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Nissan L20 Fairlady Z motor


Guest ON3GO

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Guest ON3GO

Queston for you guru's..

 

Would fixing up a L20 Fuel Injected motor be worth it for road racing?

Big bore, short stroke..

Im not looking for 400hp (would be sweet but i know its not bealievable)

BUT i would want enough power to get a Z thats 2200lbs around a track quick enough and wont make me bored to drive it.

 

Im 99% sure im buying this 1976 Fairlady Z RHD thats here in houston.

he rusted threw pretty good but its all there and i just want it lol.

 

Blue Z is done and i have been saving up money to atleast get the Hulk Z here in texas so i can drive it.

Green Z is pretty much done, all thats left to finish it off is little stuff that i dont need yet, + paint but ill be doing that around next year as me and Ed (member on here who is painting my blue Z with me now) are going to be getting a house together and were gonna put a paint booth in the garage.

 

so green Z is also pretty much done, just waiting for it thats all..

 

so this Fairlady Z is next and im deff gonna get it if the guy takes my offer.

And i would like to keep the L20 in there but just beffed up.

 

can these motors takes lots of revs with a well prepped and balanced motor?

can they make around 250rwhp?

it would NOT use a factory computer or really anything factory..

 

did a search but theres really no info at all on these motors.

 

thanks

 

Mike

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Down this part of the world we have a lot of the Fairlady Z from the JDM that have been imported over the years. The L20 are easier to find than L28 these day (the last few 280zx I looked at where in fact just fairladies with the L20e engine). These L20 I have seen all seem to have an E30 head (these are also the same head I have seen on 240K and 240KGT's, these are the C110 Skylines they have L24's and a single carb.)

 

Also we did not get the 280ZXT so most turbo of the L6 here are L20T (from the R30/R31 skylines) stuff fitted to L28s.

 

These heads have small combustion chambers. So with some bigger valves some port work these might give high CR - I don't know most people don't bother with the L20 - just use parts ie rods, turbo manifolds, etc

The Japanese use the L20 rods with custom pistons and LD28 cranks to make their strokers on L28 blocks.

Not sure how much HP these will make but 250rwhp is a big ask if you want it to be reliable at the same time - I am sure you can get this HP but it might be a hand grenade (the pin is pulled it is just a mater of time before it goes off).

 

Even the Japanese replace these engine with L28's if they want performance - so maybe that is a sign that these engine are good for parts only and the reason you can't find much info on them.

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Guest ON3GO

well the car has a N42 or 7 (dont remember) head on it... it is a L20 block though.

i wouldnt mind replacing the engine, infact i want to do a RB26DETT or 1JZ-GTE to it but i like the fact of building and owning a high compression 2.0 straight 6.

it would be mostly for road racing, as for street driving i have my blue Z or my daily driver scion.

 

is there any sites that have spec sheets and etc for these L20 engines?

i would love, LOVE to do tripple webbers or solex's on it but i like and im good with fuel injection so ill stick to that for now.. but who knows carbs or ITB's might see its way on this car.

 

mike

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FYI....I had a L20 in a Fairlady with triple Solex and header etc and it was a dog. Its comparable to a stock 2.0 liter 4 cylinder. Small small pistons...dont waste your time get the L28 block if anything to start with...Just my 2 cents worth...

 

The 800 extra ccs makes it feel like a rocket comparitively...I was running around 17 sec quarters with the L20 and 14.5s NA with the L28 on a 74 2 plus 2 at Carlsbad raceway in the mid eightys...pics on website, the BAT MO Z...

 

Terry

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Guest ON3GO

well reason i wanna keep the 2.0 is high revs if its doable which anything is, and different.

it sorta wont be a street car, want it pure race.

im sure some power can be made out of this motor.

 

anybody have pics of this motor so i can see if this is really what i have.

i didnt have the time or light to see the block casting numbers and etc

 

mike

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Mike its the same externally as the L26 or L28...you have to look on the side of the engine and see what number is stamped on it...L20 etc...Put the L20 crank in an L28 block with L20 Head if ya want more compression...

 

Oh if I remember correctly I did put a L20 head on a L28 and it ran crappy....It was a long time ago though...

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On a side note - I have never seen a P79 or P90 head before (I have not had a good look at any Turbo L Series engines here in NZ). N42 are very common on the JDM L series engines. My L28 out of 1981 Nissan Laurel left the factory with the following block head combo, F54 and N42.

 

I believe these L20e engines in stock form output approx 120hp net (ie flywheel HP). You might find this Fairlady is a S31. These are the same body as the S30 but the trim is different (dash looks the same as the 260z/280z but I believe the angle of the 3 guages is different) some even had electic windows fitted and there were other trim differences. Well that is about it from me when it comes to these JDM fairladies - sorry I can't help anymore.

 

Next week I will visit a ex Nissan Japan mechanic I know and see what info I can get from him.

 

Ok - update he is what I found on a Japanese site re performance from the stock L20e engine

 

"L20E (SOHC1998cc * EGI electrically controlled gasoline injection device): 130ps/6000rpm and 17kg-m/4400rpm"

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Guest ON3GO

thanks man.

