Valve cover differences

[hls30.com]

Well, we know what the next piece of "Club Merchandise" should be!

Will

[Gav240z]

for what it's worth this is my "NISSAN" valve cover from my L28 with a P90 head. As far as I know the engine was not imported but cannot be sure. I've seen this valve cover before but with a slightly BIGGER "NISSAN" stamped onto it.

http://www.classiczcars.com/photopost/data/500/1316digitalcamera_046.jpg sorry it's upside down can't take photos of it at the moment it's at the engine head shop.

I have enjoyed reading this thread for the most part.

[Carl Beck]

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?

Alan T.

Hello Alan:

Actually I have now written about five answers...just haven't posted them. A couple of them just made me feel better after writing them, but they were ah... too... bluntly honest .. to send. Most would have seen them as "mean";-)

A couple of them were as honest, as I could be and still not be outright flames... but then I thought the chances of getting you to settle down and hold an actual "discussion" were pretty low, you seem to so enjoy provocative debate and wining the debate becomes way to important to you. Then that turns into Posts and Replies that get way to complex and way to long.. and our fellow forum members grown in pain..

The truth is Alan, there are many subject area's I'd love to "discuss" with you. But you simply must quit assigning evil intent to my statements, quite calling me a lair and understand that I really attempt to mislead no one.

The ZCCA Historian, Dan Banks and I have spent hundreds of hours collecting source materials and doing extensive research on most subjects we write on. Where necessary or appropriate we reference them so others can read them for themselves. (I mention Dan because he has been a huge source of information related to the history of Nissan Motors as well as the Z Car).

I will say up front that I do not believe that just because a magazine article or book is written in Japanese, or written by a Japanese writer - it somehow is to be given more credence than anything written English. I think we both have enough experience in that regard to know how badly mangled an interview or writing can get before it gets to print. I know that you and I can read the same article and come away with completely different perspectives of what was written.

Secondly, since neither I not the vast majority of our fellow forum members can read the Japanese sources you site as references - to decide for themselves the true quality, content and meaning of the wittings in total.. I can't really respond to your interpretation or possible misinterpretation of them. if you read your source materials like you read my Posts... well....

All that said - I'll try one more time... next Post....

kind regards,

Carl B.

[Carl Beck]

....snipped...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.

.....snipped...

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.

Hello Alan:

I don't believe I disputed that the old L20 may have been an "ancestor", just that it wasn't the parent.

You and I, as usual, simply have a different perspective on this. In this case, I believe you are saying / insisting that the Nissan L20, as pictured by you circa 65/66, simply evolved into the L20A, you feel that they are one and the same and purely a Nissan design. You also seem to believe that the more modern L16, did not precede the more modern and differently named L20A in both development and production, or rather that since you believe that the L20/L20A are one and the same, then the L16 and L24 are simply detail changes to the 63/68 L20.

I on the other hand see evolution as a distinct series of small incremental changes, leading from the origin to the current example. I see no such incremental progression between the L20 and L20A. Rather I see a completely different engine, unlike any that Nissan had ever produced before - pop up out of nowhere - with the appearance of the L16 in late 67 as specified for the PL510 in 1966.

I do see clear incremental evolution from the L16 to the L13 (same block de-stroked & head) and then to the L24 (same block/head with two additional cylinders) and L20A (same block design / head design cast in a smaller bore, and in some cases with small main bearing supports) all sharing a visibly common design, quite different from the Mercedes looking L20 of 65.

If your perspective is that the old Nissan L20 is the new L20A, with "minor detail" changes... then your time frames must be correct, and the new L20A engine was around for five or six years before the Z.

If my perspective that the L16 was a clean slate design, with collaboration between Nissan and former Prince engineers is correct.. Then a completely new block was designed and cast, a completely new cylinder head with associated combustion chambers were designed and cast, a completely new valve train was designed etc etc - then the L24 was indeed evolved from the L16. In this case I do clearly see the small incremental changes that represent the evolution of a design. That new design however starts with the L16.

How much change has to take place in one step - before the evolution of an old design is completely replaced with a new stating point? We simply differ on the answer to that question.

