1970 Engine?

[Carl Beck]

Hi Andrew (Everyone):

As this thread had comments related to information in addition to the original question.. I'll tell you what I know, and belive to be true, at this point.

Nissan only had one production line for the L24 engines. So there is only one series of numbers stamped into them. The engine "serial" number indicates the order the complete long block came off the engine assembly line in series.

So L24-060039 is the 60,039th engine produced. It would have been installed in a 240-Z built in Oct. 1971 (10/71). The 1972 Model Year 240-Z's started production 09/71 at Chassis Serial Number 46000. (however there were a few Series II 1971 Model Year Z's produced during this change over period also).

As someone mentioned - the L24 was used in more than one Nissan Model in addition to the DATSUN 240-Z. So there are gaps in the series numbers of engines used in the Left Hand Drive 240-Z's. Some engines went into the Right Hand Drive HS30 series models after Jan. 1970 (as well as other Nissan Models). So while the HLS30 and HS30 cars had a different set of Chassis Serial Numbers - the L24 had only one set.

Engines moved from the engine assembly line - usually in what would seem to be lots of 200 or more at a time, to the Z assembly line. Nissan "Shanti" (a guess at the spelling of that, without looking it up) - was actually a sub-contractor to Nissan Motors. They built production models such as the 1600/2000 roadsters, in limited quantities, for Nissan Motors Ltd in Japan. In Oct. of 1969 the Z Car production was started there (Shanti), on the same assembly line as the 2000 Roadster..

To Date, the lowest engine serial number, installed in a 240-Z that we have located and verified is L24-2079 and it was installed in HLS30 00042 in Oct. 69. (still ran fine the last time I started it up - sold #42 to a friend of mine last year).

A specific engine, is specific to a specific 240-Z. Because each 240-Z had a Data Plate screwed to the right hand shock tower, under the hood. That Data Plate Lists the VIN of the car and the original engine serial number (thus tieing the two together and referred to as "matching numbers" if the Data Tag matches the Engine serial number stamped in the block).

All 240-Z's coming to the North American Market (and that was about 98% of them) had an additional Data Tag on the Drivers Door Jam, that lists the Date of Manufacture of the car and the VIN number. This tag was required by US Regulations to be attached to all Vehicles sold in America upon completion; so that US Motor Vehicle Safety (MVSS) and Emissions Standards could be enforced - as they are both enacted into law by "Date Of Manufacture".

The Right Hand Drive 240-Z's did not get the Date of Manufacture stamped on the cars. However it is possible to determine (within a month or two at least) their actual production dates, based on cross-referencing their engine numbers, with the dates of Manufacture of the Left Hand Drive 240-Z's and their engine serial numbers.

>2-4-T-Z Man wrote:

>IF IT IS AN E-31 YOU HAVE A 1970.

>IF IT IS AN P-30 YOU HAVE A 1971-1973.

Does "A 1970" mean that the item was "produced" during calendar year 1970; or does that mean Model Year 1970? Model Year 1970 240-Z's were produced from Oct. 1969 into Jan. 1971.

In general I find that the early L24 blocks do indeed carry a P31 casting. But so far I have not found a specific date at which the casting numbers change - consistently.

The Casting Numbers - on most parts were used for Quality Control purposes within the casting process itself. They simply help identify raw castings as well as which casting lines and/or stations any specific raw casting came off of - so if the quality of the cast parts varies - corrections can be made. Raw castings are usually processed through machining steps before they actually become a useful "Part" at a specific point in time. So any one casting could have been farther machined, to produce several different specific part numbers.

