1970 Engine?

[NapaBill]

This thread got me curious enough to have a look at my numbers. All the numbers are real easy to see with the freshly painted block on an engine stand!

My car is HLS30-07715 with a build date of 7/70. The (matching) engine # is L24 010878. The casting number is E31 0660K. While that may indicate a June production for the block, the numbers don't appear to mesh with the schemes being proposed.

Oh, and the car was originally titled as a '71, and does have the "NISSAN 2400 OHC" cam cover.

[lonetreesteve]

Bill,

Your block casting date of June of '70 would make sense, since the build date is 7/70. Let's try to decode your block #0660K: I would assume that the "0" stands for 1970, the first "6" (or second "6" stands for June), the K for 11th day? I know a lot of the american engine blocks use letters for weeks of the month and sometimes days, not sure what Datsun did. Do you know or does anyone else know how to decode these casting numbers?

[kats]

Hi,

Today I show some car's (Z432) casting code on the engine block.They are

not L-series engine, but they will give us some good points.

They seem to me they are telling exact day of when they were made/or born.

The way of casting method looks same like L-series engine in 1969, but I think after 1970, S20 engine is little bit more specifically telling date.

My Jan 1970 Z432 has

S20-000884, the code is 9 3 14 56.(1969 Mar 14th, what does 56 mean?)

Mr.Watanabe's Dec 1969 Z432 has

S20-000850, the code is 9 3 18 ?? (1969 Mar 18th,last 2numbers hidden by oil and dust)

I am surprised S20 engines were made(I should say "Casting", may not be "stamped serial") well before Z432 went on the assembly line.

I checked some S20s for sale at the Mr.Moroe's shop

S20-001290, the code is 9 6 24 37 (1969 Jun 24th, what does 37 mean?)

S20-001839, the code is 70 5 27 21 (1970 May 27th, what does 21 mean?)

S20-00????, the code is 71 4 2 2 (I for got take a picture of serial number)

S20-002615, the code is 72 3 6 23 (1972 Mar 6th, what does 23 mean?)

These are just my guessing.I think casting code is telling the day, then serial number was stamped.

So, sometimes they are not in sequence among them.

I think it is possible I will find a 1969 Jun 18th(my birthday) S20 engine,if I am lucky. Must be somewhere.

What do you think of it?

kats

[Carl Beck]

HI Kats:

Interesting information you have presented.

Wasn't the Skyline GT-R introduced in Feb of 1969 with the S20 engine. If so then Prince must have been casting production blocks several months before that.. They must have started production of the engines in 1968 sometime. I recall Mr. Matsuo writing that he was told to use the new Prince S20 for the JDM S30, in Aug. of 67.

Why bother to put casting codes on any casting? Usually it is done for Quality Control purposes. If later a problem is found with a casting - you have a record that could lead you to the person that did the job, or the batch of castings that were cast at the same time, or with the same lot of cast iron. That way you can try to find out if the problem was caused by the person involved, or by the materials used or by some process step that was or wasn't followed correctly.

Normally castings of any kind in a production environment - are not cast one at a time. Usually they are cast in larger batches. It takes a huge amount of energy to melt cast iron to a liquid form so it can be poured into waiting molds. If the casting marks track the castings down to the specific day - then the last two numbers might be the sequence number for the casting made that day, or they might be to identify the specific mold used.

If the last two numbers identify the specific mold used - you would know who made that mold. If that person made mistakes in his molds - the entire batch cast that day might not have been bad.. if the problem shows up in several different molds made by different people - then the problem might be in the mix of the cast iron used that day..

So maybe:

9-6-24- 01

9-6-24- 02

9-6-24- 03

9-6-24- 04

9-6-24- 05

9-6-24- 06

9-6-24- 0x.....

9-6-24- 50

The block Serial Numbers are stamped into the block later - so they could easily be out of sequence with the specific casting numbers.

Just a guess for fun....

Carl B.

[kats]

Thank you and That is right, Carl

The GTR made a debut Feb 1969.What I was surprised is why Dec 1969 Z432did not receive Nov or Oct S20? For me it is very interesting Mar S20 is way before for Dec Z432. My explanation skill is poor, sorry always.

I hope more owners put information here, it is fun to see compare chassis and engine number with casting code .Especially owners in the U.S. you all have build date tag,that will be more fun.

I think L24 was first applied to 240Z,but relatively they are big number (like L24-002xxx) as a begining of production.

Is it possible they are same block L20 and L24? After having a block,were they boring for 2400cc or 2000cc then stamp "L24-00xxxx" or "L20-xxxxxx" ?Can we see something from reading casting code of them?

:)

kats

[Carl Beck]

Thank you and That is right, Carl

The GTR made a debut Feb 1969.What I was surprised is why Dec 1969 Z432did not receive Nov or Oct S20? For me it is very interesting Mar S20 is way before for Dec Z432. My explanation skill is poor, sorry always.

Hi Kats:

Your explanation is very clear.

I believe it was quite easy for block castings and finished engine blocks to be mixed up - as they were moved around the factory, sent from the production lines, to the shipping docks and then shipped out to the assembly plants for installation in the various vehicles. No one was paying attention to the casting dates or finished block serial numbers at that point.

For a time - I worked on the production lines and then in the shipping department of a manufacturing plant - believe me - the fork lifts running around - picking up pallets of finished goods - would move them all over the place and in a very random order - before they got loaded on trucks, or in train box cars for shipping. Very easy to get them all mixed up..

