Tony D

20 was what I used for most of mine. Power was 12, injectors were 18, if I recall...

Most of the discussion about 'the harmonic' revolves around crank breakage. It's not really a valid concern---like you noted proper balancer installation and running through a critical speed instead of loitering at it for extended period and you should not have a problem with crank breakage. Larger industrial engines experience crank breakage due to harmonics usually in the first critical speed. Cooper GMV 's were good for that, V16 with 3 foot bore, 6 foot stroke...if you operated under load or overloaded at the proper rpm, the result was not nice. That is the crux of the misunderstanding, like you stated JM, people think if you go over that rpm it goes 'boom' and that isn't the case. In fact, by limiting their upper engine rpm range AT the target harmonic you can exacerbate the issue! If you have access to proper vibration sensing equipment, you can ring the crank and see what it's resonant frequency occurs at, and work from there to lessen it's effects. The L28 ran for four seasons+ without incident. Upon teardonw nothing was amiss. The first season, while runnning a setup that had a power peak at 7500rpms, Andy did run across the harmonic dampner nut loose at the end of a run...literally fell out into his hand when he checked it! The damage was done, so he welded the nut to the crank and we ran it to the end of the season. We replaced the crank that offseason, and changed to the EFI setup with a power peak at 8250, and then started shifting around 8500 or so, and went three seasons without another incident related to the crankshaft...the piston pins walked and kissed the cylinder walls...but nothing on the crank. "Never seen pressed-in pins do that before!" Key to any harmonic is to pass through it as fast as possible to minimise the chance for resonance.

"Everyone"? Our L28 in the Bonneville Car runs at 8500. The L20A currently in the vehicle for G/PRO Competiton is shifted at 93-9500 rpms. And these are 'conservative endurance' builds believe it or not! In Japan, in the mid 80's, a 9K L-Engine was what you wanted if you were up front of the competitors. Non-Crossflow Carburetted Blowthrough (50mm Mikuinis) running twin turbos were routinely street driven with 400+Kw. I personally witnessed several passes at a local dyno in Okinawa in 1986 where the car consistently put down 444Kw! This was on the non-crossflow head, and having a redoline/shiftopoint (like that Japanese Accent there?) of between 9 and 9200 rpms. The crank harmonic discussed online is more related to the early cranks that were not properly counterweighted. Oh, and both the cranks in the Bonneville Car: Pulled out of the junkyard, polished journals, magnafluxed, and bobweight balanced. No polishing of the counterweights, no knife-edging, no cryotreating. Just a standard prep and good balance on a 163,000 miles L28 Crank. Same goes for the L20A Crank: only it had about 105,000 Km on it. Standard timing chain set, nothing fancy there either! "The 7500 Harmonic" is overblown and terribly misunderstood. And I'll agree with mortensen on the degradation of the thread---too much bad info bubbles forth far too easily on this topic, the referenced link is a good example of the swarf that gets thrown about regarding it. Are all the "Tool Shed" posts blocked from being 'searched' from the general search engine?

GM TBI Injectors, you say? www.sidedrafttbi.com I already contacted them about HS6 and HS4 compatibility. "It's in the works, HS4 this winter, HS6 before then, probably around Thanksgiving."

I works, but if you are in California, you will have a time finding a place to do it. It was once easy to have done for under $500... Now.... "Thank your legislators for protecting the environment so children can eat five pounds of sand per day, every day, for five years...and not have any cancerous effects AT ALL!" Woo Hoo. If you find a place to do it, let me know! And how much they charge as well!

Ever take a look at the castings closely? Hitachi, like Yamaha, has a very distinctive mark. Even with 'Nissan' throttle bodies you can find 'The Distinctive Trademark of Hitachi' on some of them! Many times it's a factor of who did the design work. Nissan may have done the work, as they did have a large foundry, but some of it morphed into Fuji Heavy (ever notice Subie Diffs are R180's and R200's? 'Datsun Parts' to us, but "Fuji Heavy" componentry available to anybody who wanted to buy in sufficient numbers.) Jaguar used Saginaw Steering Gear components made at Plant 2 in Saginaw Michigan for years. Matter of fact, there was a LOT of 'secret product interchange' on componentry. Johnson Controls makes seats for Ford...Dash Assemblies for Nissan and Ford, amongst others... Some people do one thing, do it well, and everybody beats a path to their door. Oh, and 'I have ways' of finding this stuff out. LOL

