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Has anyone ever seen something like this before?


Chuck_S30

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I was pressure washing my motor today before dropping it in, and after finishing this intake/exhaust side of the engine, i noticed these big white markings. At first i thought it was something of unknown substance that had melted onto the block years ago, but as i cleaned it up more and more i seen it was a set of numbers and letters. I have not seen anything like this before..(I'm only 20 so i have not really seen anything) it looks like maybe some kind of service number? i know this motor was never picked up from the junkyard as the PO bought the car brand new, didn't pass smog one year, and parked the car. im thinking that it might be rebuilt? im not sure any one else got any idea that can enlighten me?post-40943-0-11697000-1377382325_thumb.jpg

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Nissan stamped/etched the engine ID number in to the car's ID plate on the fenderwell up through 1976, maybe into 1977.  Stopped for sure in 1978.  Find the serial number of the engine, stamped on a pad at the top of the block between 5 and 6 cylinders and compare.  The first three symbols are engine size - L24, 26, 28 -  followed by the ID number.  If it's original, it will match the car ID plate.

 

 

Edit - just noticed your sig says 1974.5 260Z L28.  So, if you don't have the car the engine came from, or it's post 76, you're out of luck on the ID plate.  Good luck.

Edited by NewZed
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If this is the car in your signature, it IS NOT the original engine.

To check, look on your ID Plate on the Shock Tower, it will list both your ENGINE serial number and CHASSIS serial number.

 

Yours (260Z) will have an "RLS30-XXXXXX" number for your chassis, and an "L26-XXXXXX" number for the engine. If the engine number matches that plate, you have an original "Numbers Matching" vehicle.

 

Nissan service blocks early on came with no ID on them, the pad under the heater hose connection on the head was smooth. Later, once a stock of rebuildable service cores was available, they switched from "Service Replacement Blocks" to "Nissan Remanufactured" engines.

 

If your specs are accurate, your block will be "L28-XXXXXX" meaning NOT original...and if that transmission. Is a five-speed (you don't say in your post) then I got more news: it's not original for a US Market Car, either.

 

Good news: it's a 260Z, nobody cares!

 

The style of writing IS NOT "Nissan Japan Supplier" style, it is Junkyard Cataloging Numbers on both parts. Chances are it was either steam cleaned and marked before shelving or shipping....or was marked up on receipt in the USA by a Used-Japanese Engine Vendor fr stock control.

 

For DECADES in California it was FAR cheaper and faster to put in a low-miles JDM Replacement Engine ($125 at some points, raising to around $425 due to exchanger ate fluctuations by mid 90's, the last time you could readily and easily obtain real "Used Low Mileage JDM Engines -- 10 year point after model run cessation...road tax and Shaken-Sho killed the population in Japan by that point...) than rebuild the original engine. K Watanabe, Tomic Honda, Mapai International were all in competition selling them. Wantanabe had engines from Nissan's test lab with only Dyno Time on them! L20A engines were brought in occasionally as well. I've found L20A/Y70 Head combos in late model Maximas... all look factory stock because thy were...just in another car originally! Chances are REAL good the PO either wanted more power, or went used-engine at some point from overheating he original engine and made he choice of "L28/5-Speed=$600" over "Rebuild L26 ONLY=$900~1200"

 

Again, it's a 260Z, nobody cares. Don't get hung up on it!

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Oh, and if it didn't pass smog one year and was parked, it's been parked close to 15 years or so... The 260Z hasn't had to pass smog since around 1995-99, which means the used engine replacement is even MORE Credible theory as they were DIRT CHEAP at that point.

 

Or was it 2001? I think I was till on Alabama plates on my 260, but don't remember if it was fees or smog that I was ducking....or simply hadn't changed back yet out f pure sloth...

Edited by Tony D
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Ok first off, sorry my profile ans signature are misleading and i left out lots of information (I will shortly change that). Second im only 20 years old enrolled full time in an Automotive Technicians program so most of my time is spent studying for my ASE's so most of my time and attention is devoted there. Here's the story, i found the 74.5 260z at my grandmas house last year and me having mo car decided to restore it and use it as my daily driven vehicle. The motor was orginal, P30/E88, garbage smog control carbs n36 manifolds. My father being stubborn would not let me junk them for original S.U., triple mikuni, or webers. I spent weeks fighting those dreaded flat tops. The best i could get was an idle at 900 and a drive that was less than pleasant. After much debate he gave in and decided that it was not the most effective fuel delivery system. He opted for the clifford/holley kit. Yes i know that money couldve been spent on triple mikuni or nice rebuilt pair of S.U.s but being the muscle head he is i settled for that, i wont argue with someone whos willing to spend that kind of money for me. So that was that and the car was now operable, but not legally. While i waited to save money for registration and several months of insurance, i stripped the car inside and out, sanded her down and primered , cleaned up the wiring, bought recaro specialists, and MSA victory spoiler and front air dam with cooling ducts.

