Xnke
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Posts posted by Xnke
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When using your water outlet there, how are you handling the thermostat?
This V2 is looking really excellent, the combustion chamber is tiny but who knows....maybe the spark plug towers can be left unthreaded and a diesel injector could be fitted!
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They'd have to be hardened, so either way you're paying the heat treater. Soft ones will just hammer out, gall your valve tips, etc.
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It's good to hear that there are no "worry points" popping up in the daily driving. How is the exhaust looking? Any sootmarks or cracking?
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I haven't had to clearance any bellhousing yet-but then again I'm using a 12lb CrMo steel billet flywheel, and an Exedy 350Z replacement clutch. I have over 1/4" in a 71B bellhousing.
Which clutch and flywheel are you using?
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So you are calling them a terrible carb, for being worn out? You realize that the round-top carbs that are so hightly vaunted suffer from exactly the same problems, and require the same work to get them to run right...
Anyway, Hope you get your carbs tuned up, KP910!
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The flat top carbs have a seperate choke circuit and power valve, plus the same style of needle-seat system the round top carbs have. IMO they're a superior carburator.
The main jet is fixed location-you can't adjust it. You'll need to actually adjust the needle taper instead. Standard SU needles for 0.090" jets will work. With the cam and compression, you'll want to lean the main jet a little from idle to 3000RPM, and richen it up from 3000RPM to 6500RPM. Go slow. It's easier to go richer than it is to throw the needle out and start over because you need to go leaner.
USE A WIDEBAND TO TUNE THE NEEDLE TAPER. It's really necessary if you want to really tune the carbs with any kind of speed and accuracy.
The power valve/accelerator pump needs to be clean and the diaphragm and rubber sealing washer checked and replaced...they're normally junk. It's a vacuum-operated accelerator pump so there is no mechanical linkage to adjust. It works well when it works, and when the rubber parts are in good shape, it works. If they're in bad shape, then the carb runs badly, overly rich and way out of tune.
The throttle shaft bushings need to be tight and smooth-no air leaks. If they leak air, the carburator will run lean and with poor vaccum signal the main jet and power valve will not operate properly-it will run badly.
They need to be synchronized, both at idle and part-throttle.
The damper oil *needs to be* SAE 20W, motorcycle shock oil is easily available in this weight and works well. Don't change this for whatever you have-it needs to be SAE 20W. The operation of the power valve and main jet depend on this damping rate. It's not like the round-top SU's where you can adjust for different viscosities easily. (nor is there a need to adjust the viscosity-the power valve makes that change useless and needless)
For reference, this is the procedure I use for setting up Flat-Tops. It's basically straight from the manual, and it works IF your carbs are in good condition.
1. Make sure that the valve clearances are correct, the ignition timing is set properly and that the spark plugs are gapped correctly.2. Top-off the oil in the dampers to their correct levels using SAE 20 engine oil. 3. Run the the car until the engine is at normal temperature. 4. Unscrew the balance adjusting screw and the fast idle screw until they both are well clear of their stops.5. Turn the slow-running adjustment screw until the engine is running at 650 rev/min (700 of automatic trans) 6. Turn the mixture adjusting screw in both directions but with in the limitations of the limiter cap, until the engine speed reaches its highest point. If the adjustment procedure exceeds 1 to 2 minutes, the engine should be revved to clear the inlet manifold.7. Reduce the idling speed by unscrewing the slow-running adjustment screw.8. Screw in the fast idle adjustment screw until the engine is running at 1400 RPM. Use a flowmeter against the air intake of the front carb and turn the meter setting screw until the upper end of the float is in alignment with the meter index.9. Now place the flowmeter next to the intake of the rear carb and by turning the balance adjustment screw, set the rear carb air intake volume to match the front carb.10. Unscrew the fast idle screw until the engine resumes is normal idling speed and check is return to satisfactory idling by revving the engine 2 to 3 times. The fast idle screw should be set finally so the gap is 0.78 in between its tip and actuating lever. Should any difficulty while making adjustments, check the linkage. I slight amount of free movement in the auxiliary and main throttle shafts which corresponds with the clearance between the throttle shaft end stops.11. With engine at operating temperature, and the mixture and slow-running speed correctly set, check adjustment of the throttle closure dashpot (Automatic trans)12. Set engine to 2300 and 2500 rpm. The button on the dashpot should just be in contact with the lever attached to the throttle linkage. Adjust the position of the dashpot if necessary to provide this setting.13. Now set the engine to 3000 rpm and release the accelerator quickly. The time it takes for the engine speed to reduce to 1000 rpm should not be more that 5 seconds. Any wide variation form this indicates a worn out dashpot and must be replaced or repaired.
