Tony D

"Alot of the engine response strangness comes from emission control devices like the BCDD valve in the older EFI cars." INcorrect! The sluggishness of the OEM system is DIRECTLY linked to it using a flapper-style AFM. There is an inherent delay of response due to simple inertia. Almost EVERY SINGLE ONE of the emissions control devices comes into play when you CLOSE the throttle, not when you open it! As a matter of fact, during WOT NONE of them are functioning! Matter of fact, over 3500 not much is going on with them either! The sluggishness goes away with aftermarket systems because they measure MAT, as well as having accel-shot functions. They all drive similarly to early GM TBI systems, which were MAP based as well, and didn't have response issues inherent in the Bosch system. The key to responsiveness is to keep the flap close to open. It's why the cars are geared to run on the freeway around 3K rpms. This REALLY helps throttle response. And in fact, the response above 3000 for an aftermarket and stock system is hard to differentiate. Most people drive their cars so poorly that they attribute ills to the system that are really inherent in their misoperation of the vehicle. And of course the Emissions Bogeyman comes up and is blamed for it as well. I don't know where that comes from, they all go inop at WOT, and most function to decrease emissions on overrun (drop-throttle)!

Generally the KA Tranny is acknowledged to survive to 400HP, while the original L-Series won't last long if you are constantly using 300+. For over 400, the Z32 Tranny seems to be the adapted choice. You have to be careful with 'exploded gears' as a diagnosis. Is this due to countershaft flexing, bearing failure, or shock-loading. You can break ANYTHING with shock-loading. I've broken low-mileage L-Series Trannies with a stock L26 because the bearing retainer let fly and the gears moved allowing high loads on the face to shatter them. Many times gears are broken because bearings allow improper alignment and the face contact of the gears change---add to that a shock load and it APPEARS the gears are at issue, but in reality it's bearing failure or other flexing of the case/components. I don't know what happened with your fifth gear, but the round nut backs off on those allowing failure. I spend a lot of time at work analyzing broken gears, twisted shafts, broken stuff of all types. To a casual observer, one cause may make sense, while in reality the failure is something completely and seemingly unrelated. When you see a broken component ask yourself "WHY" Five times on each answer you give yourself. If you can't answer it all five times...you're likely overlooking something!

" Although I would have to ask why did the engineers enlarge the shaft to begin with, I would assume is they have had a number of them bend during hard shifting?" I missed that, but deflection may be a reason to upsize the rod. Turning down the ends of an immovable pilot point will not have any effect on this function. I would not say 'bend' as that implied they took a set. I would probably say the more correct word would be 'deflect' which made shifting harder. And with the IMPROVED shift linkage in the tailshaft, more force can be applied. Again, turning down the pilot end really isn't a factor. Look at the Clutch Input end of the tranny to see the exact same turning-down of a critical input device. And everybody does it! This all involves the front case, I don't know where you get the idea you cut the whole thing down, just where it pilots into the end. Then you don't have to drill anything and the factory alignment of the rods is preserved... Remember, I'm not the guy talking about prospectively using a hand-drill on the operation. You want to bind the shift rod, misalign those holes a mm or two when the drill skips around a bit. See how nicely they shift then. By turning down the shaft, that potential fail in aftermarket machining is eliminated. And it IS a REAL concern. Any monkey can run a lathe. Center-Finding the hole and then competently redrilling it or machining it oversize DOES take SOME skill in machine work.

