HS30-H

Yes Ash - they are all in Japan. Mind you, that's closer to you than it is to me! You can still get replicas of the "Works" Type "A" and "B" aerodynamic body kits in Japan. In the pictures above, Shun Koike's car has a "Type A" kit ( notice the shape of the front spoiler on the G nose ) and the genuine Works ZR ( the appelation that they gave to the race version of the ZG ) is wearing the full "Type B" with the different front spoiler, wider arches and tall three-piece rear spoiler. Both kits are still available as replicas in Japan. Alan T.

Hi George, Just like Alfadog says - its probably the synchros in your gearbox that are getting tired. If you don't know what these are - basically they are small toothed rings which ensure that your gears mesh together smoothly as you change gear. They wear out eventually, and the only way to fix it is to replace them - which means a full transmission strip down. Meeting this problem, I have noticed that may people start looking around for a good used transmission to swap in. This will almost certainly have the same problems, or will eventually develop them - so its a false economy. If you replace the synchro rings and freshen up the 'box with a few new bearings and shifter bushes, you will not believe the difference. The transmission is one of the main places that the driver interfaces with the mechanism of the car, and if its working right it is a real joy to use. I've driven quite a few "other people's" Z cars, and it is amazing how many of them are soldiering on with a tired and baulky transmission that makes it pain to drive the car. Mind you, you have not got a synchro on reverse gear - so that will always be a slow shift. If you can't get it to engage reverse smoothly ( without the crunch / graunch ) even after doing it slowly and deliberately, then you may have a clutch or clutch operating system issue after all. Did it start doing this suddenly, or has it gradually got worse? Alan T.

Hi Saint, 90mph? Is this part of the break-in procedure for your rebuilt engine? I think you should be taking it a bit easier for the first few hundred miles at least........... Pinning down the whine / vibration will be quite hard on a completely restored car that you never drove before the resto. - you do not know the history of some of the components that have not been replaced. However, the low pitched whine is probably the diff. If it was the transmission you would be able to hear it more beside you rather than behind you - so where is it coming from? Since your car started life as an HLS30 you might very well still have a diff. ratio that does not suit your conversion to a 5-speed box. A 3.9 ratio would probably be better - so this might be a good chance to fit one. This should be easy to find here in the UK - but I have one that is a "known quantity" if you get stumped for one. The vibration could be the propshaft or indeed any other rotating component, but the prop and driveshafts would be the most likely culprits seeing as your wheels and tyres are brand spanking new and have just been balanced.......... These cars are supposed to be smooth as anything when cruising in top gear - so there is definitely an issue with yours. However, after taking it completely apart and putting it back together you will have to expect some niggles like this. Don't get too upset, and it will all be sortable in the end. Good luck, Alan T.

Hi Ashley, I'll write out the ratios and e-mail them you direct. That custom-built box with " any ratios you want" sounds a bit too good to be true. Where will he be getting the gears from?! There's a fair bit of mix-and-matching that you can do to come up with something close to a close-ratio overdrive box, but its not unlimited and I think he may be exaggerating somewhat......... Of course, if he really CAN come up with something like the Option direct-top ratios then it will be good. Do remember that the best choice for a circuit car is NOT going to be anything with an overdriven fifth gear, and is going to have that dogleg first pattern that will allow you to use second to fifth gears in a conventional "H" gate ( must faster and less easy to fumble a shift in ). Trouble is, this would demand the different rails and selectors of the dogleg box - which are all but unobtainable................ Alan T.

Here's a side-on pic. of the Works 240ZR at the 2001 event, post restoration.

And here it is with the bonnet on ( they don't call them "hoods" in Japan..........

Oops, photo dropped off.....

Here's Mr Abe's car from the front three quarter. The sunlight was a bit strong on the day, but the car was part shaded, so it was difficult to get a good shot in the pits. That black line near the cowl is indeed ( as 2Many said ) the rubber sealing strip, and is not any kind of bar or any other device. The airbox on the carbs is a genuine Works type ( supplied by Mr Matsui of NP35 ) and they were made from a pressed fibre-board kind of material. The Works race cars had a couple of channels made from the same kind of material that funnelled cool air towards the inlet. This car is roughly in the mid-1970 season spec. - just before the aerodynamic parts debuted, but already with the "Overfenders" and the rad panel sheetmetal ( of which there were many versions ).

Here's a picture of Shun Koike's car on track at the 2000 event. The driver is Kazuyoshi Hoshino, who drove these cars for the Works team as one of the so-called "Seven Samurai" core of Works Nissan drivers from the early 1970's.