 

Heres where it gets interesting;

I decided to overhaul all my gaskets, so i pulled the motor (p30) disassembled it and replaced what was given to me in the gasket overhaul set including valve stem seals. Heres where i foolishly did not think AT ALL. I replaced one of the smaller water pump bolts with a new one from a assorted set of fasteners i ordered from eBay from a private seller. Upon doing this i broke of a piece of the block casting, creating a time bomb. I had no knowledge of this and when i was ready to turn on the car, i turned the ignition and was only greeted with spinning of the starter. I could tell that no compression was being created so i did a compression test and lost all compression in all cylinders. This is where i pulled this motor and started looking for another one

 

 

Part 2

 

Down the street was a 79 280zx sitting because it could not pass smog one year due to a fault in the smog system. When i popped the hood i.could clearly see wiring performed by someone who.clearly did not have any.experience just some.extra wire and electrical tape. This is the motor i pulled, junked the fuel delivery, well i still plan on using the EFI manifold for turbo, but cleaned this motor up, used ORIGINAL fasteners, new gaskets and blah blah. I pulled the 5 speed from the ZX as well.So now this is where i stand. A 74.5 260z with a 79 N42 block with n47 head. Sorry for the novel but hopefully this cleared it all up.

 

Thank you for the info, it really has cleared up my question, next time i will be sure to post adequate information

Edited by Chuck_S30
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Which ASE's? Do they still break it all down by systems?

Last time I tested and got patches (somewhere) it was "NIASE"!

Yup, still broken down by systems, A1-A9 for automotive i believe. Went through the Auto Program same as with the OP, passed my A6 in electrical just need to gain my work experience to get the actual cert. IMO one ASE is better than no ASE compared to the actual students in the program who didnt even try to attempt it. Harder than i anticipated given i had no real world experience to help with the questions they had.

 

OP: Goodluck on your tests! Which ones are you planning on taking?

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I actually took them back in 1980 as a high school junior...leg up to the GM Dealer in town. I had a patch! LOL

Back then it was book testing, read the right books and retain it...and you could pass easily.

Over the years they have improved them... They were caught unaware with the "import invasion" relying heavily on domestic stuff only into the mid 90's... It finally started changing as they started hearing from multiline dealers "ASE Means Squat on Imports!"

 

Ahh, the old days...

Edited by Tony D
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Heres where it gets interesting;

decided to overhaul all my gaskets, so i pulled the motor (p30) disassembled it and replaced what was given to me in the gasket overhaul set including valve stem seals.

 

I replaced one of the smaller water pump bolts with a new one from a assorted set of fasteners i ordered from eBay from a private seller. Upon doing this i broke of a piece of the block casting, creating a time bomb.

 

spinning of the starter. I could tell that no compression was being created so i did a compression test and lost all compression in all cylinders. This is where i pulled this motor and started looking for another one

Don't see how using the wrong water pump bolt caused "loss of all compression".  The first part is the more likely cause.  Did you take anything apart to find out the details of what happened?

 

Anyway though, good luck with the wrecking yard 79 ZX motor.  It will probably work fine with the manifolds from the motor you doinked  up with the gasket refresh.

 

By the way, 74.5 still doesn't tell if you have the early small S30 or the later bulkier S30.  It's important for other things, like suspension work.

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I havnt looked into the actual tests yet, i dont wanna overload myself early one thinking about passing certain tests and having to study one certain area and neglecting others. As of right now in class, my engine instructor will give us the "go ahead" and register for this cohort program through the school which pays for each ASE test i take for the first time. I basically want to become a master mechanic. I just make sure to study and read before lectures, get as much hands on experience outside the classroom, wether it be testing my own vehicle for electrical problems i learned how to diagnose, or how to properly clean engine components and measure using micrometers, end play gauges, ect. I dont wanna lag on this program

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