Make sure your carbs are in good condition before you start. Make sure you don't have any vacuum leaks or cracked vacuum hoses, etc. Hard to make the car run right if half the stuff on it is no good-so make sure you go over it well!
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The T5 bell is a little tighter than the FS5W71 transmissions, you might need to clearance it a smidge for the pressure plate assembly. Most should clear fine, though.
The last few billet steel RB20/RB25 flywheels I did, I just welded the register bore and re-machined to a 80.00mm fit, the cranks I've had here measured 79.95-79.99 on the seating surface.
I wouldn't make such a big deal out of the flywheel register being off if it wasn't for the fact that when it comes off, it'll eat your feet. Also, the "mill 6mm off the back of the crank" story that goes around as a "japanese high-power crankshaft" modification is so that they can use unmodified twin clutch RB/KA flywheels, the register surface moves to the inside spigot at 35mm and the 81mm bore isn't used at all.
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Newzed....the full designators for the 71B/71C transmissions are FS5W71B and FS5W71C...so yeah, you got the info.
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Another thing to look at-is the clutch soft line blowing up like a balloon?
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You assume that the slave and master are the same diameter, NewZed.
Not all of them are. I know that in my Z, I have a 3/4" clutch master and a 5/8" slave...my slave moves further than the master. If I install a 3/4" slave then they move the same amount, and if I was to install the 5/8" clutch master and 3/4" slave, then the slave would move LESS than the master.
Check and see that your slave cylinder and master cylinder diameters are correct, while you're down there, TrikeZ
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Put the car on a dyno with 40's tuned to the best you can, and then with the 45's tuned to the best you can...won't loose any drivability and will only pick up power and torque...that's what I mean when I say 45's will always outperform 40's
Just because you personally don't miss the extra power, doesn't mean it's not there.
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The 40's are OK for an L24, for an L28 the 45's are always going to give better performance.
Run the 40's to break it in only if you already have them, then replace them with 45's to actually tune the engine. Or break it in with the SU's, and you can even run with the SU's if you tune then correctly.
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Use the big 62mm countershaft bearing, it's far stronger than the ZX bearing.
The guts of that trans are somewhat stronger than the ZX transmission WHEN you use the big bearing. If you use the small ZX countershaft bearing, you will get a box that is the same strength as the ZX box.
All the information concerning the conversion in that link is correct and verified. There are LOTS of gear ratios available in the FS5W71 series gearboxes...I have listings for 24 different ratio sets. There are multiple countershaft sets out there, then you modify the countershaft ratios by changing the input shaft ratios. Then 5th gear is independantly changable...it's a pretty flexible transmission!
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That transmission will work fine-just needs the bellhousing swapped over. The gear ratios are OK too. You'll need to drill the bellhousing for the 16mm shift rod, and cut it for the 62mm countershaft bearing, and clearance the boss on the back of the countershaft hole for the countershaft gear.
It is *very* likely you will not need to modify your driveshaft either, when I've used a 200SX transmission from behind a CA20E or CA18DET engine it's always been the correct length to drop right in place. Same with early RB20E/ET transmissions.
The shifter is NOT THE SAME as a later 240SX shifter, one bolt is in a different spot and one bolt is 17mm instead of 10mm. If you choose to go looking for an aftermarket shifter, keep that in mind!
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0.030" shims is fine. Just make sure you check your lash pattern and if it's good, run it. if it's running off the edge of the rocker pad, then you need thicker/thinner lash caps. Moving the cam so little means you probably won't have any issues.