2-4-T-Z Man, I would be very interested to see any documentation from Nissan that ties a casting number to a date of manufacture or an absolute change over date. While we may be able to use casting numbers as a "general reference points" or "rules of thumb".. I wouldn't depend on them to indicate anything other than that which Nissan used them for. I will readily admit that in many cases it would "seem" that casting numbers changed, on certain castings, past certain points in time.. In this case however the best evidence of the date of production of this engine, is the Engine Serial Number. (of course re-stamping engine serial numbers is something that has been done on many Chevy's over the years;-)

Nissan used Engine Serial Numbers for two purposes. All Technical Service Bulletins reference the engine serial number because that pins down the specific engine at which any manufacturing changes were made, or when any manufacturing defects entered the process; and for warranty purposes it ties a specific engine to a specific VIN.

It would seem that if engine serial number 60039 has a P--31 block casting.. they must have found an old block laying around - or someone else has restamped the serial number.. Yet another Z Car oddity... and we may have to just accept that this might be one of them..

FWIW,

Carl

Carl Beck

Clearwater,FL USA

http://ZHome.com

[2-4-T-Z-MAN]

Carl,

Thanks for some very detailed information. I wondered when you would see this topic and jump in.

I have to say that by no means am I an authority on the Z.

Every day is a learning experience.

Your answer that this car , based on the 60039 #, indicates that it was built 10/71 making it a 71 confuses me. I'm not disputing your information, it just seems that there is more information out there than can be assimilated and come up with a simple method of determining a vehicles model year, other than the title.

It was my understanding that the E-31 block made it a 1970's car and if it had a P-30 the car would be a 71-73 depending on build date.

Now the 60036# issue places a car with a E-31 block as a 1971. Which lonetreesteve's title states. Whats up?

If he checks the plate on the shock tower and finds that the numbers match, would that eliminate the prospect that someone put an earlier engine in his car?

I have since gone to an article you wrote for the Internet Z car Club back in may 2001.

In that article you made mention of two cars, one having a later build date than the second. The car with the later build date was titled as a 70 model while the one with the earlier build date was titled as a 71.

So do we just go by the title information as to what year vehicle we have? Is this entire topic just semantics? There just seems to be so much conflicting information.

[Carl Beck]

2-4-T-Z Man replied:

>Carl,

>Thanks for some very detailed information. I wondered when you

>would see this topic and jump in.

>

>I have to say that by no means am I an authority on the Z.

>Every day is a learning experience.

Hi Z Man (everyone):

Every day is a learning experience for all of us.

>Your answer that this car , based on the 60039 #, indicates that it was built 10/71 making

>it a 71 confuses me.

Your sentence confuses me. ;-)

I said: "So L24-060039 is the 60,039th engine produced. It would have been installed in a 240-Z built in Oct. 1971 (10/71)."

I went on to say that the 1972 Model Year Z's started production 09/71, during the month of 09/71 there were both 1971 and 1972 Model Year Z's produced ... At any rate being a 10/71 build date - that engine serial number would have been installed in a 1972 Model Year Z build 10/71.

>I'm not disputing your information, it just seems that there is more information out there

>than can be assimilated and come up with a simple method of determining a vehicles

>model year, other than the title.

No mention was made of using the title..(that's another story all together). We are only talking about either "Production Year" (meaning the Calendar Year) or "Model Year".

Here in the US "Model Years" of cars do not run concurrent with "Calendar Years". Normally "new Models" are introduced several months ahead of the end of the Calendar Year.

Actually it is quite simple to determine the Production Date.

a) There was only one L24 engine production line. The engines were numbered sequentially within the series used...

The production of L24's was limited to the production capacity of that single line - only so many engines could have been made each month.

c) All North American Z's have their Month and Year of Manufacture attached to them.

d) All 240-Z's have Data Tags that tell what the Original Engine Serial Number installed in that car is.

From this we know it's not possible to build a complete car "before" the original engine installed in it at the factory - has been produced.

By gathering a large statistical sample - patterns of engine serial numbers can be associated with specific build dates from the cars they were installed in. So you wind up with narrow ranges of Chassis Numbers lining up with narrow ranges of Engine Serial Numbers. Within these narrow ranges, engine numbers do not match in perfect sequence with the chassis numbers.. but they all do fall with narrow ranges of each other.

