HS30-H

As far as I could tell, you were spending time trying to make a direct link to Prince. Viz: .....and that's how you set out your stall. "1966" comes out of nowhere, and the Prince G7 is implied to have a direct engineering link with the L16 ( and therefore the L24 ). It does not. Carl, my "perspective" comes from reading the words of Mr Hiroshi Iida - the chief designer / engineer of Nissan's 'L-Gata' engine. I didn't have any kind of 'immaculate conception' and make anything up on my own. This is not my truth - it is the truth of the man that was responsible for the engine's creation. You seem to be setting great store by the difference between the 'L20' and the 'L20A' - almost to the extent of avoiding the idea that they are directly related. This is of course not historically accurate, and the L20A is recognised in Japan as an update to the basic L20 ( first ) design of "L-Gata Module" ( more on that later - maybe in its own thread ). You draw a line between the two, and it would appear that ( from other things you have written ) the main purpose of this is to delineate between the L24 and anything that might threaten its reputation as 'the' Z engine. That would appear to be why you wanted to deny that the L20 was slated for the S30-series Z before the L24 ( misinterpreting Matsuo ). You are it seems always in denial that the S30-series Z was a family of cars from the drawing board. The fact that the engineers at Nissan - headed by Hiroshi Iida on the 'L-Gata Module" - were also aware that they were designing a family of engines seems fitting answer to you. With all due respect to you Carl, this is complete bullsh*t - and I wonder if you would be bold enough to stand in front of Hiroshi Iida and say such a thing. I'm not speaking for him - but I have to wonder whether he would believe you knew anything about the 'L-Gata Module' and the design brief that he and his team had been given in November 1964. Since he and his team designed the L20, the L20A and the L13 / L14 / L16 - I'd have to wonder what he would say to you...... There you are - doing it again. The L13 was designed at the same time as the L16! WHY are you implying that the L16 came before the L13? The only reason I can think of ( stop me if you've heard this one before ) is because it fits in more snugly with your preconception that the Export market was leading all design and engineering at that time. It was not. And here once again. You seem to pay no heed to the fact that the 'L-Gata Module' was purposely given a bore spacing that would accommodate a large percentage of increase in piston diameter, and a deep enough block casting to accommodate a wide range of strokes. THIS is the whole point about the evolutionary link between the first production L-Gata engine and all the others that followed. And HOW can you state that the 1965 L20 ( as used on the H130 ) was so radically different in design and layout to the L13/L16/L20A/L24???!!! And especially to re-state that old 'Mercedes' chestnut - its a joke! Anybody who looks at that H130 L20 will see its obvious similarities to the L20A and L24 and indeed all the other L-series engines. In fact, the only significant visual difference would be the movement of the thermostat housing. Don't cite the cam cover attachment difference, as the first L20As also had this type. Sorry - but I don't know where you are coming from. But it is clear - you are NOT correct. In no way can the L16 ( there you go - citing the L16 as though it is of prime significance again ) be called a "clean slate" design. The 'L-Gata Module' was designed before Prince engineers were on the scene at Nissan, and the L16 is simply one of a family of engines that evolved from that 'Module'. L16 on its own again. A reminder of your perspective. And I believe that to understand where the '240Z' came from - and why so much of its design turned out like it did - one has to look at the WHOLE story. That includes thinking of the S30-series Z as a family of models from the drawing board, right through the engineering and production process and on to the showroom floor. Ignore ANY one of those models ( or more - as you are known to do in the case of the Fairlady Z and Fairlady Z-L ) and you will blind yourself to the whole story. This is the same mistake as ignoring Hiroshi Iida's 'L-Gata Module' and focussing primarily on the L16 as some kind of 'Year Zero' marker. Big mistake. And anybody who receives the translation might like to note that my translation of the original chapter title - written by Matsuo san - ( "Shodai Z Design Kaihatsu Shuki" ) would read: "Original Z Design Development Essay" - which might give you a little inkling about 'perspective'..........Matsuo san was writing about the whole Z family - as seen at the 1969 Tokyo Auto Show - and not just the 'Datsun 240-Z'. Alan T. PS - By way of a reminder, here's that photo of the L20 engine - as used in the H130-model Nissan 'Cedric Special Six' in 1965. Does anybody seriously think that this does not have a direct evolutionary link to 'our' L20A, L24, L26 and L28 engines?

