Engine differences about Series 1 S30 Zs?

[Z fan]

^^^

[Kerrigan]

Yes. That's it. A plain 1971 FairladyZ-L with the stock L20 engine.

You're correct ZH.

I'm happy with that because, as you said, it fits my cognitive bias, which comes from looking at mine in the metal flesh.

I believe it's the original engine to the car; the mounting fixtures and bolts and transmission bolts have not been removed. At least it wasn't swapped by the original owner nor me as the second owner.

I have seen, in a posting, a picture of an 6-cylinder engine block stamped L20 followed by a number with an A prefix on the second number pad. I don't remember the serial number but it looked like

L20 A12345

So I guess that's what has caused the confusion, as I understood it to be an L20A engine.

Can't believe pictures in books. The photo of the cockpit of a early FairladyZ-L (in Brian's Z book) shows a horn button without an image of a horn at the bottom. Mine doesn't have one either, but people insist it isn't correct. I'll go with the Nissan photograph. The one without the horn image is correct, but perhaps only in this year? Who knows. Not I for sure.

One never learns anything unless one asks a question of more than one source (or Forum). I've changed my bias on a lot of things on this car that I though I had right, but others showed me where the information was incorrect.

No fuss. Just Yankee curiosity.

And again, thank you for being "nice".

I didn't read through all of your other posts but I do see that you might having some "cognitive bias" going on. You're interpreting things to fit what you "know" instead of changing what you know to fit the reality. There's nothing written anywhere that I see about an "A" stamp. Why would you need an A or a B stamped on the engine, all you have to do is count cylinders. So looking for an A stamp seems pointless. The A and B seem to be for documentation and manual purposes.

The number on the engine would match the number on the body plate, in the USA market. I don't know if they did that in Japan. Is that where the "mis-matched number" thing comes from? It could just be a replacement motor.

From your post farther above it seems like you just have a plain old JDM Fairlady Z with an L20 six cylinder. What's the big deal? The FSM shows it as a stock engine for the car. What are you really looking for?

Edit - seriously, I'm just wondering what the fuss is about.

[Zed Head]

You're good at writing on the margins. I can't tell if you're serious or not.

Anyway, an interesting thread for you might be titled "Who has an L20 engine and what is the serial number, and year of car?" You might get a sampling of information that tells something. The picture from the past that you remember would be a start.

I take it this is an argument about originality, and maybe value, of your 1971 car? Those arguments are served well by comparison with like articles. There must be others out there.

There would be no good reason to mark your engine before the L20B 4 cylinder was planned for production. And, logically, you know it's not an L20B, and it is an L20, therefore it can only be an L20"A". Unless you're trying to find out when Nissan started marking A's and B' on their L20's, if they did. That would be a question that could be answered. Maybe go could out and find out what the 4 cylinder L20B's have stamped on the block.

[Zed Head]

Post #4 - Orange, and only a little rust: `76 710 - Project Datto - Ratsun Forums

Implies that the format is L20X XXXXXXXXX, not L20 X XXXXXX

I would assume that the format would be the same and would only be used when the potential for confusion was realized.

[Zed Head]

Here's one from this site that would be good to compare to (maybe you've already referenced it). With an A on the body tag. And some comments from your friend Alan T. Post #20 has the picture of the body tag. None of the engine though. Note that the OP does not say it's an L20A engine, he says it's an L20. Implying (to me) that there was no A stamped on the engine.

http://www.classiczcars.com/forums/misc-s30/14433-information-about-very-rare-s30.html

[Zed Head]

Another - Post #6 (looonnggg thread). Again, no engine picture, just the body tag. By the way, could you link to your pictures for comparison? Might as well tie all of the Fairlady's together in one thread. Build your own case.

http://www.classiczcars.com/forums/misc-s30/16660-gotta-sell-my-69-fairlady.html

[Zed Head]

Here's a 72, but the engine's been swapped - 1 tuff z: 1972 Fairlady Z-L project! - S30 Series - 240z, 260z, 280z - HybridZ

[Zed Head]

Here's another Fairlady topic. More stuff.

Fairlady Z ID help - S30 Series - 240z, 260z, 280z - HybridZ

[Kerrigan]

Found this really interesting interview write up, The following is a professional translation of the article that reports an interview with Mr. Iida, the man that designed Nissan's first OHC, 6cylinder engine, the L20.

Nissan L20 Engine Design

And this one; interesting if you have not seen it already.

Nissan/Datsun L Series Engines

[Kerrigan]

That's a great idea, Zed. Thanks. No, I'm serious. Just an Irish/Scot and you know how we are ... at least the English do ... we never give up.

[djwarner]

Since no one else has mentioned it, you might want to check out Carl Beck's website: the Z Car Home Page

In particular, he has a history on the L series engine that makes for good reading.

[Kerrigan]

Thank you. The cooling setup illustration on his site shows it's an L20A, stamped or not.

That settles that question.

Edited June 22, 2014 by Kerrigan