We know that the engine's did not get installed in perfect sequence with the Chassis Numbers of the cars - none the less - within a month or two - and within blocks of engine serial numbers - the progression of the engine serial numbers do match the progression of the chassis numbers.

When we compare the above observations with the information the Factory Service Bulletins and the Factory Parts Catalogs provide - we see that they support one another.

>It was my understanding that the E-31 block made it a 1970's car and if it had a P-30 the

>car would be a 71-73 depending on build date.

Here you have to specify - are you talking about "Production Year" or "Model Year" cars?

Cars built during Production Year 1970 were sold/titled as both 1970 and 1971 Model Year cars. Cars built during Production year 1971 were sold/title as both 1971 and 1972 Model Year Cars... etc etc. So to be clear in your meaning, you have to be specific in your terms.

If it is your understanding that all L24 blocks cast in Production Year 1970 had casting number E31 cast into them... then they might be found in both Series I and very early Series II cars - with Model Years 1970 and 1971. Because a block cast in the last week of 12/70 could easily have found it's way into a car built in the first few weeks of 01/71 or even 02/71.

Then my question is, upon what information is that understanding based?

I will agree that in general and broad terms - it is most common to see the E31 castings in series I cars..

>Now the 60036# issue places a car with a E-31 block as a 1971.

The 60039 # places a car with an E31 block in a car that would have been "Produced", along with several thousand others.. in 10/71. It most likely would have been a 1972 Model Year Z Car. I agree that in general those two pieces of data don't line up correctly.

So far we have engine serial numbers between 57741 and 64101 installed in Chassis Numbers HLS30 46675 and HLS30 49806 all with 10/71 Dates of Manufacture. (remember that not all L24's went into Z's... large blocks of them went to other production models).

#60039 puts that engine almost right in the middle of that group. Is it "possible" that #60039 got pushed to the side, left behind at the engine factory and somehow got out of order, somehow delayed and put in car built 11/71, 12/71 etc... Yes it's possible.

Would it be possible to install that engine number 60039 in a car made 10 months earlier.. say in 12/70?... when all the engine serial numbers from those dates were between 15xxx and 17827?.... knowing that the numbers were assigned sequentially in the series?... NO NOT Possible.

>Which lonetreesteve's title states.

Lonetreesteve has no title for the engine he's asking about.

I get the impression from Lonetreesteve's writing - that he has an extra engine -- not installed in a car at all. It was just a spare engine - which the seller was told it was from a 1970 Z.

>Whats up? If he checks the plate on the shock tower and finds that the numbers match,

>would that eliminate the prospect that someone put an earlier engine in his car?

He has no Shock Tower Data Plate for that engine.

If he checks the Shock Tower Data Plate for the 71 or 72 Z that he has - then he can verify that either one of them still has its original engine or not.

If he tells us - only the engine serial numbers, from the Data Plates of his Z's - I'll tell him what the Date Of Manufacture is on the Data Plates on the Drivers Door Jam's of his cars.

Or if he tell us only the Build Dates of his Z's - I'll tell him the range of engine serial numbers that were installed in his cars.

If he tells us both the Date of Manufacture and the Original Engine Serial Number of his Z's - taken off the Data Tags...I'll add that data to our data base.. ;-)

>I have since gone to an article you wrote for the Internet Z car Club back in may 2001.

>In that article you made mention of two cars, one having a later build date than the

>second. The car with the later build date was titled as a 70 model while the one with the

>earlier build date was titled as a 71.

That is correct. Within the Series I 240-Z's... there is a huge overlap in how they were sold and titled. There is no question related to when each car was built, nor what the original engine serial number was.