Carl, Thanks for finally responding ( look what it took to get you to the table again ), and thanks for the free character assessment. I'll add it to my collection. Puzzlingly ( considering the subject is a Japanese car ) I don't see much in the way of Japanese sources in your bibliographies, either at zhome.com or here on classiczcars.com when you mention your 'sources'. Granted the language problem is a bit of a hindrance, but it appears to me ( with my "warped agenda" ) that you positively avoid Japanese data unless it backs up what you already believe. My personal experience is that I learned far more about the subject from Japanese sources than I did from English language sources, with one of the most important lessons being a sense of perspective on a Japanese industrial product. Wouldn't you expect a scholar of ancient Greece to learn a little about what was written in the ancient Greek language? Perhaps an extreme example - but do you take my point? I think this is not exactly rocket science, but it may be anathema to somebody who keeps calling the S30-series Z an "American Car, Made In Japan" ( that's a high-mileage quote these days, and I've put some miles on it myself ) and somebody who appears to pay more attention to sales jingles and advertising copy than the voices of the blue collar guys. Dan Banks - as far as I can tell through my contact with him - seems to me to be far more open-minded about the Japanese side of the story than you are, and perhaps a little more pragmatic. He certainly seems to respect Japanese source material, and I don't see that with you. But what do I know? Maybe so ( and by the same token, just because it is written in English doesn't mean it is automatically correct ), but have you actually seen the articles / books that I have referenced in this thread? You appear to be damning or discounting them without even having knowledge of what they contain. In the case of the interview with Mr Hiroshi Iida ( the chief design engineer of the Nissan L-Series engine ) that would appear to be folly in the extreme. Where else are you expecting to see an interview with the man? If you want to know what is written in the piece ( which seems a good place to start if you want to give it "credence", or to discredit it ) then you will have to have it translated for you.

Carl, I asked for your response to some questions I put to you. You seem to be ignoring this request so far. Do I take it that you have no answer? This topic is close to my heart. I think the Nissan 'L-Gata' engine was a great basic engine design that is pretty much World-renowned for its flexibility, reliability and durability - let alone the fact that it was able to be turned into a race winner. But ( just like the situation with the design of the S30-series Z ) almost nobody knows the name of the key designer behind it, and its true heritage and evolution is distorted by rogue data and advertising copy. I think this is a great shame. I'm going to embark on starting a new thread topic in the near future, as I think this subject warrants it. But I also think that the points raised in this thread need to be settled before it goes into the archives and gets used as reference material in the future. So Carl - I'm asking you politely - I think it requires further comment from you. In my opinion, that's what these forums are for. Alan T.

Yes, its to make more space for those "BIG" cams that we sometimes hear people talking about........ 26th-Z probably touched on the closest reason to the truth. Curves cost more money. Straighter lines are cheaper.

Some comparison pics:

A few more:

Hi Ron ( and Jim ), I have a little info on the man and the company. Maybe you would like some photocopies of what I have. I can post them to you by Air Mail. Let me know. As for the particular head in question - data on that will be one of those 'how long is a piece of string' type questions. I should imagine there are certain details that conform to the Kakimoto Racing 'menu', but you'd also have to imagine that a certain amount of 'bespoke' work might be possible. You should at least be able to measure what you have got ( valve sizes, cam specs, combustion chamber cc etc ) and get an idea of what it was built for. The 50mm Mikunis are a clue that it was most likely built for a 3.1 conversion ( Kakimoto's stock in trade back in the late Seventies and early Eighties) using an LD28 crank, L14 rods and Honda XL500 motorcycle pistons. High probability that it was a 'street drag' engine, too. Kakimoto built his reputation in Japanese 0-400m competitions. Some pics:

Hi olie, Mine is at least 15 years old now, and I can't remember which company it was that had my version cast. I think I remember buying it from 'Escort', but I don't believe it was 'their' version. The 'original' casting pattern was paid for by Kakimoto Racing I believe, and the others are all taken from modified versions of that pattern - cast at the same foundry. Probably a case of the foundry keeping some ownership rights to the pattern and making their money back by letting other companies have their own versions that didn't infringe whatever rights Kakimoto still held. That's just an educated guess though. Kameari Engine Works in Yashio City, Saitama prefecture still sell the 'DATSUN 2400' version with 'OHC' on the front. Price is 50,400 JPY including sales tax. I know the company well and have been dealing with them for many years now. I haven't seen the 'DATSUN 3100' version on sale for some years now, and I presume they are fairly rare. This is probably due to the fact that they were cast in batches, and not enough demand for a new batch has held back production. Bound to show up on Yahoo auctions Japan eventually if you keep your eyes open........ Sorry I can't be of more help. Alan T.