The photos were taken at the NISMO FESTIVAL events at Fuji Speedway - but they are from two different years; the 2000 and 2001 events. The red car ( no.31 ) is a replica of a "Works" 240Z racer, and is owned by Mr Abe. My good friend Mr Matsui of NP35 built the engine for it, and the body was put together by Mr Shun Koike - who I am also proud to call a friend. Shun owns the no.9 car in the photos - which is a replica of another "Works" 240ZR, this time with the full "Type B" Works aerodynamic kit and the hen's-teeth-rare Works 4-spoke magnesium wheels. Mr Matsui also built the engine for that car, and I can tell you that they are both real screamers. Both Shun and Mr Abe are part of a small core of Z enthusiasts in Japan who are after my own heart; they are nuts about the early period race cars ( especially the Works cars ) and they collect the appropriate parts of the period. Sadly, they are forced to use some parts and some specs. on their cars that are not "period" correct - mainly due to safety requirements. If they were not subject to these rules than the cars would be even more accurate replicas of the real thing. The car with the no.23 IS the Real Thing, and the photo was taken at the 2000 event - when Nissan wheeled out the car to show in the pits and not run. It is nothing less than a full Works-spec. 240ZR ( like a lot of these later Works race cars it was based on a later spec. of bodyshell from about 1974, but was still called a "240ZR" ) complete with LY "Crossflow" engine in carburated spec. At the time of the photo, it was in the condition that it had been in for the last 25 years or so; unrestored but with loads of lovely patina and pretty much all of the correct period parts. This car was campaigned in a few races and then became a Test car for the Works "Omori" ( Nissan Competition HQ in Tokyo ) race team, and was also used at the Nissan Racing School, based at FUJI, where they used to coach young Works drivers. For the 2001 event, NISMO decided to "restore" the car - with what I think was too much of a heavy hand. They completely pulled it apart and went through it - chucking away many of the period parts and replacing them with modern equivalents ( especially the rads, seats and fuel tank ). These look jarringly modern and I think they spoil the feel of the car. They even decided not to use the four-spoke Mags and used modern Watanabes instead ( for safety reasons, I guess ).The new paint is pretty much correct for the car when it was in its first season of Works use, though. Here's a picture of the engine bay on the genuine car, which I took in the pits at the 2001 event;

Hi Ash, The following information on Nissan's early 1970's "Option" sports / race transmissions might be of interest to you: *32010-N3130 "Close Ratio Overdrive" *32010-N3030 "Wide Ratio Overdrive" *32010-N3220 "Option 1 Race Transmission" *32010-N3221 "Option 2 Race Transmission" *32010-N3222 "Option 3 Race Transmission" *32010-N3201 " Rally Transmission" All the above were based on the FS5C71B / F5C71B "Bent Stick" boxes, and the Options 1,2,3 & Rally type all had "Direct Fifth" 1:1 top gears ( sometimes called the "Direct Top" or "Dogleg" boxes ). These are great for the racer, as you don't spend time going in and out of fifth gear on its dogleg with the danger of wrong-slotting reverse. Once you are out of first gear you have a conventional H pattern gate for second to fifth gears, which is quite handy on the track. The lack of overdrive is not a problem on a proper race car, and can be adjusted-for with a judicious rear-end ratio choice. Most of the Option 1,2 & 3 transmissions ended up in the USA, and are now very hard to find in good used condition ( don't bother trying to find a new one ). These Direct Fifth boxes have quite a few differences internally to the "stock" B type boxes, and the selector forks and rails are now all but unobtainable. I can give you a list of the ratios in all the above boxes, which are quite interesting - but a bit longwinded to post up here. Let me know if you need it. QUAIFE will be a bit of a waste of time for you to call I'm afraid; they used to stock a super-wide straight-cut gear set for the B boxes ( they listed it as a 240RS part ) but they have not made these for a few years now. They don't seem to be very interested in making any more either. You can't bolt in the 240RS box complete as it had a different bellhousing that would leave the trans. about 40 degrees from vertical if you bolted it to an L6. Looking at your car, it seems to me that you might be pretty much unhampered by rules and regs. - in which case you might like to investigate some of the boxes from 2WD Skylines that can be made to fit with a bit of engineering nous. Good luck, Alan T.