Yep! No 280Z's outside North American Market. And a 280C Coupe or Sedan would probably be like finding hen's teeth... Probably the best way would be to follow the thread on the converted SU to EFI thread that used twin Throttle Bodies in place of the carburettors. With that, any set of injectors would work if you machined the existing manifold, then you find whatever you need for an air door---putting a plenum on the SU Runners and any Throttle Body from a comparable sized engine that is locally available would work.. From there yes, fuel rail, fuel pump, some way to make sure the fuel pump stays flooded in fuel...so surge tank or swirl pot, injectors, air temp sensor, water temp sensor...that should do it after wiring harness is fabbed up. Most of the stuff can be salvaged from locally available EFI Cars, and the Megasquirt Calibrated to work with what you can find. As for the 280Z comment...what can you say to him? "Buska Paa!" SSSSSSSSSSSSSSSH! Blobber, it's our secret...LOL Even if I spelled it wrong, phonetically, it's right eh?

I wonder if that is the one that dissapeared with the Elusive Mr. Les Heath? LOL

Yeah, JeffP did the Nisstune thing...45 minutes on N/A portion, then another 45 minutes on Boost Load Scalars. Making passes from 80 to 120mph while trying to adjust the AFR is just not practical on the street.

EXCELLENT POINT NIGEL! This is EXACTLY the phenomenon I was talking about in the 'build a nice surge tank' post! Just because you have a 280 Tank does not mean you can't run dry or that you don't require an external surge tank! I have said it before, even on triple Mikuini Cars, the Datsun Competition Manual used two fuel pumps and a surge tank to fuel N/A 240's in competition! The surge tank is more of an issue to solve cornering problems with fuel starvation, and it's combatted by making a vessel taller than it is wide so that during cornering the outlet (pump suction) is always flooded. The nice thing about the 280 Tank is that for a normally driven street car, it will perform satisfactorily for most of the people out there in daily driven activities. If you are racing, a Surge Tank is ALWAYS a good idea, EFI OR N/A!

That would be a welcome 'gloat post' at another site on this subject! LOL As far as materials goes, meh...that's a wash. It's having the damn bender and the labor time to weld one up from pieces that is the 'competitive' issue. On an S30, the system isn't nearly as complex as an S130, but if it's a one-piece from the tranny junction to the muffler out back (downpipe separate) I can see that price. Doing it from bends you cut and piece together, and buying the tubing, doing it yourself that way will kill a day...so the price I would compare to is that in my case. Many times if you split it so they can run the tubes in the machine and get the angles correct in two separate bends it's usually cheaper. For a car that will have the tranny removed regularly (no aspersions, just something to think about) flanging to the rear of the tranny makes for lower costs in bending, and for maintenance access later. FYI, the Trust?GReddy exhausts are flanged at the downpipe near the engine/tranny flange, then again rearward of the tranny. This may be for shipment or packaging, but having flat flanges at the rear of the tranny makes dropping it a snap. 6 M10 bolts and that whole section is out of the way! We all want PHOTOS of the system when it's done! Mandrel 3" Gaaaarrrrgh!

You would save the weight of the tubing that you removed...what is your goal anyway? What are you after? Is the cannister suspect in a malfunction, are you troubleshooting, what do you expect to gain by the removal---why do you want to remove it?

LOL, there are more straight-six mustangs in one year than total domestic production of the S30 series from 69-77! You underestimate the interest in domestic fare in the USA...though I have never heard of a four valver for the Inline Six---anybody for a 5.0L Inline Six Four Valve head? Nissan destroyed almost everything to do with the early Z Cars during 'the turmoil' in the 80's... Datsun was a Baaaaad word then! Datsun didn't make the head anyway, I suspect Hitachi did it...or Fuji Heavy...

When they have a title, they sell complete. When they don't have a title, they figure selling as parts is 'the only option'... Like peddling stolen components is any different than selling the car as a whole anyway... Not casting aspersions, just an observation of the uninitiated. In parts, the car is worth more, anyway.

Wow, seeing the two of them side by side really indicates some visible differences. Guess that 'shortness' has to do with the bumper shocks and extra shielding they put around the mufflers on the EFI cars... Anybody got some side by side shots of the 260 tank next to the 280? I have also swapped 260 tanks into 240's using the longer bolts...and from what I recalled the external dimensions were similar to the 240/280 tank comparo as shown above. On the 260 to 280 swap as I recall, all I did was back the nuts on the 'j' bolts out further to make the tank slip in, so the 260/280 tank may be external dimensional clones, the only difference being the pickups and possibly the baffling internally... BTW, the second sensor on the 280 tank sender unit is a capacitance unit that lights the red 'low fuel' light in the gas gauge on the later cars. A nice feature if you're like me, and know "I can go 72 miles from the time the light turns on in the Truck"... Makes a difference when Eherenberg is only 68 miles away, and that simply crossing the border from Blythe to Exit 1 on the Arizona Side means gas for 30 cents a gallon cheaper! LOL Great Photos, BTW. That makes explanations much easier!