Come on Carl, play the game. I'd like to hear your justification for standing by some of the erroneous 'history' you have added to this thread - especially in light of my challenges to it, when I cited the words of the very man who designed the Nissan 'L-Gata' engine. That's not my take on it all - I'm just the messenger. The history comes from the mouth of one of the main protagonists. It completely contradicts your version of events. Here are two of the quotes that warrant further scrutiny and discussion: Both of these are clearly wrong according to historical evidence and the words of the designer of Nissan's 'L-Gata' engine. What's your reply to that? I think I need to start a new thread on the topic of the true evolutionary development of the Nissan 'L-Gata' / 'L-type' / 'L-series' engine. Alan T.

Sure I have. Why not? Its no 'concours' queen ( dread the thought ). That thing's had R.S.Watanabe 8-spokes and a Sanyo Sports Kit triple carb setup since time immemorial ( well, long before it came to the UK anyway......). Its got plenty of factory Sports Option parts on it too though. 'Datsun'? What's wrong with that!? Actually, you probably know that many Japanese have a strong affection for the Datsun brand name ( just look at Kats for example ) and the name still gets used with a certain recherche du temps perdu. I often grin when I read people talking about their "Datsun" engine, when in fact it says 'NISSAN' in big letters along the cam cover. You could see my cam cover as Ying to that Yang; A Japanese company using the 'Datsun' name on a Nissan engine out of a kind of inverted snobbery. By the way - its not on the car anymore. Its sitting on a shelf in my garage. The organ transplant was rejected, so to speak. Alan T.

Two shots from the 1969 Tokyo Auto Show. 'Cedric Special Six' engine bay and 'Fairlady Z-L' engine bay. Both 'NISSAN 2000 OHC' cam cover:

Carl, There was no KGC10 in 1968. Here's a scan from the 1968 Skyline 2000GT ( GC10 ) sales catalogue:

You've never seen one of those before? Aftermarket, based on one of the 'Kakimoto Racing' originals. There's one sitting on top of my engine:

Wow Carl, it seems just like old times. You are spouting backward, revisionist - almost 'Creationist' - untruths and plain lies about Nissan history again. You're too late. The Nissan 'L-gata' engine had already been designed, tested, productionised and fitted in cars before Prince was merged with Nissan in 65/66. I'll just repeat a quote from you for emphasis: Why did you choose 1966 Carl? Does that year's L20 have any special significance over and above the L20 of 1964 or 1965? Surely you are not saying that the L20 didn't exist before 1966?....... You're still looking down the wrong end of that telescope, Carl....... Oh dear, I can see where that is leading you: There it is. Total nonsense backed up with unrelated and irrelevant data. I find it distressing to think that people will read what you have written and treat it as historical fact, just because it comes from the keyboard of a known and trusted 'scholar' on the subject of the Z. They are being misled. Carl, the beginning of the Nissan 'L-Gata' engine came more than three years before that. Why are you perpetuating the myth that the L16 'begat' the L24 - when BOTH of them are simply evolutions of the L20 six that was already on the test bed in 1964, and in a production vehicle by 1965? Complete bullsh*t. This is the distortion of historical facts simply to suit the 'truth' as offered by Nissan Motor Co. USA's advertising copy - which you seem to have fallen hook, line and sinker for more than 35 years ago. How can you say that they were "unrelated"??!! This is complete nonsense. Its just laughable. Just how you seem to think you can draw an arbitrary line of demarcation across a clear timeline of evolutionary development - for the sole purpose of supporting a lie - is shocking and shameful. I thought you had learned some fresh history about the true evolution of the Nissan 'L-Gata' engine on this forum over the last few years, but it seems not. Now you are simply distorting the truth to make it fit other lies. And it goes on: Yes - indeed why? Would it perhaps be related to the fact that you obviously know next to nothing about the origin, design and production history of the Nissan 'L-Gata' engine? Would it possibly be related to the fact that your version of 'Z history' on zhome.com for some inexplicable reason completely ignores the Japanese home-market L20-engined cars? Is that a clue? Only you know the answer. I remember you telling me that you thought the Japanese L20-engined cars were "irrelevant" to the history of the '240Z'. A clear demonstration of the way you approach the history of the S30-series Z. Quite bizarre. You obviously misunderstand the situation here too. Matsuo was indeed worried about going above the 2 litre taxation class in the Japanese market ( and it wasn't just Matsuo of course....). However, what you don't seem to have grasped is that the S30-series Z was slated to have both the L20 and the L24 for the Japanese market at that point - with the L24 also being used for 'Export' versions and a Japanese home market 'peformance' model ( in fact, the decision to use the L20 engine in the Z predated the existence of the L24 engine ). This was quashed by higher management who wanted to make the 'performance' home market model use the S20 twin cam - which would give them a prestige high performance model that stayed within the 2 litre taxation class. How you can imagine that the L20-engined Z didn't come into being until after the L24-engine had been specified for the Z just demonstrates that you always have the cart before the horse. I can't help thinking that this is further evidence of your desire to 'prove' that the HLS30U was some kind of Z genesis, and that you are prepared to distort the facts in order to 'prove' it. Duh....... If you took the time to research it properly ( and that means from Japanese sources, you would see that the L20A was already powering many of the cars that were sitting in the car park at Nissan's Japanese press-preview event for the S30-series Z in October 1969! At that point, it had been around for the best part of five years.......... Some recommended reading for people who are interested in the true history of the Nissan 'L-Gata' engine. Unfortunately, it is written in Japanese - but that should not be a surprise, surely?: *'Ten Years Of Japanese Engine History' - by Eizo Ikeda. Published in the February 1972 issue of 'Motor Fan' magazine ( Japan ). *'Secrets Of The Nissan 'L-Gata' Engine' - Published by Sankaido Motor Books ( Japan ) 2005. *'Interview With Mr Hiroshi Iida - Designer Of The L20-type engine' - written by Manabu Kumano. Published in issue no.102 of 'Nostalgic Hero' magazine ( Japan ) - April 2004. I'll just finish off by posting this picture, which depicts the L20 six as fitted to the 1965 H130 'Cedric Special Six'. THIS engine was the true evolutionary ancestor of 'our' Nissan L-series engines: Alan T.

