Tony D

Well, Ed, I don't exactly know why you would have to "tune" your Webers every weekend---mine were set up once, and other than adjusting idle screw (which usually went right back where it was anyway) when I did a normal tune-up I didn't screw with them for YEARS. So there is something wrong with your setup, and you're missing it. Fix that before putting another system on it, or you will have some hard road ahead when it comes to smoothing out the MS system. You might get 12mpg on a good day with Webers, BTW, if you have a moderate foot. The trick with them is the emulsion tubes and transition port modifications to get a decent transistion. If you lost power with the Webers, my guess is you are pig rich to begin with. Are you wanting to run the Webers with the MS giving you spark control ONLY, or are you going to go back to EFI, and drive it with MS? Again, your wanting to make nasty comments aside, if you clearly stated what you PLAN on doing with the car, instead of giving peicemeal quips we could probably be MUCH more helpful. You say to "read your posts" but damn, dude! Your first post says 280Z. COMMON SENSE would say Stock EFI. We are not telepathic here---you said nothing about Webers. That didn't come till the 9th post in the thread. I'm still confused beause you haven't really CLEARLY said ANYTHING... So let's clarify: What are you DOING, and what are you PLANS---no hidden things here, put it up front so we aren't guessing or making assumptions. What needs to be seriously and clearly addressed... Are you planning on using the EFI going back to the stock or a modified manifold, or the Webers? Are you planning on running IGNITION ONLY--using the MS as a controllable ignition box? If it's the latter, you probably would be cheaper to get a recurved dizzy and have better results than the rather complex path of making a locked down unit to trigger an auxillary spark control box, and driving the igniton that way. I will tell you this, while a programmable ignition will sound good, it's just not really needed on an N/A engine. A recurved dizzy works well, and is the design complement to the Weber Conversion since they don't have vacuum advance. I will agree with the above statement, the programmable ignition is not going to solve your MPG woes. For that, you will need to ditch the webers, and run close to 18:1 AFRs in the two or three lowest MAP bins--with that you will get 30mpg with a 3.9 rearend and an early five speed. (Though to be honest, that is with triple throttle bodies...) But changing the igniton alone? Ain't gonna do nothing appreciable for your mileage.

I gotta say, Superkid, you definately are "in training"! If you did every hairbrained test a customer demanded you will find out VERY quickly you not only waste YOUR time, but the customer who "knows it all" will be JUST as P.O. when it's not fixed at the end of the day. For what the guy says, if he says your Webers are mounted backwards, that's a visual thing---if he SEES IT then there is no reason to do any more till THAT is fixed. I can tell you right now IT'S JETTED WRONG. All the DGV kits were. They are marginal performers, and DO need rejetting, especially on tired old engines---they run rich. And if it's not a smog-legal california kit, I can WARRANT they are jetted FAR too rich. I don't need a scope to tell ME that, nor do I need an exhaust analyzer. Put it on a dyno with a five-gas why don't you? That will run you 150 and HOUR, and be about as usefull. Before telling the technician his job, why not try fixing the MECHANICAL portions of your vehicle first. As a technician, I would NOT put diagnostic meters like the exhaust analyzer on to verify a bad condition till there was a snowball's chance to be repaired. If I saw mechanical problems, I would say they need to be repaired first, before any more in-depth diagnostics were done. What would the scope tell you? That you are firing on each cylinder? What voltage you are firing at? I mean, what is the point of putting it on the scope----what is the car doing that makes you think putting in on a magic box will tell you anything an experienced technican can't figure out by listening, observing, and doing simple tests with his hand tools. This is only common sense. You have to have it mechanically correct, FIRST, then get down to the details. The exhaust analyzer will NOT "tell you what is wrong with your carbs", it will just tell you what he ALREADY KNOWS: They are jetted rich. Instead of coming here complaining about trying to get your car back without paying a guy for the time he has into it---why don't you post the PROBLEMS you are having. Had you done that first, you probably would be $600 richer right now. Or at least have carbs mounted correctly.

I have, and do you remember the scene where he almost finds what he thinks is the car, out in Vegas? Guy at a gas pump: "Hey this car's in Vegas!" Are you sure? It's right hand drive! "Yeah yeah yeah, Candy Apple Metal Flake---this car's in Vegas!" So Luke...uh....Mark goes to Vegas where there is a big "Win This Car" display, and he fights his way to the front of the crowd, and he sees a RHD S-30 Z-CAR done up just as hideously as they did that Corvette and incredulously says: "A DATSUN?!?!?!?!?" At first, it was just a disapointment when I saw it in the theater. Later, when I bought my first Fairlady Z, I found it amusing as hell! It's still funny to me...