That is because it was up to the Selling Dealer to decide how to apply for a State Title for the car they sold. Nissan does NOT issue Titles, Nissan provides a Manufacturers Statement of Origin (MSO) to the Dealers. The Dealers then take the MOS to their local Dept. of Motor Vehicles and apply for a State Title to be issued. The individual States issue Titles. The reason the Series I cars could be sold as either 1970 Model Year or 1971 Model Year Z's - was because there were no changes in the US Motor Vehicle Safety Standards (MVSS) nor Emissions Standards for cars produced before 03/71. So if the Dealer declared a Series I Z to be a 1971 Model Year Car.. it was perfectly legal to both sell it and title it that way.

>So do we just go by the title information as to what year vehicle we have?

Your State Issued Title -- only shows what "Model Year" the car was sold as. As we know, both Series I and Series II 240-Z's were sold as 1971 Model Year Z's and are titled that way.

Because for 1972 and 1973 Model Years - there were different MVSS and Emissions Standards - they had to be sold and titled as the Model Years that meet the US regulations and so it was no longer up to the dealers to decide.

>Is this entire topic just semantics? There just seems to be so much conflicting information.

Specific terms are very important to watch - both in writing and reading about these cars... yes a lot of the confusion is caused by not using specific terms and semantics.

The specific case here - of having a block with an E31 casting number and an Engine Serial Number that would indicate a build date of 10/71 -is very unusual indeed.

Is it possible that an older E31 cast block get pushed off in a corner somewhere, only to be put back on the engine line 10 or more months later and then finished? I guess it's possible. Is it possible someone re-stamped/altered the engine serial number?... I guess that's possible too...Is it possible lonetreesteve needs to take a pencil and piece of paper with him to write these numbers down.. as he triple checks... it's a good idea ;-)

FWIW,

Carl B.

[2-4-T-Z-MAN]

Carl,

After reading one spacific line of your note I proceded to smack my forehead and go DUH !!!

I reread lonetreesteve's note and realized that I had, in my mind, placed his spare engine in his 71. DUH !!! Total misc. ramblings on my part about the shock tower ID plate, his car's title, etc.

Datsunzgarage.com has an article that talks about how to identify engine and head series.

Brian Little states that 1970 240's have L24s with the E31 block and that 71-73 Z's have L24 with the P30 block.

So this 60039 engine leans to the thought that the above statement is too broad?

[abas]

24tzman/Carl/lonetreesteve

It seems from previous posts maybe the only link to 1970 is the 2400ohc valve cover, from which the PO might have got his dating info from. As far as I know this 2400 valve cover will fit any head, any year, and so cannot help towards dating the age of the block ( Over here we would refer to it as a 'red herring' but I don't know whether that term is in use in the US).:classic:

[lonetreesteve]

Carl.

Thank you for your most informative reply! Unfortunately, I don't have the data plate. The engine was a "throw in" along with some other misc. 240z parts with a '71 240z that my son and i purchased a couple weeks ago (which has matching numbers by the way). As I mentioned earlier, the valve cover has the early '70 "Nissan 2400 OHC" valve coveron it and not just the Nissan OHC" that you see on later '70 and the '71-73 240s. I was told by a very-well respected 240z shop owner here in the Denver-area that valve cover could be worth in the neighborhood of $500.00 US by itself. Is that true? are these covers that rare and that much in demand?

MDBrandy,

Yes, I am getting the stamped 060039 number off the raiseed area next to the stamped L24 on the upper portion of the block below the head, just below the head. The E31 on the lower portion of the block is raised lettering.

As Carl mentioned, just another strange, quirky mystery with the 240Zs that we all love!

Steve

[Carl Beck]

2-4-T-Z-MAN replied:

>Datsunzgarage.com has an article that talks about how to identify engine

> and head series.

Hi Z Man..

Datsunzgargae.com - doesn't come up on my Browser...

I have the URL for Brian's site as: http://geocities.com/zgarage2001/

Is there now a different one?

>Brian Little states that 1970 240's have L24s with the E31 block and that

>71-73 Z's have L24 with the P30 block.

Yes, as I said - that has been generally true in my experience also if we are talking about the "Production Year" of the part, and not the Model Year of the Car. That is why having an E31 block show up in a car that would have been produced 10/71 is interesting... if not odd.