Not the S30 / S31-series Fairlady Z either. First Z to be turbo-equipped from the Factory was the S130-series. Its a UK license plate, and the 'T' suffix indicates that the car was registered between 1st August 1978 and 31st July 1979. Seeing as it is RHD, there seems very little likelihood that it is a '280Z' - as the '280Z' was only made in LHD. The UK market got the 'RLS30' and 'GRLS30' '260Z' models until the S130 '280ZX' was phased in - so the car in question is more than likely a very late UK-market '260Z' model. I don't know where the spoiler came from, sorry. Alan T.

Nostalgic Hero has never done it for race cars to my knowledge, but they have had popularity polls for standard car models. I think Montoya_fan01 was right; this kind of thing is far too subjective for everybody to come to any kind of democratic decision - but it would be nice if the activities of Japanese cars in their homeland were to be taken into account ( and that goes for the British magazines too......... ).

Hi Mike, OK - thanks for the clarification. My mistake. I thought you were falling into the trap of thinking that all L20As were the same. Regarding compression ratios; The earliest Fairlady Z and Z-L models had 9.5:1 and 8.6:1 as the 'high' and 'low', but they later switched to 9.0:1 and 8.5:1 - and I think the car in question falls into this bracket judging by its age. The better translation would probably be "higher" and "lower" compression, and it was sometimes expressed in fuel grades ( 'high octane' version and 'low octane' version ). Alan T.

Mike, Like I said before, beware what you see in the English-language manuals relating to L20As. Not all L20As were created equal. The Fairlady Z version is different to the others..... John, I want to urge you to not give up on sourcing a set of replacement pistons for the L20A. Just because you can't find them on the 'Net doesn't mean that they aren't available. You will need to get them from Japan, and for that you will need a kindly contact there who will source them for you. I think this is your best course of action. The 'Net is NOT the cure for all ills or the answer to all questions - especially for the owner of a Fairlady Z. Even if you did use the L24 pistons ( your risk to overbore by that much ) you'd still have the small valves, small ports and small manifold passages of the L20A, as well as the 'small' Hitachi HJG38W carburettors. Food for thought?

And whilst we are on the subject of WEC / Group C: I would have thought that Hasemi / Hoshino / Suzuki's victory in the 1992 Rolex 24 Hours of Daytona in the Nissan R91CP was worthy of a place in that 'Top 10' list above some of the other listings?