Just as many view the evolutionary path from the Fairlady roadsters, to the Silvia, then to the Goertz Nissan 2000/Yamaha A550X and ending at the Z Car; I suppose they would view your perspective as correct. I however belive that the L16 was as completely revolutionary within Nissan Motors, as the Z Car was itself. About the only thing the Z and the L16 have in common with the Fairlady Roadsters and the old M/B style L20 - is the name of the company that produced them all.

If you tell me that the engineer that designed Nissan's original L20 circa 63 (did you say), is the same person that designed L20A... then I would tell you that the metamorphosis (caterpillar to butterfly) in the design took place in his mind, but not in the physical world. I would hold that it was indeed a second clean slate design, not a further evolution of the first and that the L16 preceded the L24/L20A. The L13/16 and/or the L20A/24 could very well represent the evolution of the knowledge and experience the Design Engineer possessed.

It may be all perspective and perception, but I believe that to understand where the Datsun 240-Z came from, and why it became so hugely successful - one has to look at the difference between evolution and revolution.

I believe that it was revolution, and that was driven by Mr. K in America, Nissan Motors need to increase production by increasing Export Sales, the merger with Prince Motors and the restructuring of the in-house design department - all of which converged at Nissan in the 65/66 time frame and resulted in the creation of something totally new for Nissan. The first outcome of that revolution in Design and Engineering related to new engines was the U20, followed by the L16 in the PL510, and then the L24/L20A.

As I said, I know we see things quite differently - I would sincerely encourage you to simply tell the story from your perspective of the subject, and I'll hope we can conduct a reasonable discussion.

regards,

Carl B.

BTW - If anyone following this thread doesn't already have a copy of Brian Longs translation from the original Japanese, of "HOW I DEVELOPED DATSUN 240-Z STYLING", written by Mr. Matsuo... just send me an e-mail at beck@becksystems.com and I'll loan you my copy. (in MS-Word format).

[HS30-H]

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.

The ZCCA Historian, Dan Banks and I have spent hundreds of hours collecting source materials and doing extensive research on most subjects we write on. Where necessary or appropriate we reference them so others can read them for themselves. (I mention Dan because he has been a huge source of information related to the history of Nissan Motors as well as the Z Car).

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?

I will say up front that I do not believe that just because a magazine article or book is written in Japanese, or written by a Japanese writer - it somehow is to be given more credence than anything written English.

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.

[HS30-H]

I don't believe I disputed that the old L20 may have been an "ancestor", just that it wasn't the parent.

As far as I could tell, you were spending time trying to make a direct link to Prince. Viz:

.....Actually the Prince G7 of 1961 looks amazingly like the Nissan L20 of 1966.

.....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.

You and I, as usual, simply have a different perspective on this. In this case, I believe you are saying / insisting that the Nissan L20, as pictured by you circa 65/66, simply evolved into the L20A, you feel that they are one and the same and purely a Nissan design. You also seem to believe that the more modern L16, did not precede the more modern and differently named L20A in both development and production, or rather that since you believe that the L20/L20A are one and the same, then the L16 and L24 are simply detail changes to the 63/68 L20.

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.

......I see no such incremental progression between the L20 and L20A. Rather I see a completely different engine, unlike any that Nissan had ever produced before - pop up out of nowhere - with the appearance of the L16 in late 67 as specified for the PL510 in 1966.

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......

I do see clear incremental evolution from the L16 to the L13 (same block de-stroked & head)............

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 then to the L24 (same block/head with two additional cylinders) and L20A (same block design / head design cast in a smaller bore, and in some cases with small main bearing supports) all sharing a visibly common design, quite different from the Mercedes looking L20 of 65.

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.

If my perspective that the L16 was a clean slate design, with collaboration between Nissan and former Prince engineers is correct..

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'.

I however belive that the L16 was as completely revolutionary within Nissan Motors, as the Z Car was itself.

L16 on its own again. A reminder of your perspective.

......I believe that to understand where the Datsun 240-Z came from, and why it became so hugely successful - one has to look at the difference between evolution and revolution.

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.