Nice!

V8 Carburettor Fuel Pumps I have seen mechanical fuel pumps used to flood the electrical pumps' tank...

Yeah, CO2 will work to dessicate it as well, it's -110, pretty dry! The key is hot gas has more capability to hold water, than cold gas. The cold gas will be 100% Relative Humidity of -110F (for CO2-which is not much water carrying capability at all---it's dry enough to be used in alcohol to dessicate A/C systems in the old days, but that's another discussion) but then heat that same gas to 100Degrees, and it has a R/H of like 1%---meaning it will be able to actually carry out much more water vapor in the purge stream. Basically air can do the same thing---heat your air to 350F, and the air you had in the oven that started at 75 degree 100% RH will be maybe 1% R/H at 350 degrees. That hot air has a great carrying capability to carry the moisture out of the tank, out the purge holes to elsewhere where it will dissipate or condense. Same thing as condensation in an exhaust pipe. As the exhaust cools, it's capability to hold water decreases, and the liquids condense out. Running the engine speed up gets that hot hot hot gas to the tailpipe where it is still less than say 10% R/H, but upon dissipating in the atmosphere and cooling you condense out side the tailpipe. Hot goes out carrying water. If you heat the tank it's similar, but having a warmed cryogenically produced gas to carry out the moisture will be more effective than simply heating it. Back to the Surge Tank Design Discussion, I mentioned the 42" tall tanks as an extreme example. They weren't more than 4" in diameter, so that's about a 10:1Ratio. A 2" diameter pipe would have similar separation at only 20" tall. The big thing to bring away is the taller is it, the better it can separate any air that eventually manages to get into it---and the key to keeping it flooded is to make that return line pass through the surge tank on the way back to the main tank. Someone used a Fish Aquarium Filter Housing---I thought it was brilliant! Matter of fact I helped install one, and damned if it didn't look like it was MADE to house a fuel pump! Anything that is 'drill a few holes and use it' is eminently efficient, simply from a work output standpoint. I'm all for ease of construction, absolutely! BTW, this meshes nicely as a side factoid about the Accumulator/Dryers form AC systems. When they are "Rebuilt" many times they are simply baked at 350+ for three hours. This will dry out totally the Activated Alumina or Silica Gel used in them. As long as it gets corked up well, it will not adsorb any water from the atmosphere. This is the same material that is in compressed air dryers---and those are either regenerated by heating the beds when moisture saturated and then purging them with a 'polishing airflow' from the downstream side of the dryer to bring the beds up to room temperature. Or you can simply 'purge' the saturated tower with about 15% of the output flow from the downstream side of the dryer---and that -40 or -110 degree air will suck out that moisture from the beads and take it out the vent to atmosphere.

NO! Don't put LN2 into the tank, the rapid expansion and chilling may dessicate the tank but the cooling (if corked decently) can suck the tank down like a beercan and will definately frost the exterior and cause moisture formation in just about any climate! Besides, it's not needed. A good purge will dry it out, and then if Argon follows it will work nicely for welding without using too much gas. But LN2 on the sound deadening would be KILLER! If you have access to the gas at cost, to enhance the dessication of the tank you can make a 'preheater coil' of stainless steel (I guess you could use copper as well)---loop a 1/4" line several times around a small diameter object and run a flame in the center of it from a MAPP or Propane torch. The 'dryness' of the N2 from the bottle will be inanced by the increase in the temperature, allowing it to suck up more moisture and carry it out of the tank. We are talking a fairly low flow rate if you only use a couple of coils---a more densely cpacked coil will of course allow the gas to be heated more efficiently. Hot Gas Purging is a better idea than cool gas purging. Usually this is to make sure no gasoline residues remain, but in this case we're pulling water out. Chances are you will do all your modifications, flush it with acid, dry it out, and then slosh it with the tank coating befroe reinstallation. Purging before welding was the primary focus of my original post, dessication before sloshing may not be required if they use an alcohol-based slushing compound (some aircraft types)---if this is the case, make sure it is compatible with current fuel stocks. I know Aircraft Spruce had an issue with their original compounds when they started oxygenating with Alcohols, and the tank slushing compounds ( some times in place for 15-20+ years!) started coming up due to the alcohol present in the new gasoline formulations. They came out with a new formulation that is not alcohol soluable. Which brings us to dessication for po' folks: If you have 99% Alcohol, splash some in the tank, and drain it out...let it sit in the sun. As a dessication process before slushing (NOT before welding!) that is fairly efficient as the alcohol will suck up the water, and will evaporate without leaving a residue with application of minimal heat.