Are you serious? Are you seriously saying the shift rod in these transmissions is a point of failure. Well, I've been into and out of them since about 1984 and I have YET to see a rod cause a failure. The roll pins through the rod yeah. And with a machined case, there is logic (as I stated) about leaving as much meat in that area as possible. I just mentioned it as 'that is what I saw them doing in Japan' and they've been doing this swap for quite few more years than we have on this side of the pond. I don't see why they would machine the case and NOT bore up the shift rod. It does seem easier to me to do it that way. But 'serviceability'---that's a moot point in this discussion. If you are seriously considering failure points, the CASING and BEARING come FAR before 'sliding back and forth shifting rod'! Casings I've seen split, gears break, but MOST OFTEN: BEARINGS FAIL. The largest reason these transmissions STOP you on the roadside is a BEARING. A synchro that goes bad will not make a bit of difference on the road. Bungee the thing in gear and drive on (been there, done that, TWICE.) But the bearing comes apart, and that shaft deflects? You start rapidly grinding gears to nothing. If you are saying you do this swap at the roadside, I call bullshite. Unless you got the premachined casing sitting in the back of the car when it happens, this is NOT a 'roadside swap.' Seriously, roadside maintenance? When was the last time you rebuilt a Datsun Transmission on the roadside? That's way out there as far as I'm concerned. Not a factor. EITHER modification path is a ONE SHOT deal. Once the machine work is done, you're finished forever. If you don't change the bearing, you have a failure prone part left inside. A part which you already have to swap from one tranny to another (or buy new.) For me there is no big difference in the shift rods. If you are rebuilding the thing, it's up to the person doing it. I guess there is an argument to be made that cutting down the rods makes for a stronger front casing. But if you are going through the trouble to do the swap, the larger bearing is compatible and designed for the torque handling capability of the transmission. I'm all for quick and dirty swaps...but there is a point where it doesn't have a payback. I feel this is one of those instances. I have half a dozen of those five speeds with THAT bearing failed sitting in my container. It's the prime motivation to have gotten a couple of the later trannies in the first place. Stronger. Less apt to fail. Same serviceability, but with a better shifter. I just never thought someone would claim the reason not to use the bearing was because they might have to do this on the roadside one day. I got news, THAT ain't gonna happen!

Yeah, that's where that bunker style house I've been obsessed with since High School comes into play, along with my dedicated cadre of local mercs who depend on my benevolence for the village's livelyhood. It's rumored "Apocalypse Now" as opposed to being a historical drama, was actually a prophecy on my final demise... I mean, I'm just sayin'... No resemblance whatsoever right? I'm safe, I'm not going Insane. Really!

It's 'free' if you are using energy that is usually wasted (heat and velocity) to induce the amplification flow. An engine's exhaust on the way out the tailpipe is about as far down the 'work' ladder as you can get. Once it's out the pipe, you can never recover ANYTHING from it ever again. Why not use that last bit of heat and velocity energy to scavenge the surrounding airflow into a dilution scheme to mitigate fumes at least??? Caterpillar last year revealed an auxillary turbo-like device that takes a turbine wheel downstream of the turbocharger outlet, which turns through a geared reduction box and fluid coupling (like a torque converter) to impart exhaust gas energy back to the flywheel. It was between a 1 to 3% recovery. Doesn't seem like much, but it was money down the drain as wasted exhaust flow.

I feel the safest when I can sling arms and return fire with anything I can pick up on my own, without restriction. That kind of rules out USA---where should I go? Texas?

"The more formal education you have, the more difficult it would be in this economy to find employment matching your qualifications." I think that is part of the problem, because people bought into the lie that education automatically entitles them to some set salary, they actually BELIEVE they will get it! I got news, education is great, but it doesn't entitle you to anything other than the consideration that you have the education. Having the education doesn't necessarily mean you can do anything useful for a prospective employer. Skillsets, demonstrated and proven do that. In many cases, regardless of advanced degrees. If you get hung up on what you are 'entitled' or 'should' make because you have a Masters Degree (or whatever) it can be a bumpy road. Ask all those unemployed UAW workers who had high school diplomas (!) and now can't find a job that pays them $120K+ per year. They'd been taken in by the same sort of lie. Beware! (Again, speaking of the third world: there are plenty of software companies in India where Masters and Doctorate degree holders make 45 and 60K a year. It sounds 'well below market rate' until you realize on that salary, in that country, you have servants, drivers, basically living like very high income people. But because of the salary many people did not choose to relocate when the jobs moved there.) Salaries are regional, and many times skills based more so than entry-level positions where they only have a diploma to look into... Once your CV starts getting filled with competencies and proven abilities, the money takes care of itself. It's important to let employers know what your salary range is---many times prospective employees are not considered based on the assumption that with X Degree they will want $X... If it's not the case, if you REALLY want a particular location or job and money is not a factor, you need to let them know that. It happened to my father, who was semi-retired and found they had hired another person for a job opening without even calling him. The reason they didn't was 'we couldn't pay you what you're worth'.... My dad told them "let me be the judge of that"---at that point he was willing to work for MUCH less than 'the going rate for his qualifications' simply to keep busy at a job and add to his pension a little bit. The job was short term anyway, it would have been a perfect match. As it was the guy they hired didn't work out, and he ended up there for the last five years before retiring, and then did consulting work for almost another five years!