Hi Z-Voit, That kind of post is pretty much guaranteed to get my attention ( as long as I'm looking in, that is ). As far as I know ( and only the Pope is infallible ) Nissan / Datsun never tried to "soup" any of their race cars in the '60's and '70's. I also don't know of any road cars that they tried to supercharge in the same era, but they might have tried it on some obscure Home-market commercials for all I know. Pretty much most of their induction-side research went on perfecting the fuel injection and engine management systems on the race cars. That's why they were able to jump ahead of their competitors when they applied what they had learned to forced-induction systems. Toyota were always the forced-induction pioneers in Japan ( not forgetting Mazda who were a little behind them ) and Nissan never really got going on turbos until the Eighties. Once they got into them, they really did do it much better than everyone else. However, it was the aftermarket and street-tuning world where most of the really effective research went on.......... I remember HKS used to sell a supercharger kit ( a proper "everything you need" bolt-on job ) for the L28 engine in the early 1980's in Japan. I seem to remember them also offering a bolt-on supercharger kit too around the same period, and I will have to have a dig into my literature collection to see if I can find any photos to scan and post up. That's an interesting challenge for the coming week.......... Why, are you looking for some "free" horsepower?!? Alan T.

Mike, If you got a new set of 40PHH Mikunis ( including manifold and linkage? ) for $600 then it really was the deal of a lifetime........ I am quite often dismayed when people seem to think that the prices for these kinds of parts should be cheaper and cheaper. Japan is one of the most expensive countries in the world ( have a look and see how much your local currency exchange-rates against the mighty Yen ) and the workers there do not get paid peanuts. I have told people before that, contrary to what they seem to believe, Japan is NOT a third world country. In fact, if you buy anything from Japan it SHOULD be really quite expensive compared to your home-grown product. The fact is that they adjust the prices to suit the local markets - so the "new" price of the Mikuni carbs that you can still see advertised at companies like Courtesy Nissan in the USA are in fact CHEAPER than the retail price of the equivalent parts in Japan when they were current. As far as I am concerned, anything made in Japan is pretty "exotic" ( its made on the other side of the world to me ) and I can understand if it works out expensive ( although I'm not all that happy about it! ). I really don't think that you could compare the price of a set of triple side-draught Mikunis to a Holley four-barrel ( or even two Double Pumpers.... ) on a like-for-like basis. The set in Guus's photos look pretty cherry to me ( for a used set ) and that is a GOOD manifold and linkage too ( some aftermarket linkages are laughable ) - so I think that the price of $1500 might not be unachievable. Its a good bargaining point to start out from, and here in Europe we have rules and regulations in some race series ( EG - the F.I.A. homologation regs ) that will not allow anything other than the Mikunis for a period-correct S30-series Z race car. Remember, they are in Europe and they are going to be slightly more expensive than a set that comes up for grabs in the States......... Now, if they really WERE "50's", we would be talking about more than $1500.

Guus, That's a set of triple 44PHH Mikunis in the photos. The 50PHH are quite a different shape altogether. Looks like a nice set with the correct trumpets and everything, and its a shame you did not see these before you got that other set in from the States, eh? Regards, Alan T.

Like anything new, its going to take me some time to get used to the new look ( I was still learning how to use the old one ). One thing bugs me though; that "Classic Zcar Club" ident / banner thing at the top left of the page. I would have thought that a bone-stock and non "customised" car would have been more appropriate than ( what seems to be ) a UK-market HS30 with a colour-coded air dam / spoiler, plastic colour-coded mirrors and the god-awful UK-law compliant front turn signal indicators ( which always raise a big laugh in Japan ). No disrespect to the owner of said car, but wouldn't a "fresh from the factory" looking car be more appropriate? If its going to be a modified car, then surely a "period" modified look would be more appropriate? Whine whine moan moan, Alan T.

