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zeiss150

L24 horsepower

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    Wow I started this post in December of last year! So here is an up date on my 72 L24... I't blew up! I had to do a total engine rebuild. When I had my E-88 head rebuilt the rebuilders messed it up and it "poped" a valve seat. If you didn't know that is really bad for an engine:stupid: So since I was doing a rebuilt, I figured, what the hell I'll go for it and I jumped up to and L28 N-42 combo with headers 2.5 inch exaust, dyno max muffler, SU carbs with SM needles, K&N air filter, Electronic dizzy, performance cam and valve train in my N42 head. Now I still haven't had it dyno'd but I can tell you that It feels way faster than my L24. Oh yeah I also bored over the engine .020, and had the entire rotating mass ballanced, right down to the clutch pressure plate. I figure that If a stock l28 was producing 142 at the rear wheels then I should be close to 175 HP at the RW. If I close my eyes click my heals together and hold my breath maybe I'll get 180 RWHP. Anyone think I'm smoking crack!!!?????

    If anyone has my set up and has had it dyno'd I would love to see the results. Thanks for the interest in the post guys!

    Rock on Z people!

    Matt-

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    Does anyone know the Gross hp nissan plated to the 280C (single carb) or the 280ZX fi ?

    Just wondering because if I was to register a 240Z with a L 28 at Vic Roads will they make me get an engineers report because of the 10% capacity increase rule.

    Steve

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    Like someone from Vicroads would know it's a 2.8!!

    If you want the lower output of the 2, I'd go the 280C - asthmatic head, single carb.. blah blah blah.

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    My sentiments exactly my insurance company has no idea about the L28 on my car or the bigger valves, cam , electronic ignition. There's just no point telling them, they will charge you more and i doubt for a second anyone would know who isn't into Z's or Datsun's.

    L24 L28 it just looks like another engine number.

    I only told them the obvious the wheels and exhaust.

    Vic roads wouldn't know any better either.

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    Well the L28 On a 79 and up 280ZX had Net RWHP of 135 because of all of the smoge regulations in the US. The 78 and earlyer 280Z brough 149 RWHP (net). Here is a link http://www.edmunds.com/reviews/generations/articles/100641/article.html

    So the real plan should be to take All the smoge "crap" off an L-28 and spend some money on some modes and hold on for the ride.

    Rock on Z people!

    Matt-

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    Originally posted by zeiss150

    So the real plan should be to take All the smoge "crap" off an L-28 and spend some money on some modes and hold on for the ride.

    That's EXACTLY where I'm headed next!!! But, :tapemouth don't tell anyone.... especially the Mustangs!:classic:

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    Originally posted by beandip

    the large 21/2" plumbing will loose you low end power and torque.

    Thats what I keep hearing too. That isn't my experience.

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    Does anyone have RWHP specs on my engine build up? A link would be good, or another site member... anything???

    Phred? do you have any info?

    How about you bean dip?

    Rock on Z (and Zed) people!

    Matt-

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    From those figures a L 28 could be seen as compairable to a L24 in hp given smog junk.

    With Vic roads its a lottery who you get. I changed to a 2lt in my 1600 race car, rocked up to the inspection 3.5 camber, twin webers, race seat, stripped interior, climbed out of the rollcage looking at the inspector thinking I haven't got a chance in hell, but he just lifted the bonnet checked the new numbers said nothing. sweet.

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    Matt wrote earlier:

    >Well the L28 On a 79 and up 280ZX had Net RWHP of 135 because of all of

    >the smoge regulations in the US. The 78 and earlyer 280Z brough 149 RWHP

    >(net). Here is a link http://www.edmunds.com/reviews/gene...41/article.html

    Hi Matt:

    First - I'm sorry to say that who ever wrote that article - really didn't know much about the Z Cars. Way too many factual errors there.

    Second - he reports 135 HP ... not Rear Wheel HP.

    Matt Wrote.. later...

    >If anyone has my set up and has had it dyno'd I

    >would love to see the results.

    I have an L28 bored 0.020 over, Euro Flat Top Pistons (+2cc's), Nissan Cam Kit, 72 E-88 head with 280Z valves un-shrouded, Uni-lite ignition, triple Webers (40DCOE's with 38 chokes), static and dynamic balance...

    Admittedly neglected.. not "fine tuned" for years.. but running "OK". I took it to a local club's Dyno Day. There we ran about 15 cars for the day on a Dyno-Jet (Tampa - almost at sea level).

    Car #1

    Pure Stock 77 280Z with 115K miles, well cared for and

    well tuned.. 119 RWHP (a good baseline for the dyno and day)

    Car #2

    Rebuilt, 76 280Z with every type of bolt-on available.. 121 RWHP

    This car had larger throttle body, headers, MSD ignition, rising rate fuel regulator, K&N air filter, free flowing exhaust... etc. It had been driven about 3K miles after the rebuild. (shows the difference in quality between a factory engine and rebuild by most other shops)

    My car ..... 139 RWHP With a fresh tune, I'm sure we could have picked up a few more HP... but nothing drastic. Might have got it up to 145 at the rear wheels. (that's about 175HP at the flywheel if you use 20% driveline loss).