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Dude, the 18G you had was perfect.
Just because you can make 280HP, doesn't mean you have to. A 13G is too small. A 14B is borderline too small. A 16T would be fine. An 18G is fine.
Bolt it on and go.
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That's strange, Tony...I have investment castings done in stainless and carbon steel in a US foundry for not terrible money. PM me and we'll see what can be done...
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Gee, I wonder how it's really done.
Oh wait, I do it here for many different cars...no big deal.
Yes, you can do exactly what you want, but you will need the following to do it properly.
1 LS engine block, stripped, with main caps.
1 LS bellhousing, auto/manual doesn't matter.
1 Z32 bellhousing
1 alignment jig, fitted to the input shaft bearing bore and the main bearing OD of the engine block.
1 tape measure
Acetone, stainless wire brushes, TIG welder, etc.
Do it properly and you won't have any problems. But, it'll cost you quite a bit unless you have the proper tools and machining/welding skills.
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Spiff, the answer is no. It won't work.
You need a programmable system, something you can adjust and control. If you're hung up on stock efi, try the later Nissan ECU's that have Nistune capability. If you can get one of those ECUs, then yes, it can be tuned to work well. Maybe some of the turbo volvo ECU's are tunable?
However, the stock 280ZX turbo injectors are not my first choice-pick something from a turbo volvo, I know you have plenty of those out there. A new fuel rail and modern injectors will go a long way towards easier tuning.
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Megasquirt is a solid system when it's installed properly. I'd say a solid 90% of people who have problems with their megasquirt systems can trace 90% of their problems to improper installation. (Saying that as someone who has installed quite a few of them, and fixed quite a few more for others.)
The tuners who scream and pull their hair out about megasquirt are doing so because they simply do not make money on them. It takes time and effort to fix the mistakes and poor planning that many systems show up to their shops with, and they are simply not going to do free work to fix it, just so they can charge you money to tune it. A big issue with MS is that it's perceived as "cheap", even though it's not really any cheaper than any other ECU in it's capability bracket. So, people who aren't willing to pay what it takes to do a quality install, or who take every shortcut they can, are who show up to the tuner with a badly installed, malfunctioning, poorly thought out megasquirt system. Then, when it has issues and can't be tuned properly until those issues are fixed, they do not want to pay for the tuning work done OR the time, effort, and parts needed to fix it so it can be tuned. There is also no tech support like there is for Haltec, Motec, Link, etc.
MS-2Extra, however....Extremely sensitive to noise. The PWM-based current limiting on the low-impedance injectors REALLY can mess with the processor, and having the ignition driver (BIP373) internal to the megasquirt produces even more electrical noise. Moving both of those things out of the main board (and out of the case) makes for an extremely stable, noise-free installation.
Stock EDIS-6 has an RPM limit of over 11,000RPM...so that's definitely not going to be slowing up your rev-ability! I don't know what the coil pack can handle though, but my supercharged L28 runs the EDIS with a chrysler minivan coil back and will turn 7800RPM without an issue.
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I made my sleeve. It's 0.020" thick...remember the 1mm difference is diameter, the thickness of the sleeve is radius.
The bolts were never designed to hold the shear forces like that. They are meant to clamp the flywheel to the rear of the crank, but they are not meant to be the sole locating force.
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eh, stock bottom end will handle a 7200RPM zing a few times with no ill effects...
Can't wait for the video!
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So, did you fit the shim to the flywheel or are you waiting for it to shear the bolts and come out to eat your feet?
The RB flywheel has an 81mm register bore, the L28 crankshaft is 80mm. Needs to have a thin ring pressed in to center the flywheel, otherwise the slightest imbalance will start it moving around and wearing on those flywheel bolts.
I believe I posted that information when I did this a few years back.
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That is something to try. Personally, without having a section of track/lonely road that I could run a step-test on I'd have to make that kind of timing change on a dyno to see the result, but a step-test could do it...
Twin cam head for the L6 from Derek at Datsunworks
in Nissan L6 Forum
Posted
Do you have a shot of the water outlet, to see how much meat is there for a flange/gasket face?