The truth is, I don't know of any broad effort to link casting numbers to engine serial numbers or published start/stop dates from Nissan. In Brian's as well as my case, it's just a general observation based on limited personal experience.

In the case of Engine Serial Numbers matched to VIN's and Production dates - I've been actively gathering that data, on hundreds of cars for the past 15 years. So I believe we have a pretty good statistical sample with high confidence levels.

>So this 60039 engine leans to the thought that the above statement

>is too broad?

It would lean toward the statement not being true in absolute terms.

Brian has put a lot of work into his web site and "in general" it answers a lot of common questions that people have about their Z's. However I must admit that I find many statements to be misguided if not factual errors - through-out the site - most are small and some would say insignificant in the overall scheme of things... but they Pop out at me..

I keep meaning to write Brian about several of them -but then, I have a hard enough time keeping up with the Z Car Home Page.... We all have to be careful to verify sources of information on the Net... much of it is simply stated in a confusing or misleading way, some of it is just simply opinion presented as fact.. and some of it is simply incorrect to begin with..

everything taken with a grain of salt..

FWIW,

Carl

[deadflo]

For what its worth.

My car is one of the last series ones, HLS30-20390, Its door jamb plate shows a build date of 1-71.

So it really was built in 71 although it is a series one.

It has a matching number engine L24 O27310.

The matching engine is a P-30 block.

I wonder if its one of the first S30's with a P-30 block?

Also regarding Brian Littles webpage his timeline shows the E-88 head starting in 71, and the copy says the e-31 head was on "early 70" cars. My car has an e-88 head but again its a series one car.

I cant verify the head is original but there was some paperwork with the car about a head rebuild in the late 70's and not a lot of miles on the car since then. Again i cant confirm it is the original head though....but I see confilcting info around about when the e-88 actually was first used. Whats the scoop?

[abas]

Originally posted by lonetreesteve

I was told by a very-well respected 240z shop owner here in the Denver-area that valve cover could be worth in the neighborhood of $500.00 US by itself. Is that true? are these covers that rare and that much in demand?

Steve

Steve

2400ohc valve covers are fairly sought after and come up on ebay fairly regularly. They usually go for $50-$125 right now but those prices have been increasing over the past year in line with most other series 1 parts. I don't know of anyone who has paid $500 for such a valve cover.

hope it helps

Andrew

[Carl Beck]

Deadflo wrote:

>For what its worth.

>My car is one of the last series ones, HLS30-20390, Its door jamb

>plate shows a build date of 1-71.

Hi Steve:

Yes - the last one verified so far is HLS30 020438 ( I think).. with engine

number L24-26808.

>So it really was built in 71 although it is a series one.

Yes - the Series I's were built along with the Beginning of the Series II Z's in Jan. of 71.

>It has a matching number engine L24 O27310.

>The matching engine is a P-30 block.

>I wonder if its one of the first S30's with a P-30 block?

Could very well be - could be that in order to keep up with the demand for Z's Nissan had to increase engine production, and thus simply added another "block casting station" and used P-30 to differentiate it from the E-31 block casting station. (Casting Numbers were mostly used for Quality Control tracking)

Nissan increased production of the 240-Z from about 18,000 the first year to about 32,000 the second year! So they had to increase the production volume of the engine line as well.

>Also regarding Brian Littles webpage his timeline shows the E-88 head

>starting in 71, and the copy says the e-31 head was on "early 70" cars.

This is an example of the small "errors" on the site.

The E31 Head was used on the Series 1 and Series II 240-Z's (1970 & 1971 Model Years, produced between Oct. 69 and Sept. 71).

Brian's site say's that 10,000 cars were made with the E31... Wrong.. More like 46,000 Z Cars were produced and sold with the E31 head (plus about 10,000 other Nissan's with the L24 engine).