JeffP has Crower Rods in his stroker.

search and you will see over and over and over that you don't need a laptop to tune the megasquirt! AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAARRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRGGGGGGGGGGGGGGGGGGGGGGGGHH!

no worries, if you knew what I have kept close-mouthed on in the past to this very day, you would be amazed. You forget I have signed confidentiality agreements binding me from talking about a LOT of things I saw from the years 1999-2002 when I was around some very high-end motorsports development work (peripherally, admittedly, but I knew what I was looking at! LOL)

I swore to gawd I posted Lance's information. There is someone who will build you a cylinder head for around $15,000. If you are unwilling to invest that much, I hesitate to give out his information. The stuff is there in the links if you go backwards from my original sourcing. I just don't want him pestered with a bunch of questions from people who are not going to actually buy the thing from him. Sorry, but I have to use him for some of my stuff, and I don't want him P.O. for me causing him grief with a bunch of callers wasting his time. Yeah, I don't want to sound coarse, but I clicked on two links on that page and found contact information. Please if you aren't serious to that level of commitment don't bother him, I don't need that kind of grief when I go into the shop, and really can't afford for him to be P.O. at me.

Not "Stock", the phrase was "Competition Prepped Stock Rods" the labor for that can be two hours per rod---$100 each, plus what the rod cost initially---that is close to the dollar level where you can get a decent aftermarket rod. For a race engine that was on an almost unlimited budget, in a class that required 'stock components" they used prepped stock rods to around that 600hp level. After that, they outright broke. For longevity reasons below that hp level and where the class rules allowed it (weight is also MAJOR REASON) they went with aftermarket rods.The stockers were simply inspected and replaced frequently. Aftermarket units, not so much so. There will be absolutely no reason to run the three programs in your Megasquirt. The ONLY thing you will get is resolution from the lower boost levels, making the map go from 0 to 21psia for your first example, and 0-28psia for the second one. Now the "race gas" versus "pump gas" would benefit as the advance curves would make a difference. One of the primary reasons to go with aftermarket rods is you can pick a length you want, to accomodate a custom piston with a custom pin height. if you go this far, and are going to have custom pistons made anyway, you may as well go wit hthe rods, they will be uder $1200 more than likely, and you can be sure they are lighter than stock, and probably stronger. If you are doing it, do it right and then don't worry about it. The power will be in the head. Holding it together will be in the bottom end.

"He had his doubts about the longevity of the cam" Don't worry Jeff, those only have to last 23 miles, and afterwards, we can both wear our Red Jackets with pride.... Ssssssh! "Top Secret!"

You guys (ED and GAVIN) are putting words in the mouths of the people answering the questions. neither of you have sufficiently answered any of the questions posed to you about the proposed setup you are running. Let's recap thusfar: What Megasquirt requires is a Crank Referenced Signal that will trigger three events per crankshaft revolution. This can be accomplished through the 81 CAS unit, magnets on the flywheel, magnets on the pulley, or hall effect sensors in similar configuration. If you reference off the cam, to give the same 3 per revolution, you will need six triggered events. This can be accomplished off the stock 82/83 CAS which has a specially splined drive to keep slop to a minimum.As before, six trigger magnets, or paddles on the camshaft with a pickup can also be used. You can also use a stock distributor that has had both the Vacuum and Centrifugal Advance Mechanisims removed and the breaker plate locked to prevent any movement. If you are using the reluctor and pickup in the stock system, you will need to interface through the stock MS Box through an amplifier to shape the signal (HEI Module). This is IN ADDITION to the HEI module you will use to triger the coil for the spark events. I needn't be anything special as there is no dwell issue or high output required like on the one that drives the coil. But points? No, I wouldn't recomend points as the signal is simply not clean enough totrigger the events. If you converted to a pertronix or other breakerless ignition system then you could use it. But for the cost, an 82/83 ZXT CAS would be available. So to sum it all up, POINTS, no. Breakerless, yes, with modifications. If you have N/A, there really is no real need to control spark with the ECU---it's when the turbo kicks in boost when spark control comes in handy. For my wife's 260Z, I went with the MS-n-S on an N/A simply because the ignition system was breaking down, so a conversion to the 82 CAS had more than one advantage. Keep in mind, if you ARE turbo, the extra voltage of the spark flying around in the distributor can cause issues with tower jumping---which is one of the reasons the 81-83 ZXT's have terminals spaced further apart, a rotor that fits the cap tighter, and a rotor with a longer arc for spark jumpoff to a terminal... If you are turbo, and plan on boost above 10-12psi, you woul.d be well served to go with the cap with the wider terminal spacing and not use the N/A dizzy in that application.