The head gasket I listed was a late-model L20ET unit. The bores are oval. If you have the stock L24 bores, the fire ring will be cutting across the edges of the cylinders and hanging in the combustion chamber. It is only for the L20A bore, with the larger diameter of the 'oval' apparently for people who want to install L28 Valves into the small bore L20A...and then consequently relieve the hell out of the block for clearance! It's an L20A - only part. Sorry!

Uh... think about it for a second more 72 SBC 240Z.... think about it...

John C's comment bears an additional comment. Those are what is called in the compressed air and gas industry 'volume increasers' you see them used in safety blowguns, and that is what function it is performing on that diesel truck exhaust---that little funky divot in the tailpipe extension brought out simply draws in ambient air through the functionality explained earlier, and drastically dilutes the exhaust stream. One thing to think about is that in CAGI (compressed air and gas industry) these are generally classified by ratios, i.e. 7:1 meaning for every one CFM you put in at X psi, you will get 7 CFM out, at a reduced pressure. The nozzle ratios may even be in the CAGI Handbook. Anyway, something that bears investigation is the issue of 'fumes in the interior'---with a proper NOZZLE TAILPIPE on an early S30, you could DRASTICALLY dilute that toxic mess coming out your tailpipe, making your leaking rear deck area less able to suck in noticeable concentrations of malodorous gasses. I think this is something overlooked TOTALLY in the discussion of solutions to the problem. Of course proper sealing is paramount. But since almost EVERY solution involves using a tip extension, why not use a FUNCTIONAL DESIGN to extend the tip, and at the same time dilute that exhaust flow to make any leaks less noxious? Well, off to Funan Digital Mall to go buy my Tom Tom S.E. Asia. Yeah, I'm actually going to buy a GPS...mostly because I'm sick of being tied to taxis and other people driving me around. I want to go out and explore on my own. I digress...

Did you do the wiring before or after the body was put back on the frame? I've seen it where wiring was inadvertently pinched or cut in the process of putting the body-on-frame and that can cause all sorts of weird ghosts. (Usually in a place where you can't see it!!!) Never seen it on a 240Z though.

I got the same daily driven mileage with the Shark car (17mpg) whether it had SU's on it, or Triple Mikuini Blow Through Carbs huffed into for 350RWHP. Same route daily, 26K miles a year for several years from Corona to Brea through Carbon Canyon. It amazed me that the horsepower increase was achieved at anywhere near comparable fuel economy. You had to work the engine pretty hard with the SU's to get decent performance, but with the turbo...I rarely found myself WOT all that often given the speeds reached! Yeah, I could get 5MPG on the track with the Turbo. But that also isn't much worse than SU's run at the track, either! If you use horsepower, you're going to pay a penalty. Frankly, the car was a misery to drive with the puny N/A output. It just didn't have (comparatively) enough power to get out of it's own way on the freeway. And that's coming from the owner of a 1200CC VW Bus!

Thanks for the information MADKAW. That will make Andy very happy as well! I'm laying in a big order when I get back to the states!!!

I would agree, one of the primary reasons to swap to the later transmission is strength--the gears are wider. To leave the early bearing in there defeats the purpose of the swap. You put in stronger gears to handle more torque, then overload a 'weak point bearing' from a transmission which is rated for much lower torque/horsepower. Short term, it works...but long term? FYI in Japan they cut down the shift fork to fit the earlier tranny, rather than bore-up the casing. I guess they want as much aluminum die-cast supporting the rods as possible. And THAT takes some doing as you have to disassemble the clusters to some extent to remove the rod, chuck it in a lathe, cut the end down, and then reinstall it! Then again, I suppose their logic is 'while it's apart, overhaul it' and therefore turning down the rod is simply another step while the thing is all the way down.

Should be of no surprise, the RB20 was the generational replacement for the L-Series in the model lineup in 1983/84. Same cars, just different engine/tranny.

Looks like Frank driving through the countryside in the Kermit-Green Highroof...