Ah Enrique - a voice of reason in the wilderness........... We have the "Concours" competitions over here in the UK too ( makes me laugh when they call them "Concourse" ) and its quite apparent it gets like a sickness with them. As you pointed out, many of the cars become OVER restored - as the owners aim seems to change from total originality to just getting points in the competition. Don't get me wrong; I think its well worth trying to get a resto-job as original as possible - as long as the data, knowledge and parts are out there.That's probably possible for a Porsche 356 or Hemi Coronet, as the data is out there and its pretty much accepted as correct. My gripe with this kind of thing in relation to the S30-series Z is that in many cases the knowledge is NOT out there, and many of the parts are not out there either. Anybody who thinks they can tell you with 100% certainty what a particular model of Z should look like is really kidding themselves. There will certainly be people who remember what the cars looked like when they arrived off the boat ( especially the people who sold and maintained them when new ) but I don't trust 33 year old memories either. I think I have a fairly good knowledge of the particular area of the S30-series Z car that I happen to be enthusiastic about - mainly the Factory Race and Rally cars and the Japanese "Home" market models - but there are ENORMOUS gaps in this knowledge, and I might as well be studying the artifacts of an ancient civilisation when I try to delve into the history of it all. Talking to people in Japan who were "there" on the Factory floor, or working with the race teams at the time, has just made it clearer to me that it is probably now much too late for Nissan / Datsun or anybody else to get the full story and all the facts down for posterity. In comparison, restoring a 1940's Delahaye / Bentley Continental "R" / Maserati Birdcage / Porsche 911R or any other exotic you care to mention is a BREEZE compared to getting it "right" for an early S30-series Z. There is also more literature and first-hand knowledge out there for them too. Its ironic to think that some of the most successful mass-produced Twentieth Century icons have less accurately-researched and complete history than the famously unsuccessful "one-offs" of the same period............... I also think its now becoming clear that the "unitary construction" cars of the late sixties onwards were built once, and taking them apart kills many of the original parts - stopping them from being re-used accurately. You can't re-furb and fabricate on these cars like you can on earlier stuff. Over the last few years I have been actively seeking out more and more genuine NOS and good-condition original parts to keep and trade with. I am also a long-term fan of "patina", and I really do not like to see those "100 Point" resto. jobs that get everything much cheesier than it ever was when it left the factory. My car has stone-chips, tarnished plated parts ( they were tarnished when the factory bolted them on! ) and chipped windows. It also has a life, and I let it live it when I get the opportunity; it does a fair few miles on the track every year ( I'm still fiddling with it and learning how to drive it fast ). If that causes "patina" then I'm happy with it. I was asked to join a "Concours" competition whilst at a Japanese-car show here in the UK a few months ago. I declined the offer, not because I thought I would not win ( I'd lose points for the flysquash! ) but because I did not want to be "judged" by people who know next to nothing about my car. I'm not trying to be elitist or snobby - but how would they be able to judge the originality or otherwise of something that they have no knowledge of? Half of them think my car should have an L20 in it.............. Alan T.

Hi Guus, Sorry for the late reply, but September is a busy month at work for me. I think the setup looks good - but you will certainly want to clean them right out and treat them to a genuine Mikuni gasket / rebuild kit - they look pretty cruddy. The linkages might be a bit tired too. Don't be too ambitious and try to disassemble them completely ( for example - don't try to take the butterflies off of their spindles ) as you probably don't need to do this. I would take out all the jets, the auxiliary venturis and the main venturis themselves, then the accelerator pumps ( you get new accelerator pump diaphragms in the rebuid set - and these are a "must do" ). You will probably have to detatch the floats from the top covers to put a new gasket on - so be sure not to mess up the float level settings if it can be avoided. Otherwise its all quite straightforward. Judging by the standard of the rest of your car, you might be tempted to clean them up so that they look "new". In my opinion this would be a mistake, as the alloy on the earlier types used to dull down quite quickly and take on a nice patina. If you try to shine them up it will spoil them - so I would just try to clean them chemically with no rubbing ( except with a toothbrush or something soft ) to leave a nice greyish coloured finish. You might need to blast clean the manifold, in which case I would recommend vapour blasting or similar ( something that will not open up the surface too much ). Seeing as your car is a replica of the Monte spec. rally car - will you be running air cleaners? I am wondering if the set that you have bought actually has the Mikuni "Air Horns" / Trumpets inside those air cleaners ( maybe not? ). They sure sound great without the aircleaners on. PLEASE do not fit a set of K&N or other "modern" aircleaners to these carbs on YOUR car - they would look quite incongruous! If you have any queries on jet sizes or anything, please let me know. You should ( might ) find the Mikuni factory labels / stickers are still on the carb bodies ( which would identify the type clearly ) - but if not, measure the size of the hole at the rear of the carb where it joins the manifold. That will tell you the size is either 40mm or 44mm. If you need any spares, let me know. Good luck! Alan T.