The E88 head was introduced on the 1972 Model Year, Series III Z Cars. Although there is some evidence that some heads cast as E88's actually have the combustion chambers cut to E31 Spec.'s with 42.4cc combustion chamber size, instead of the E88 Spec. 44.7cc.

The E88's Production Date starting 09/71. Series II cars were still being produced in 9/71 so during this over-lap period, some 1971 Model Year Series II cars actually got the E88 casting on their heads, but the combustion chambers were still cut to the E31 spec.'s. Likewise some of these heads found their way on the first Series III cars. (as far as we can tell). It's a rare occurrence.. but it has been found.

>My car has an e-88 head but again its a series one car.

>I cant verify the head is original but there was some paperwork

>with the car about a head rebuild in the late 70's and not a lot of

>miles on the car since then. Again i cant confirm it is the original

>head though....but I see confilcting info around about when the

>e-88 actually was first used. Whats the scoop?

On a Series I car you can be sure the head's been swapped So far Brian's site is the only one I've found that claims only 10,000 E31 and only on the "early Z's". Where else are you finding "conflicts"?

Brian says that there were two types of E88's - small valve and large valve.

In fact there were three heads with casting number E88. The 72 Model Year, the 73 Model Year and the 74 Model Year. The 72 & 73 had the same valves, the 72 had 44.7cc volume combustion chambers, the 73 has 47.8cc's. The E88 on the 74 260Z has 47.8cc but with a larger 35 vs 33 exhaust valve.

Brian says - that the 74 260 E88 has the same size combustion chambers as the N42/N47.. wrong. The N42/N47's have smaller size combustion chambers..at 44.6cc.

If you want accurate head information - I'd suggest you get it from the Z Car Home Page.

http://ZHome.com Just look in the Technical Library Section.

FWIW,

Carl

Carl Beck

Clearwater,FL USA

http://ZHome.com

[lonetreesteve]

Carl,

Thank you for the very interesting info and thank you for the link to Zhome.com! I will register our '71 amd '72 240Zs in the next couple days. I noticed that you have #20, that's terrific!!! I saw that #390 (needs restoration) is currently on eBay, item #2479358623.

I also noticed that you have a '72, white with red interior, that's what our '72 is also (#64733, with the engine matching the data plate #081097). My son and I have had a real tough time finding the red interior parts during our restoration process.

With regard to my original post on the extra engine we have with the E31 engine block, E31 head, E88 intake manifold, Hitachi SU carbs, '70 air cleaner, Series 1 valve cover, and the higher #060039 engine number I am still at a loss, everything points to a '70 engine with the single exception of the high engine number. You hve come up with some very good ideas on why this is, but your'e right, it is a strange specimen.

Thanks again and look into #390 on eBay, the seller says that if is not sold, it will be parted out and "sent to the shredder". That would be a shame for one of the rare "500" 240Zs to end up like that.. Maybe one of the classic zcar members may look into saving this historical car!!

[Carl Beck]

Hello Steve:

You know - there is another "possibility" here. The guy that stamped the engine number on that block - could have simply had the die set up wrong... or could simply have put an extra "0" to the right side of the "6"

As for poor #390... I'm afraid it's too far past any economically reasonable consideration for restoration. The rust damage is simply too extensive, better to save another 69 production dated car that has a more rust free body to begin with.

So far - of the first 500 240-Z's produced - we have found 125 of them "still in existence". Of those 125 maybe 40 are in pretty good condition and 85 simply "still exist" needing complete restorations... If he parts out 390 and sends it to the crusher... the number will go down to 124..

FYI - "SEM" (is a Brand Name)... and they produce "Vinyl Paints/Coatings" and "Trim Paints" ("trim" is for applications to metals).. their "NAPA RED" is a dead match for the red interior of the 240-Z's. I've used their products for the last 30 years.. you can dye the seats, it won't rub off (if you follow their directions). Most Automotive Paint and Auto Body Shop Supply Companies carry it.

regards,

Carl