That should not be the case, you have either not enlarged the delivery passage in the block as required, have excessive bearing wear on the bottom end resulting in excessive demand there, or run a pump of insufficient size/spring relief pressure to do it. An Auto-Turbo oil pump will have MORE than enough flow to absolutely FLOOD the top end with a dual lubrication system.So will the stock pump if the bottom end bearings are in decent shape and not throwing off a lot of oil from excessive clearances. I have left off the obvious "the plug is in the back of the cam" as a reason for what should be clear reasoning to everyone.

Yeah, tell me now after I buy something else in China for $10... I guess when this one craps out, I get that one!

Proper Dampers are required on the snout, and that works in conjunction with flywheel/package weight as well. But like John C says: stock engines insomuch as cast pistons and stock (crappy) dampner!

One of those is not what is being discussed, what you describe with clutch disengagement is SEQUENTIAL Supercharging, where one goes into bypass at a point where the other takes over. This discussion is about putting the discharge of one sueprcharger into the other for COMPOUND Supercharging, meaning Turbo 1 produces 5psi which goes into Turbo 2 which boosts it from 5 to 15psi. That would be your first example, but generally it's not a 'stalled' turbo it's drawing air through, it's merely one that is not at boost threshold. In the that scenario the Supercharger is blowing into engine being fed by turbocharger (the most common compound action in this scenario) as this allows HUMONGOUS compressor wheels to be used with realitively high slip from the turbine to compressor meaning the supercharger is geared to give X psi at just off-idle, and progressively goes upwards, but as it's efficiency drops off as the CR on the mechanical devices raises (meaning excessive heat generation) the turbo is starting to 'overfeed' the mechanical supercharger meaning the CR on the second stage drops, as does its' temperature and a compounding effect is noted where a mechanical supercharger giving 5psi (@ 100C IAT) at top rpm now is giving you 45psi at the SAME IAT because the turbo is pumping in 15psi above X000rpms keeping the CR constant and preventing the temp from rising uncontrollably (thanks to that 1st Stage INTERcooler... )(In this application only a first stage intercooler may be neccary to run because the effect of the turbo into the mechanical supercharger is such that the CR being generated by the mechanical unit is not sufficient to require it. If it was employed, that second intercooler under the mechanical Supercharger can be sized for a lower heat rejection as CR remains relatively constant.) This is particularly noticeable in industrial compressors where 1st and 2nd Stage discharge temperatures are in the mid-high 200 F range, while the last stage of compression is discharging air in the high 100's. It means you use larger intercoolers on the 1st and 2nd Stages, and the last stage can be pumped directly into the engine (as is the case with many commercial diesel applications now) the density loss at that temperature many times is not worth the weight or complexity/cost penalty of adding a third intercooler to the stack. Another way to do it is to pump the first turbo uncooled into the second and then cool it, using the mass calculations from the hotter air to size the turbo appropriately to feed it and then just cool it all down afterwards. Knowing 4:1 CR will net you something in the region of 455F you really want to shy away from that kind of approach as it's the kindling point of paper...and when you pump 455F into an aluminum cooler they tend to crack in short order from the extreme thermal cycling.(experience talking here...) I'd shy from that setup.

Looks like that guy treaded the same water as I did with the Turbo Vair, it's got all the high tech goodies from the era on it. But I bought mine from Spearco!

That Eyebolt screwed into the rear bumper hole will lift the whole car off the ground with a strap on it! Similarly, the eyebolt screwed into the top right-hand tranny bolt hole on the back of the block will do similar things to the engine... Security is important, you get that with pad-eyes and proper angles on the chains/straps/ropes you use when lifting. I guess using three guys to lift a block out is now considered 'Beasting' something out... What is it when you don't have any friends and you do it on your own? No head, no intake, no exhaust... That block is a one-man lifting chore then! I guess you must have REALLY been drinking to need three of you to do it! Truthfully, I've wondered with the head off, if you couldn't use a SINGLE pad-eye to lift the block, or block and tranny out. I've never tried a balancing point test on that assembly, and judging from your photo, that front bolt is kinda superfluous. I know my engine lifter does change angles nicely...but a single bolt lifting point...you got to wonder, don't you?

Damn you Pete, more Obsolete Parts I now must possess! I do have a nice SK Turbo Conversion for the L20E though...it has a BOV on it...where's Crowns?

"but some people like the stock nissan EFI systems" /whispering from the shrubbery:/ Some people like having sex with their relatives as well, it gets the job done, but it's never quite right, you know? /sneaks down to the river for his escape.../