Anybody else shocked by the fact that with four hours to go on the auction, the bidding on those USED rockers has gone above $250? Anybody know how much they were new from Malvern when they were being offered?

There is actually a trimpot on the back of the tachometer you can tweak to get it "recalibrated" correctly, but simply adding resistors in series till you get close, THEN using the tweakability trimpot internal to the tach for the final tuning would probably be a better idea... Use several resistors to find the total that gets you close, then see if you can find a single resistor to replace the "package" you assembled. Even if it's only somewhat close, you still have the internal trimpot to make the final adjustments. My Autometer Tach is terribly innacurate below 1100 rpm, but from that point onward, it's dead on. So I live with it, who needs the tach below 1100 anyway?

That was answered pretty clearnly in JeffP's post dealing with the actual ratio they are, and the ramp shape and lobe profile. In short, no. You need a custom ground cam to take advantage of the roller rocker.

Thanks Katman, that was what I thought. I looked in the "Blue Book of How To Modify" and in there it says 4.218, but everyplace other I have cehcked says 4.250" So that measurement of .003 "off spec" is nowhere near you need to be to casue a problem with chain length.

Yeh, L20B rods are a bit long, at 146mm, but they work nicely in an L20A to work the rod ratio up to the stratosphere... Tight Ring Stack and custom pistons, for sure! In Japan, N42's were boosted to over 2 bar routinely using old school technology, so that shouldn't be a problem. As Tim has shown with that Dyno Chart, it's doable... (Gives him a chance to post it again...LOL) With that low a compression ratio, you might want to look into a retarded line-staging scheme to the timing so you can build boost at the line and launch under almost full boost. You will be loosing time unless you get something to spool that baby---man, I wouldn't want to road race that thing, off bost tractability would be like a Yugo... Let us know how it all works out. Good Luck!

Cool, nice shots and looks nice with the MS in there! But... "but we later discovered that it is actually one of the rare Black Pearl Edition Z's - the first Z to come in black." Add to that a disclaimer "In the US Market", they were available in true black on Fairlady Z's in Japan for years before they offered "The Pearl" here! On that never turning off brake light, make sure you are using the correct master cylinder caps---the 77 and 78s had those funky level floats, if they stick or the mag switches go bad you get that. I used ZX caps on my Fairlady to fix that after the P.O. put in a standard, earlier MC in the car. Two outher sources for the light: Handbrake Switch being bad, or the wire being sliced and grounding, and the little switch on the left fenderwell down by the frame rail---not the switch so much, but the exhaust heat making the wire insulation melt and it grounding out... I digress. Hope those ideas get your brake light to go out! Boost On!

I edited. I was thinking 4 1/4", ended up decimalizing 4 1/8". Damn, why can't we all go to the metric system?!?!?!?!?! 108mm?

Oh, and as far as checks, use the FSM, there is a Clutch Plate Thickness specification, a rivet head depth specification, as well as several other checks you can make. If you need the information from the 240mm BW Clutch Assy, I have the FSM for my 83ZXT, and probably can scan and e-mail you the checks and specifications pages--drop me an e-mail and I will get on it if you need it right away.