Yes. But Nissan called that first ( longer, lower, wider ) DR30 lookey-likey a 'Skyline Group C' and entered it in Group C races. The second car ( shorter, higher, narrower ) was a true 'Super Silhouette' class car, entered in Super Silhouette series races. Two different cars. Not guilty! I never said there was. Nissan made the race entries - not me. Look at the captions on the pictures. I wouldn't have mentioned the March Group C cars - but Eric associated the Tomica model with the Super Silhouette Skyline. I'm trying to differentiate between them and clarify the distinctions - not the reverse. Let's not get mixed up here. What we have is a Super Silhouette car based on the vestiges of a factory DR30 bodyshell, a Group C March 'Skyline Turbo C' with a non-Skyline Nissan engine, and something in between the two: the "Group C Skyline Turbo". Exactly. There was nothing 'Skyline' about it. Neither was there anything Silvia about the 'Silvia Turbo C' or anything Fairlady about the 'Fairlady Z-C LM03'. All were out-and-out Group C cars with the names of current Nissan models attached to them. It was just product association. Kind of like most major manufacturers did - and still do. Cite Ford with the Ford GT cribbing the Lola GT back in the Sixties, or Aston Martin ( AKA Ford ) asking Prodrive to design, build and run their DBR9 race car in 2005.

Arne, Bear in mind that the English-language factory engine manuals that covered the L20A and L24 ( green cover ) usually only listed specs pertinent to the sedan, van and pickup versions of the L20A. These were almost exclusively single carb and low compression versions of the L20A. John's car will more than likely be the high ( 9:1 ) compression version - but it is worth checking and making sure. John, Here's a scan of a page from a Nissan factory parts manual for your reference. A good Nissan dealer in the USA ought to be able to follow up on these numbers and find the superseding numbers ( where applicable ). Watch out for 'high' and 'low' compression pistons ( I marked them accordingly ) - but I'd go for 'high' anyway, although be careful that you have a matching distributor. Seeing as the car has been in the family from day 1, my personal bias would be toward keeping the engine close to original wherever possible. If you want more pep you can always put a different ( bigger ) engine in there and keep the L20A on ice. You could pick up a good used complete L24 / L26 / L28 and match it up with your transmission for not much money surely? Please tell us more about the car. Got any interesting stories / documents / photos? Was it a 'G.I. Bride'? Alan T.

Hi Eric, Yes - the longer, lower, wider car was the earlier of the two. As I mentioned above, either the rules changed - or somebody protested - and the earlier car was no longer legal. They built the shorter, slightly higher and slightly less wide car to replace it. I don't believe that it survived. I would have thought it would have surfaced by now if it had. It probably got recycled and many of the parts used on the one that we often see today. However, who knows what's lurking in a shipping container tucked behind a storage warehouse somewhere? Some interesting cars are still surfacing over there...... Well, I think we might think of the first Super Silhouette car ( the longer, lower, wider one ) as a kind of fork in the road. It was racing against 'proper' Group C machines that had mid-engine layout and tubbed chassis - whilst the Skyline was still front-engined and with a spaceframe chassis. It didn't really stand much of a chance against that kind of competition. So you can see what they did: The next Super Silhouette series Skyline ( along with the Bluebird and Silvia versions ) was built around a genuine factory body shape - these rules being more strictly enforced - whilst Nissan went mid-engine and tubbed chassis for their 'proper' Group C machine. Here's a pic of the 'Skyline Turbo C' Group C car ( actually a March 85G ) from the 1985 Suzuka 1000km race:

Lachlan, I believe they did indeed win a few races, but came fourth overall in the 1968 championship. One of the cars that Toyota sent to Shelby was their record-breaking car. I notice the "Top 10" list doesn't include any of the high speed and endurance record-breaking activities of Toyota, Nissan and Prince - even though they were World records for their class. It probably needs to be a 'Top 50' to do the subject justice I'd have thought.

Hi Victor, Yes - as far as the data I have is concerned - the 'Group C' version of the Skyline Super Silhouette ( the longer, lower, wider version than the one that still exists ) also used the big single-turbo version of the LZ20. They claimed 570ps output. There was a weird N/A 'FJ23' hybrid engine that was used in the first of the rear-engined Nissan Group C machines, and I was once told that this engine was tested in the earlier Super Silhouette car - but I don't see any written evidence of this. I believe the longer, lower, wider version either got banned or withdrawn because it was judged to be outside the regulations of the series. I think it was to do with keeping the dimensions of the original base model, and particularly in the cabin area - but again I don't know too much about the ins-and-outs of it all. I suspect the lack of documentary evidence might point to a bit of 'brush it under the carpet' type activity.......

Here are some pics of the car I was talking about. Note that this is not the same car as the one in Eric's pictures; it was longer, lower and wider. Apologies for the picture quality ( especially page breaks ) but photos of this car are not all that easy to find........