can safely deliver?), need to examine all of the connections and clean them (maybe even solder them) throughly, and make sure that all components in the circuit are functioning properly and not drawing excess current though the circuit. HTH somewhat Carl
  13. Bambikiller240 replied to Dreco's post in a topic in Open Chit Chat
    I understand what you are saying, Rick Darius seems (I don't know him personally) to be a major thrill seeker as can be seen if one follows the links to his website and browses around the video files. Given the cost to build his supercharged LT1 powered Z car, I suspect tire expenses are of realtively little concern to him.
  14. Bambikiller240 replied to Dreco's post in a topic in Open Chit Chat
    Well, I'm basically a purist, but Darius' Z is really a well engineered car. I certainly do not think that "butchered" is the appropriate term for this vehicle. If any of you have seen the video of it roasting the tires in 3rd and 4th gear while going up hill, you have some idea of the performance this car is capable of putting down. It is really an amazing performer.
  15. Bambikiller240 replied to Dreco's post in a topic in Open Chit Chat
    Got any extra tickets?
  16. Bambikiller240 replied to z_boi's post in a topic in Help Me !!
    I'll keep an eye open for it in the Pleasanton area.
  17. Bambikiller240 replied to El Gabito's post in a topic in Open Chit Chat
    Try ZHOME
  18. These are the MAJOR seals for the doors. 76801-E4100 Weather seal, Passenger Door - 1 Req'd 76802-E4100 Weather seal, Driver Door - 1 Req'd There are other small seals on the bottom of the doors, on the front of the doors, and some small ones on the rear-most part of the doors where the door sheetmetal meets the window frame.
  19. Bambikiller240 replied to nutxo's post in a topic in Help Me !!
    OK, I need to make some assumptions before we go into this: I assume that your engine is complete and installed in the car. Right? Also, I assume that you know the difference between an intake manifold and an exhaust manifold. Right? If not, stop right now and take your car to a mechanic for the valve adjustment. You are not ready to tackle this job. All you need to do is look at the manifolds. The INTAKE valve for a given cylinder is DIRECTLY across from the INTAKE MANIFOLD RUNNER for that specific cylinder. Same for the EXHAUST valve being DIRECTLY across from the EXHAUST MANIFOLD RUNNER for that specific cylinder. You must look to see which manifold is DIRECTLY across from EACH valve you want to adjust! Due to the design of the cylinder head and manifolds, it is not as simple as Intake, Exhaust, Intake, Exhaust, Intake, Exhaust, etc. From the front of the engine (Cylinder's #1, #2, #3, #4, etc.) working towards the firewall it starts with #1 EXHAUST, then #1 INTAKE, then #2 INTAKE, then #2 EXHAUST, then #3 INTAKE, then #3 EXHAUST, then #4 EXHAUST.......etc. Look to see which manifold is DIRECTLY across from EACH valve and you will see what I mean. It would be easy to spell it all out for you, but you would be better served to look at your engine and follow what I've given here to get you started. Confirm that you see what I'm talking about and apply the information to the remainder of the engine. This should get you started on learning about your engine. If you do not have a shop manual (at least a Haynes manual, or preferably a Nissan Factory Shop Manual) please consider getting one. It will be the best money you can possibly spend to maintain your car.
  20. It is the seals that go on the body that you want, there are only small seals in various positions that go on the doors. Courtesy Nissan in Richardson, TX is your best bet for a good price. I can dig up the part numbers this evening if no one else posts them.
  21. Bambikiller240 replied to av240z's post in a topic in Old For Sale Ads
    Try Ground-Control Website click on Application Guide link. I suspect it is a generic picture, but they don't seem to have specific model pictures.
  22. Bambikiller240 replied to 26th-Z's post in a topic in Old Want Ads
    Eric: See the newly created forum for Dashboard Restorations. They are now a supporter of the club and I believe that Jim of Dashboard Resto was trying to arrange shipping for a group order through a thread in that forum.
  23. Thanks for the pic. So, that one is a MILD one? Geez, I can't imagine what a hardcore bogan ute would look like!
  24. OK, I'll ask. What then is a bogan?
  25. Bambikiller240 replied to go z racer, go's post in a topic in Open Chit Chat
    Hi Jerry! How have you been lately? Yeah, I did see the British GP this AM. An interesting race with several good dices and some great passing. I do wonder how many pounds (or Euro's) Bernie paid that WACKO to embarass the BRDC by running out onto the Silverstone course durring the race? It certainly messed up the pit strategies of all the teams. So, when are we going to Vegas for a "hunt"? EDIT: After THAT comment, do you think we would let 2Many be our gunbearer? Not a Chance!

Important Information

By using this site, you agree to our Privacy Policy and Guidelines. 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.