Don't forget the center THRUST BEARING! Personally, I DISCONNECT the clutch switch on EVERY car I own, including my wife's 2000 Frontier. We existed for DECADES without an "Idiot Interlock" that says to start your car in "N". I can think of nothing more strenuous for a babbit bearing that placing it under FULL LOAD without lubrication, and rapidly accelerating the components. Think about it, that is EXACTLY what you are doing by depressing the clutch and starting the car on a cold morning! Hell, every time you start the car!!! Ever wonder how you can set up endplay tight, and 20K miles later when you check thrust clearances it's changed by a few thousandths? I am a big "put it in N" fan, for a hill I use the E-Brake. On the one car, I can use the line locks, but that ends up being bad for the tires---the rears at least...LOL

Yeah, Brazil's Alcool Programme was highly successful... Advances in electronic technology are solely responsible for gains in efficiency. Without EFI, Ethanol really gets sucked down, is almost impossible to get the car to start in sub-zero temperatures, and it's a continuous fight to keep water out of the fuel system, as ethanol LOVES water! The problem is the energy used to produce ethanol is far more than that of conventional fossil fuels. Matter of fact, most ethanol produced for automotive usage outside the mideast portions of the USA comes from hydrocracked petroleum because it's simply cheaper and more efficiently produced by that means as opposed to terribly inefficient biomass alternatives for base stock production. It has less BTU's, you will always use more per miles travelled than gasoline. It's not the miracle fuel ADM touts it to be, not by a long shot. Living with it as a sole source fuel opens your eyes. I recomend you try it, your eyes will be opened in more ways that one.

Pretty Simple to figure out how much was machined: Take a caliper amd measure from deck to top of the head, measurement is somewhere around 4.250" or there abouts. When checking in the junkyard that is what I chek for, and it hasn't steered me wrong. I usually check the spec before going junkyarding for the day---it's in the Blue Nissan "How to Modify" booklet. That will tell you exactly how much has been removed from the head. As for how mch out of the tensioner---till it pops out. The NISMO catalog formerly had a chain tensioner LIMITER that would stop the thing form popping out, but short of measuring that distance on someone's engine that has one the only thing I can say is so it's stable, doesn't cock, and doesnt' pop out. An L20B set would be WAY too long. 10mm too long! Your tensioner would be popped out if you used one of those. They move out with 30 to 100 thousandths milled off the head, with almost TWICE that, the thing literally slaps all over the place, and I don't think that's what you have.

methanol needs precautions like SS injectors. Ethanol is not nearly as corrosive. I ran a VW bus for a project for almost a year back in 1979. Distilled my own from Sugar Beets. Fuel mileage being "little" worse is an understatement. More like 1/2! I got about 5 to 8mpg as opposed to 12 to 19 with gasoline. The only real difference between the two engines was the flycut on the heads for the compression increase. Same dizzy Bosch 009, just twisted a bit further for running on Ethanol. Methanol (M85) is the stuff that's nasty. Ethanol (E85) isn't that bad, nor is it really requiring of anything special in line of fuel system components.

Yep, that's the "4+2" configuration common from 75-80 or 81...

The funny thing is the Rotary Valve People were not interesting in building a head for a Z-Car, nor with converting an existing example. They are hellbent for election on converting every metropolitan Diesel Bus in the country into a CNG Burning Rotary-Valved powerplant, and simply don't have time for us Hobby-Guys with some coin to experiment... The DEVAS people, on the other hand, more that happily provided a quote, and given the tradeoffs between using a preexisting head, and retrofitting the actuators to it, or redesigning the whole head to use the rotary valves, the retention of current technology is somewhat more palatable as the rotary valve scheme is still fixed and static with regards to the power you get from the thing---the Variable Aspects of the DEVAS system and it's ability to retrofit to the existing cylinder head makes for an interesting conversion. The shutter system you discussed IS EXACTLY what the DEVAS system can do with the EXISTING poppet valves! There really is no reason for a throttle valve when you can control lift, opening time, duration, and rate of opening! Even more interesting is the possibility of using a Modular Headed KA-24 conversion with the DEVAS system giving us better port flow, as well as a crossflow head without the hassle of re-lineboring the cams after sweatbrazing the head sections together.... But we digress. BTW, the Aspin Rotary Valve is a very old concept, still 20th century.... Computer controlled vavles on a pseudo-desmodromic valve arrangement is a modern application of an 18th century idea. Get RID of the cam! (insert photo of red circle with line through it superimposed over camshaft) http://www.profuelmanager.com/camless.html

Over by the Brake Booster! I used a ballast from an 81 or 82 I believe. It was the only one I found that had a true SIX resistor pack, and not the more common 4+2 setup. The 4+2 setup has two plugs to it, and two power wires, but if you strip the wiring cover back far enough, you find the "two" power wores are spliced together to a common point that leads back to the relay. It's a small aluminum box attached to the sheetmetal with two screws. White plug on a short pigtail. It's there! See, I knew you would find it! LOL