Laffeux makes some good points there.......... Its well known in Japan that most production changes on the S30-series Z production line were quite "fluid", and in fact there was almost no "cut-off" VIN number where a certain component or specification changed from "old" to "new". A Japanese Z production-line worker I met out there told me that they would quite often "test" fit new spec. components on a few cars at certain times of the day - just to get a feel for how they were working and if there were going to be any problems with them. This even applied to sheetmetal sections of the bodyshell. The truth is that there will be NO firm date or VIN number where one spec. or type becomes another. There was always a grey area of at least a few cars, and in some cases it was a little bit more than a few................ I'm sorry to say it once again ( OK - I know this is a mostly USA-subscribed site, and so is "Z-Home", even though I thought the home of the Z was in Japan.... ) but this fixation with "Series 1" and "Series 2" etc etc is entirely an American phenomenon. It must be a habit that you have fallen into just because you were trying to make sense of spec. changes and put a label on them. The Japanese have never described any spec. changes or model changes in this way - except where owners have picked it up from American-based books / magazines / websites. They are much more pragmatic about the differences than this, and the more informed Japanese Z enthusiasts know that changeovers were gradual ( even though it might seem that they conform to a "plan" ). Whenever I discuss these cars with any Japanese Z enthusiasts, we never use any terms such as "Series 1" or whatever; all that matters is the Chassis Number / VIN, the model type, and the approximate date of manufacture. We then talk about the exact spec. - and this clears up what the features of the car actually are. Both sides appreciate that the early Z production line was fairly chaotic, and that there was not necessarily any hard and fast rule to anything. I must say that the whole "Model Year" thing is just Dealer-Speak nonsense; its quite understandable that a dealer would want to convince a customer that the car he is trying to sell him is the latest type and hot off the line. Thats how this whole Model Year thing came about. The only thing that matters when discussing specs. and model types of S30-series Z cars is the date that they came off the production line. The American fixation with Model Year is a red herring. Alan T.

They already cloned me - where do you think Pee Wee Herman came from?

Try contacting MIKUNI AMERICA CORP. - the last I heard they were in CA. You are lucky in that you have your own Importer / Distributor / American division for these Japanese-built carburettors. We don't have anything of the sort in Europe, let alone the UK where I am based. Maybe they have not got their own website ( I'm happy to be proved wrong on that ) but surely they will have a phone?..... Just for the record - any info. regarding Weber carbs will not be of much use when you try to apply it to the sidedraught Mikunis. PLEASE don't be tempted to start messing around with the Accelerator Pump Stroke ( that threaded rod underneath the body ) as this will be something you find difficult to set up again. A word of warning - all these types of aftermarket "performance" carburettors are precision measuring devices. They all work extremely well if they are given a chance to do so, and if the person setting them up knows what they are doing. If you do not know what you are doing, then leave them to somebody who does. Its worth it in the long run. Alan T.

Sorry to be AWOL while you were scratching your heads on this. I have been out working on a job that took me away from home for a couple of days. First of all, the "Tech." guys at Beaverton Nissan need to go and bone up on their history a little. I think they are getting confused with the "S20" ( the Twin Cam 2 litre six fitted to the 432 and 432-R, as well as the GT-R models of the C10 and C110 Skylines ). The "S20" is a whole engine type, and not just an engine block. The "L20" is an engine block as well as an engine type ( thanks for the confusion - Nissan ) and was fitted to a list of Japanese domestic model types and variants that would drop off the end of this page its so long. Anyway, the L20 block and "Y70" head combination is something of a nail I'm afraid ( sorry ). It was a fairly late incarnation of Low Emissions L-series sixes, and this one probably did not come from an S30 Z originally - its more likely to be a late-ish Skyline engine that has been modded to fit into the Z chassis. You quite often see this kind of "make do and mend" modification on unloved or run-on-a-budget cars in Japan. Depending on what model of Nissan it was originally fitted to, it would or would not need a Sump / Oil Pickup / Dipstick conversion for the Z chassis-fit. More bad news is that this engine is not particularly desirable, and has unusually thin and spindly Con-Rods that are prone to break ( eek! ). Taking the L20 Crank out and installing it in an L24 Block would make a good bore / stroke ratio that would rev to kingdom come if you could make it breathe properly and stop the valves from bouncing. I have seen and heard an L28 block / L20 Crank combination racing in Japan, and it sounded wonderful. Now there's a thought........... Sorry to give you what might seem bad news - but its better if you hear the truth before you start making plans for this engine. And just to nip this one in the bud before it gets set in stone; when talking about the S30-series Z, the L20 was offered on the very first Domestic incarnations of Fairlady Z and Fairlady Z-L. They came with the E30 head first. The Fairlady Z432 and Z432-R ( "PS30" and "PS30-SB" ) were also launched at the same time as the Z and Z-L ( late 1969 ) and were fitted with the S20 Twin Cam 2-litre. This creates lots of confusion outside Japan, as people talk about "Fairladies" as though they were just one model. You have to remember that Japan had a bigger choice of Z than everybody else got. In fact, by October 1971 you could buy six different variants of Z in Japan................ Carchaeology. Fun isn't it? Alan T.