 

heres what i no about it.

its a 76 model year

its git 240Z front turn signals and 240Z bumpers

has euro 280Z rear tail lights

its Fuel injected

its got a 260Z/280Z dash

its pretty much a 260Z we have in the states.

has reg roll up windows.

does have the JDM mesh grill.

doesnt have a vented hood

trim plate says its a 1998 (?) cc engine and L20 engine code

its a N42 head if i remember correctly

the head has HUGH piping for each bank, like a easy 2in each.

its a 6 to 1 also if i remember correctly.

engine runs great and PULLS HARD! faster then my old L28E in my blue Z when it was stock and that put down 150rwhp if i remember right.

door panels were a deff 280Z style panels, yet the interior had the 240Z snake skin vinyl trim around the tranny tunnel.

 

mike

 

this is a 6 cylinder right.. cuz it had 6 exhaust ports... if not then i guess it has a swap..

 

mike

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Mike,

 

That sound correct re the look of the car and the bumpers - we did not get the 280z bumper on any of our Zs. All have the 240z type - my Z is a 1977 260z basically bodies is like a 1977 280z but with 240z bumper, euro tail lights and RHD. Trim is the same as the 280z. The S31 did have different trim (this might be the look of the 240z ie vinyl etc but with 280z like door trim etc). My 260z had carpet not the vinyl and does not have the vented hood - the only vented hoods I have seen have been LHD 280z imports from your part of the world. With the mesh grill I would say it is a S31 (I believe all S31 were L20e ie injected L6 1998cc).

 

So is this a S31 or a GS31 (2+2)?

 

yes those figure I poster were for the L20e six for the S31 model (other model cars that used the L20e got less power - I guess via different cam timing)

 

Regards

Mike L.

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Guest ON3GO

its a 2 seater.. our HLS30 pretty much.

other things i remember...

 

it had the reg ole USDM nissan OHC valve cover.

seats looked like ones our 280Z got, the early 280Z atleast with the little vents on them.

i cant get over how big the piping was on the header, it was HUGH!

tranny was a 5 speed, it was very short geared.

thats really all i remember.

 

i was really looking at all the rust on the floors and frame rails, its gonna need to be completely redone, i mean 100%!

 

one thing ill need to figure out is the dash, its cracked abit and i want it perfect.

but i dunno what to do about it since its rhd and all.

 

mike

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The gearbox will be what we call a 240z/260z B box downunder. The 280z B box has a wider 2 to 3 than the 240z/260z B box. Most Z in this part of the world have the 240z/260z B box only the 280zx had the wider 5 speeds. They are a good gear box to have as they are quite close ratio with only a wide 1st to 2nd. My 260z has one of these.

 

re the cam cover yep most L series have those. The rare ones are the same down here also. ie 2400 o.h.c (on the series I 240z), I believe there were also 2000 o.h.c for the very early L20a (twin 40mm SU carbs not like the 240z 48mm SU). Only the very late L28 83-87 (yep the JDM keep using the L series until the R31 skylines when the RB relaced the L series) had the very chunk NISSAN cam covers.

 

Most of the RHD dash crack. Here in NZ I had my covered/restored. Other than that I am sure I could see if I can find one for you?

 

Regards

Mike

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Guest ON3GO

please let me know if you find a nice uncracked RHD Z dash..

i wouldnt care if its a 240Z style or 280Z style.

i do hope i get this car, only thing thats holding me back i risk of the car being a complete loss as its got alot of rust.

BUT im up for the task.

 

i guess its sorta rare here in the states so that adds to the wow factor.

plus it has been about 3 years since i driven RHD and wow its werid lol..

i was all over the center of BOTH lanes lol.

 

i cant wait!

 

mike

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Guest ON3GO
Buy the car and swap all the parts to a good US shell and then youll have a fairlady.....forget the rust bucket, its the parts that count...

ya i know what ya mean, but its just not the same..

its either this project or the alfa GTV 2000 i was gonna buy.

BOTH need same amount of work but atleast this Z is sorta rare over here in the states and is something some of us USA Z owners really want, well atleast i do.

 

who knows, i have the cash but im not sure if i want the trouble...

 

well ya i do lol

 

mike

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Guest ON3GO

hahha sounds like how i was when i owned my S13 silvia for 3 months..

i could only go to Checkers because of the dual drive threw.. lol

 

mike

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hahha sounds like how i was when i owned my S13 silvia for 3 months..

i could only go to Checkers because of the dual drive threw.. lol

 

mike

 

you have had the coolest cars... you're going to have to tell me about this silvia.

-Oliver

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I have a neat photo of my L20A I will find the link and edit this post to contain it here.

 

We are hoping for a tad more than 200Hp at 9Krpm. We are using the L20A because we already have all the available records in the 3L Normally Aspirated Class we race in at Bonneville.

 

If your car has an N42, head, the engine has been swapped. Chances are it has an L28 in it already. Very common swap. The Fairlady Z's are ALWAYS considerably quicker than a comparable US Spec Version due to weight and gearing differences. An L28 in a Fairlady is a rocket, for sure. You can go to my cardomain site and see our E88 head on an L20A, and I can assure you HEAVY block work was required for vavle clearance!

 

I own three Fairlady Z's, and the photos below are from our 1976 280Z 2+2 Bonneville Racer. You can view the full size images at my Cardomain Site.

735451_136.jpg

 

735451_145.jpg

 

735451_141.jpg

 

735451_142.jpg

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hahha sounds like how i was when i owned my S13 silvia for 3 months..

i could only go to Checkers because of the dual drive threw.. lol

 

mike

 

I usually either Drive Through in reverse and see if they realize it, or let my kid take the food and give them the money and see if they notice.

 

It was a hoot driving through West Virginia in the car! (Banjo Music Interlude) "Hey boyah, where you git that thar car wit the wheel on the wrong side? England er sumpthin?"

 

LOL

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