    At one time I had the dyno run sheets for the above, somewhere on the server - but don't see them there now. I'll keep looking..

    If your looking for streetable performance today - and want to stick with the in-line six -the ONLY way to go is with the L28 Turbo.. running 11 lbs of boost or less.. it's pretty easy to get 250 RWHP .... You won't get anything close to that on street gas running under 10.5:1 compression in an naturally aspirated engine.

    FWIW,

    Carl

    Carl Beck

    Clearwater,FL USA

    http://ZHome.com

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    Earlier I wrote:

    >Dyno runs with the air cleaner top and filter removed

    >show a gain of about 5 to 7 HP.

    Correction.. oops.... now that I review the dyno sheets... that should be 3 to 4 HP gain with the stock air cleaner top and air cleaner element removed (you have to leave the air cleaner base on because it contains the air horns).

    See: http://ZHome.com/rnt/Dyno/KThomasHeaders.htm

    sorry..

    Carl

    Carl Beck

    Clearwater, FL

    http://ZHome.com

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    Originally posted by HKSZ

    Does anyone know the Gross hp nissan plated to the 280C (single carb) or the 280ZX fi ?

    Just wondering because if I was to register a 240Z with a L 28 at Vic Roads will they make me get an engineers report because of the 10% capacity increase rule.

    Steve

    What about the fact that the same chassis/brakes/suspension was the home to an EFI L28 from 1975 onwards on other parts of the world? Does that help your cause?

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    Ben I reckon every 2nd 240Z in Victoria has a L28 in it .

    May have to ask some of our friends across the pond for some literature if they start getting narky at rego.

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    Originally posted by HKSZ

    gettting narky at rego.

    Hey HKSZ, why is the DMV so picky about what engine when you register the car?

    I have a L28 in my 240 and the DMV could care less, they just want to know how many cylinders and what fuel it burns.

    Curious,

    Chris

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    Usual hoops you have to jump through.

    Each State Gov is different, but 10% Power increase over factory standard is a "modification" and requires an engineer to pass it, same for adding a turbo, multi carbs.

    Biggest problem is that it could void personal injury insurance.

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    Originally posted by HKSZ

    Each State Gov is different, but 10% Power increase over factory standard is a "modification" and requires an engineer to pass it, same for adding a turbo, multi carbs.

    I can see some reasoning behind this, don't want some speed-freak putting 800 hp into a car that could barely withstand 150 hp! Or it's just more Gov't control....:finger:

    Anyway, is there some sort of power rating test that they apply to vehicles on a regular basis? How do they know that you've swapped an L28 in place of the L24? Both engines are visually identical, so if you stick with carbs on the L28, how would they find out?

    Here in Texas, most places won't even look under the hood. And they never ask questions about the car. They just want to know if the lights/signals work, wipers, brakes, horn, general stuff like that.

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    Well in most cases they don't know any better. However when it comes to an accident and insurance company could be very picky and find out stuff like this.

    My 240z in Victoria has an L28 nobody really knows either. I am taking a slight risk but if I was to tell them every modification done to the car insurance would be ridiculously high. Probably higher than a car with a turbo and more power just because it's an old sports car and I'm young.

    I would just say L24 and L28 are different block castings nothing to do with capacity or to my knowledge anyway :cheeky: hint hint.

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    You can fit alternative compnents into your L24 block in accordance with ADR's and end up with 2.8L. Same with carburettion - the car will still comply with ADR26 with tripple Mikuni's, extractors & a modified head. Doing this to a 260Z (ADR27) though is a different matter....

    When I planned on legalising my L28ET into R30 Skyline swap, it required engineering, but the conversion I'm doing now - RB30E just needs an engine change notification.

    The L28ET into 240Z was an inspection matter (as I've previously discussed).

    Another thing in your favour is the availability of the correct engine for your car, finding a replacement 240Z-spec L24 iss almost impossible, but an L28 is easy to find.

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    Matt wrote earlier:

    >Well the L28 On a 79 and up 280ZX had Net RWHP of 135 because of all of

    >the smoge regulations in the US. The 78 and earlyer 280Z brough 149 RWHP

    >(net). Here is a link http://www.edmunds.com/reviews/gene...41/article.html

    And then Carl Beck wrote

    >First - I'm sorry to say that who ever wrote that article - really didn't know much about the Z Cars. Way too many factual errors there.

    OK Something Ive been wondering about for years. Nissan changed to using net HP numbers in 74 .

    Then the first 280Z's are rated at 149 HP, but why is the 77 Z rated at 170HP?? Does that engine really have more power? Looks like the same engine as the earlier 280, and the performance specs seem to be the same as well.....

    Another question. my71 engine plate shows the power at 150 at 6000RPM. Why do some sources show the 240Z power peak at 5600 rpm??

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