I hope more owners put information here, it is fun to see compare chassis and engine number with casting code .Especially owners in the U.S. you all have build date tag,that will be more fun.

I have collect for decades - VIN's with original engine serial numbers for the Datsun 240Z's.. but haven't recorded all block casting codes. For the most part the L24's only have two different codes as I recall.

I think L24 was first applied to 240Z,but relatively they are big number (like L24-002xxx) as a begining of production.

Is it possible they are same block L20 and L24? After having a block,were they boring for 2400cc or 2000cc then stamp "L24-00xxxx" or "L20-xxxxxx" ?Can we see something from reading casting code of them?

I believe the L24 was used in a larger sedan and a commercial truck as well as the Z. The Datsun 2400 {GL130}/Nissan Super Six and Personal Deluxe Six are listed in the FSM. Maybe they got the first few batches of the L24's.

The 1970 L20/L24 Factory Service Manual shows a picture of L24-107. So I would guess that they started the serial numbers at L24-00001.

The L24 and L20A are two different castings of the same basic block. You can not bore a 2.0L with a bore of 78mm - out to 2.4L with a bore of 83mm - and have any cylinder wall thickness left. So the L20A had to be cast with smaller cylinder bores than used in the L24's - to begin with.

So far the earliest L24 block number reported for a 69 production Datsun 240Z is L24-2079 found in

HLS30 0042, but we have only found about 166 of the first 543. So it is quite possible that much lower serial number blocks were used in the Z's.

FWIW,

Carl B.

[kats]

Hi Carl,

Thank you for telling us your experience, I can imagine how manufactures were doing in the factory.

Yes , the L24- 107 , let's find out what the casting code is.

Seems to me 9 2 1 2 4.

And now I remember L20 block has E30 on the block for an early S30.

Early L24 has E31, yes they are different from begining of casting.

I believe a nice siliver 1969 Fairlady-ZL(L20 engine) still owned in the U.S.,

I want to see its casting code on the L20 block.

kats

[spitz17]

Wow! Very nice, indepth explanation as usual Keep it up guys...

[Mike B]

Hi Kats,

Here are some casting codes from some of my early cars and parts cars:

HLS30-00032 10/1969 production: L24-2130 9828G August 28, 1969?

HLS30-00210 11/1969 production: L24-2396 9901D September 01, 1969?

HLS30-00331 11/1969 production: L24-2585 9X04C ????

HLS30-01590 01/1970 production: L24-3652 9X04F ????

Some of these were kind of hard to read, but I think the information above is correct. I'll see if I can post some pictures this weekend. Not sure what the 9X means. I have HLS30-00237 in storage away from my house and I may not get there again for a couple of weeks, but I'll post the casting code when I get a chance.

-Mike

[astrohog]

that last number or letter code could be the time frame that the block was cast on the given date. Alot of our food products are stamped at packaging with a date code that can include a letter code (usually corrsponding to the HOUR, or shift? it was packaged), allowing one to really narrow down the window where that particular item was manufactured.

just a thought...

Regards,

Jeff

[kats]

Thank you everyone,

Mike,could "X" indicate Oct ? 9X04C and 9X04F they are making me think of that.

More earlier L24 has 99##@ and next groupe would have 9X##@.

I tend to think they used X for Octber, Y for Novenber, Z for Decmber.

I am waiting some reports about the casting code which has Y and Z.

The casting craftman did not want to add an extra digit in 1969?

How about this,let's say an block was made on 1969 Nov 11th,and it has "I" at the end,

The casting code could be "91111I"

Is not this easy to be mistaken Jan 11th or just dificult to read out is it?

I think there will be "9Y11I" ...

kats

Edited October 1, 2010 by kats

[Carl Beck]

To Recap what we have so far in this thread..and update as we proceed...

<pre>

L24 107 E31 92124 FSM

L24-2130 E31 9828G 10/69 HLS30-00032 Mike B

L24-2396 E31 9901D 11/69 HLS30-00210 Mike B

L24-2465 E31 9901F HLS30 00215 mdbrandy

L24-2585 E31 9X04C 11/69 HLS30-00331 Mike B

L24-3260 E31 9901A 12/69 HLS30-00587 Carl B

L24-3652 E31 9X04F 01/70 HLS30-01590 Mike B

L24-4375 E31 9Y01A 02/70 HLS30-01704 JonnyRock

L24-004621 E31 0126C 01/70 ???? BonziLon

L24-005562 E31 02121 03/70 HLS30-02156 Kats

L24-005757 E31 0327B 04/70 HLS30-02725 ol'red70

L24-05778 E31 0320A 04/70 abas

L24 010878 E31 0660K 07/70 HLS30-07715 Napa Bill

L24-011821 08/70 HLS30-08323 daddz

L24-026313 P30 1109A 01/71 HLS30-19867 zztom

L24-027116 P30 1616L 01/71 HLS30-20419 AZ-240z

L24 O27310 P30 01/71 HLS30-20390 deadflo

L24-032875 P30 03/71 HLS30 25734 lonetreesteve

L24-039190 P30 1408a 05/71 HLS30-31306 mlc240Z

L24-123315 08/72 HLS30-98122 ChrisA

</pre>

FWIW

Carl B.

Edited October 5, 2010 by Carl Beck
add engine #4375