That was the short answer! And I can confirm - no "240Z" ( i.e. "HS30" or "HLS30" ) was ever fitted with an LSD as standard from the factory. They were however available right from the beginning as a Sports Option part. The only S30-series Z to get an LSD as standard was the Z432 ( "PS30" ) and of course its lightweight sister the Z432-R ( "PS30-SB" ) - but they in fact used the beefier R192 diff. which was kind of a superannuated R180. Personally speaking, the No.1 mod that I would perform on any S30-series Z would be to install an LSD ( with a "nice" ratio ) that had a relatively low breakaway setting. It will make the car understeer more, but to counteract this you can throw the car into corners and steer it on the throttle. Its not necessarily the fastest way around a corner, but it is certainly the most entertaining. Too high a breakaway setting makes the car handle like a race car on the street ( and that can be a real pain ). On the limit with no LSD, the nearside driving wheel will spin up and cornering traction is lost. You don't realise how bad this is until you try a Z with an LSD fitted. All those posts about "can a stock Z get rubber in second?" just prove that people have no idea what they are talking about. When you break traction on one wheel it does not count! Its when you break traction with both driving wheels that things start to get entertaining. Money spent on a good quality LSD unit is money well spent indeed........... Alan T.

No.

Aw shucks Ross, you're such a flatterer..... As far as the Carbs to ECGI changeover goes - I can only tell you about the situation with the race cars. The swapover to Injection on the road cars ( and they did not use their own ECGI system ) is a mystery to me as it falls somewhere outside my area of interest - sorry. I tend to wear blinkers and only take notice of things that interest me ( selfish, isn't it? ). Mind you, I bet you any money that Nissan once again had no clearly defined switchover point from Carbs to Injection on the Z. They probably tried it in certain markets first and then gradually blended it in. I know that carburetted versions were being sold alongside Injected versions at one point in Japan, and this was possible because Japan always had several different models of Z to choose from on the Home market. Just about everybody else outside Japan got one particular model / spec. for their particular market. On the race cars, Nissan were also using the ECGI Injection on cars contemporaneously with Carburetted versions. They started out injecting their Sports racers ( like the evolutions of the R380 series and up; for example the GR12 was a bloody fantastic engine - big inch V12 with double overhead cams and whacking great injection trumpets ) and then they were injecting the S20 sixes in the GT-R before the Z even came out. Even "lowly" Sunnies got injected in race trim. The Z432-R racers sometimes got the ECGI and the 240ZR was used with both too. In most cases, the Injected cars went to the "Ace" drivers or were used on the cars where the most power was required. The Works Rally cars used them both on the "normal" L-series sixes as well as the LY "Crossflow" engines, with the first instances of injection being used in around late 1971. The Circuit racers had them a bit earlier. Sorry I can't help with the date for the introduction of Injection on the Aus market road cars. All the best, Alan T.

What's up dohc? The factory used the Mikunis on all their race cars unless otherwise fitted with the ECGI Fuel Injection. My interest only goes up to around 1975 ( or even 1976 with a little pinch of salt ) and then picks up again about 1989 / 1990 when I saw the Group A R32 Skylines racing in Japan ( wow....... ) - so I can't vouch for the gap in between, and it hardly matters anyway. There were a few honourable exceptions to the dross of the post "Oil Shock" period - notably the "Silhouette" series race cars, which were mad - but they were all injected anyway. Prince used some race engines that they married up with Weber carburettors - notably the GR8, and some of these survived the transition between the last days of Prince proper and when they were taken over by Nissan. The Prince Skyline S54 GT-B was fitted with 40DCOE Webers from the factory ( and was the precursor to the C10 series GT-R ). A few semi-Works / privateer teams used Webers on their Skyline and Z race cars - but the proper Works cars always had Mikunis. Like me, they probably thought the Dell'ortos were too ugly to love............... If ANY sidedraught carbs don't work right its probably the owner / fitter's fault. If they go out of tune ( after having been IN tune ) then its probably down to having a crap linkage. These things don't change their settings on their own. Happy twiddling, Alan T.