It WILL act up with the stock FPR in there, there is too much fuel with the 300cc injectors, about 25% too much. Either lower your fuel pressure 25% (not a good idea) or do the AFM Rig to lean it out while on the flapper. Problem with the Bosch System is you are better off keeping stock injectors and playing with a Rising Rate Fuel Pressure Regulator than you are installing bigger injectors. With stock injectors, off-boost drivability remians as stock, and under boost additional fueling is taken care of by raised fuel pressure. I'd get Megasquirt ordered now, and just start reading on how to tune it. You will be better off in the long run! With 300CC injectors you will be in the area of 75-80 psi requirement at 13psi of boost. If they were stock 280ZX injectors you would be in the range of 100psi and about maxed out. Hope you got a good fuel pump! You didn't mention it, and if it's a stocker, you will stangnate the fuel flow at around 60psi when the internal relief valve lifts---then you run lean and go 'boom'!

Yes, if you look at the J-Bolts that secure the tank in the 280, you will see there is one that is substantially longer than the other. Two of those and you are set as far as getting it to work.

If you purge from nitrogen bottles, there is no reason for heat to be applied, the N2 is superr-dehydrated, and if you cork the fittings and leave only a small pin prick for the N2 to escape (fill through the 1/4" top vent, and off gas through all other openings through small holes) any moisture in the tank, and the pores of the metal will be desiccated through the N2 passing over the metal, and out the vent holes. You can leave the N2 on the tank while welding and the backsides of the weld will look really nice as well! "Inert Gas Purge" is what you really want to do, but most people don't have N2 Available (or didn't) at the time, and the exhaust gas purge was a pretty common thing to to with the old timers. With cars running less than 8% O2 content in the exhaust today after the catalyst, it definately will not support combustion, and the heat helps liberate any solvents from the metal as well. Argon would work, but is much more expensive than N2. Any cryogenically-derived gas will have low/zero moisture content by virtue of the distillation process. This stuff is made a -200 Degrees F and colder, ain't no moisture content there! It went away 232 degrees ago! What you worry about in cryo plants is CO2 plugs as it turns to liquid, and then freezes solid at only -110F, and that can ruin your day trying to cool down a box for N2 or O2...Nothing like taking a rosebud torch into rockwool to 'melt out' a CO2 Ice Plug in an O2 enriched environment! LOL

Luckily I have a 1-ton rated Gantry at the house, and can use large nylon slings to lift the body... Or the Forklift, if I ever get this damn concrete contractor to come out and give me a firm price! Dug it out a month ago, got all the stakes in...but no way am I doing THIS much concrete. 4 yards, maybe...not this much!

Well, I didn't say it was cheap. When I worked on the landfill I had access to that size P.E. piping, as well as a MacElroy Fusion Machine...You want to talk about 'abusing the system' I had the best high-impact storage vessels on the planet, Sch 80 HDPE Piping with threaded covers! It's one of the reasons I bug people about getting mine back nowadays, those Black P.E. storage cases I made went away 10 years ago, and never came back! I know who they went to, and some day I WILL be in the neighborhood and RECLAIM THEM! The large military surplus containers I used in the past were Rocket Boxes. Could fit a whole intake system in one, and they have nice preformed foam cradles that work great if you wrap cardboard around the crank throws to make them a more manageable 'round' shape. You can fit three-four cranks in a standard rocket box. They are just the right length for L6 Cranks and Cams, and heads if you take the towers off. My supply of those ended when I was no longer attached to the Munitions Maintenance Squadron back in 86... Bummer! More wonderful 'endless supply' items that I gave away and now lament... I'll also add that during my time with Cooper Industries when we would do up Turbochargers for Overseas, we coated the internals by flowing STP through the oil passages. I have found that using STP Raw makes for a VERY persistent coating when undistrubed, for that 'rotational' idea GV had, that may work so you only have to rotate them semi-annually. I can get real Cosmoline, and a couple of good coats and corking it up while still volatile seems to keep the corrosion at bay for great periods of time with minimal fuss. Heck, let's pack a Jeep in it! LOL

To dry mine, and in homage to my Germanic roots, I attached a 'gopher gasser hose' to the tailpipe of the VW, and pumped the tank full of exhaust gas...nice warm exhaust gas (leave out the sender, pump it in through the tank filler, or sender hole). Tank may get some condensation in it if the hose is relatively short and the gas is really hot, but you can't argue that it gets a nice, complete inert-gas purge before any welding repairs are done, and since it heats up nicely any moisture inside is dried out pretty quickly. This is how we did it when I was in Body Class 20+ years ago... Still do it that way today.