BTW - If anyone following this thread doesn't already have a copy of Brian Longs translation from the original Japanese, of "HOW I DEVELOPED DATSUN 240-Z STYLING", written by Mr. Matsuo... just send me an e-mail at beck@becksystems.com and I'll loan you my copy. (in MS-Word format).

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?

[NZeder]

I am with Alan on this one. Here in NZ we have a lot of JDM imports so we have S30,S31, skylines, etc plus we had a Prince assemble plant back in the day so we have some NZ new Prince Gloria's, then Skyline GTB both badged as Prince and later the new owner Nissan. There are few of the Super Six here also. And having seen under a few of the engine bays you can't ignore that these engines were the step stone to the L20a/L24/L16 = L series line of engines. I think you are kidding your self if you thing the L16 was a clean sheet of paper and the that 6 cylinder was not designed at the same time - remember that Nissan had the 2+2 shape almost sorted before the 2 seater that was released in the Export Markets as the 240z yet we did not see this for another 4 years. So I could be said that Nissan did the same with the L6 - designed and complete at the same time as the first L4 were released.

Also if you think the L16 was a clean sheet then you must also have to think that the Z20/Z22/Z24 were a clean sheet (so therefore the L20B) as these differ from the original L4 in height and cross flow (except the L20B) but these engines were an evolution from the earlier L13/L14/L16/L18 designs. So with this in mind and looking at the picture Alan has provided you can clearly see the same principles in work when looking at this early L20 and comparing this to the L20a/L24/L26/L28's that were to follow. If you have seen any of these early engine in the flesh you know what I am talking about.

We also have a number of different market cars that have been imported over the years (talking just the S30 series now but this does include other models/makes) we have Fairlady Z (S30 both L and S version), Fairlady Z (S31 both L and S version), Australian spec 240z/260z, JDM Fairlady 240z (aka the ZG), UK/Europe spec 240z/260z, US spec LHD 240z/260z and 280z. The list goes on. So here I think of the S30 as the family not just the 240z that was released to the US in 69. If you think like that then you fall under the "US we are the world mentality" which is just wrong.

[sakijo]

here's an interesting valve cover up on Yahoo Japan.

http://page7.auctions.yahoo.co.jp/jp/auction/g43294271

[sblake01]

Looks like someone modified that one.

[olie05]

Looks like somone glued on a "datsun" logo over the nissan part of nissan ohc.

[montoya_fan01]

Looks like somone glued on a "datsun" logo over the nissan part of nissan ohc.

and painted/powdercoated it "Pimp My Ride Red"

[NZeder]

I see someone mentioned the L4 rocker cover that had "Datsun OHC" on it - I have seen these here in NZ, I think I might have one. I know that I have one that has "Datsun 1600 OHC" next time I visit the garage were this is stored I will take a pic and post it here.

I do see clear incremental evolution from the L16 to the L13 (same block de-stroked & head) and then to the L24 (same block/head with two additional cylinders) and L20A (same block design / head design cast in a smaller bore, and in some cases with small main bearing supports) all sharing a visibly common design, quite different from the Mercedes looking L20 of 65.

Re the comment on the L20A with the small main bearing supports - I know that from 79 onwards the L20aE (ie EFI) used the smaller big end journals and rods much like the L24E you got in the USA for the Maxima - again Nissan using the same rods in the L20a and L24 like they did in the earlier engines, difference stroke and bore. These smaller journaled cranks/rods are common as mud here in NZ, these can be found in a number of JDM imports with the L20E and the L20ET (to be correct that should read L20aE and L20aET).

Alan/Carl others can anyone shed some light on the Mercedes comment - I know it has been discussed before but I have been told that Nissan paid Mercedes a license fee much like Mikuni did when it licensed its carb technology from Solex (they then evolved the product to a number of different carbs designs - I guess much like Engine builders do aka the Nissan A Series engine was a licensed copy of the Austin OHV engine that was improved on by Nissan)

Has anyone else heard that an RB torque plate can be bolted onto a L6 block? I have been told that if your engine builder does not have a torque plate for your L6 boring then ask them if they an RB unit as it will work also :surprised