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HybridZ

A custom 240Z/260Z engine?


Starking

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My family has been one that loved the Z, my grandfather tends to talk about a old Z he use to have. He did a tuning to his that I don't ever hear about online, but since I plan to follow in his footsteps and get myself a older Z. This is what he says "I toke the top half of a 260 motor and the bottom half of a 240". I was wondering, is there any info on this sort of hybrid engine. No matter where I look, I can't find a thing about these motors. The only reason I know he did the tuning is because of Uncle and Mother.

 

So, what does this sort of tuning do to the car anyways. If anyone has any info that would be of great help >.<

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Sounds like he put a 260Z open chamber smog E88 head on a 240Z block. Do a lot of searching on this site and you'll see what the current thinking is regarding the Nissan L-Gata 6 cylinder engine.

Not much really said about L-Gata Engine, but yea. That sounds like it.

I really want to point out the oddest claim. The car ran on a 4 Speed Manual and could hit 160 without a Supercharger or a Turbo. From what he said, he really don't do a whole lot of work to the engine. He just did a few minor tunes. But still, should a L-Gata be able to reach that sort of preformance?

 

EDIT: MJLamberson, if I'm right. I think it was to get the best of two worlds out of the car. At the time, the Z32 was out. So he could have gone with a L28. But the reason why he went with the 240Z/260Z hybrid engine is what gets me. But a guy know knew his stuff about the Z must have had a good reason for doing so.

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Thing really said about L-Gata Engine, but yea. That sounds like it.

I really want to point out the oddest claim. The car ran on a 4 Speed Manual and could hit 160 without a Supercharger or a Turbo. From what he said, he really don't do a whole lot of work to the engine. He just did a few minor tunes. But still, should a L-Gata be able to reach that sort of preformance?

 

No, probably wouldn't be able to do over 125.

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No, probably wouldn't be able to do over 125.

Ok then, I'll have to ask him what he really did. Bored and stroked would have up the power, but I don't think that would even start to get though the 160 barrier. Well, when the time comes. I'll get to see the tuning done for myself. Since I guess its a pretty cheap tuning(From what I guess). <.< I just planned to dump a Turbo or something of that nature on something like that.

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people back in the days used to do all sorts of stuff for performance, i had an uncle back in the early 80's, and he was doing the Z24 block, L18 or L20 head way before most people were doing it with his own custom machining and parts, and this was on GUAM, in the 80's, you pretty much had to make your own parts as there wasn't much going on there in those days. even if it was a 3hr plane ride from japan. im not too sure what people did with Z's on guam back then, from what i remember growing up, i never even saw one on the road. the 1st time i saw a datsun s30 Z was in a junkyard, and even though it was rusted and tore up, i was blown away by its shape, and its long "nissan OHC" chrome valve cover, i thought it was a giant Z engine (i used to race those Z24's big time) and i wanted one since then and finally got one here in the US with 64k original miles and garaged for the past 10+ years, AND it was one of the first 280Z's in arizona, owned by the girlfriend/wife/mistress of the owner of Smith Datsun in Mesa, AZ. how's that for lineage... :)

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what would be the point of combing those two engines?

 

The main difference between the 240Z, 260Z, and 280Z engines is basically bore and stroke. All three engines are 90% the same and can be considered variations on a theme, just like the 283, 302, 327, and 350 Chevy small blocks. Putting a 260Z E88 open chamber head on a 240Z block will, if you're lucky, basically give you a zero horsepower gain. Inreality, it will most likely actually reduce horsepower due to the drop in compression ratio.

 

Not much really said about L-Gata Engine, but yea. That sounds like it.

 

The entire Nissan L6 Forum on this site discussed the engine.

 

Bored and stroked would have up the power, but I don't think that would even start to get though the 160 barrier.

 

With 320hp my 240Z could reach 148mph and might have topped out at 152 but the race track turned left and I had to brake. Without aerodynamic work you would need at least 400hp to get to 160mph in a 240Z.

 

Again, search. All this has been discussed many times over the last 8 years here.

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Ok, I just did a search on "L-Gata". Didn't bring up a whole lot. Isn't the normal compression ratio in a Z Engine close to 185(I could totally be wrong here, I know standard cars don't run that high). I think the top half was more focused on the Carbs then the Chamber Heads.

 

The end goal with the Engine, and from what he wanted to do.

Bored and stroke, turn it into a Short Stroke, after that I pointed out the possibilty of turning the Engine into a Twin Turbo. A long shot at best, but the goal would be a total monster by the time I got out of High School. The plan was really to work on a 260/280Z, because of the Wishbone Suspension. I never really have seen a older Z up close. So my info might not be good for crap.

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Step 1.

Step 2. (after that thread, step back and read the other stickies in the L-series forum)

 

Then, as a bonus, I will reach into my "Bag O' Links" and toss a couple other bones out for you in nor particular order...

http://www.geocities.com/zgarage2001/z.html

http://www.ozdat.com/ozdatonline/enginedesign/

http://www.bandmzcars.com/headinfopage.html

 

There are more where that came from... most of them will be found in one of the first two steps.

 

Read a WHOLE lot, and you will be surprised how much you suddenly know, about how little you know.

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Well it sounds like you have a butt-load of research ahead of you. Regarding the L-series, or any engine for that matter, there is no “magical” special combination of short stroke big bore or vice versa that offers ANY sort special magical mystical performance, real or perceived. Torque comes from displacement, HP comes from said torque AND RPM. The higher in the RPM range the engine makes torque, the more power it will make. Then it is the fine tune that will extract the maximum output from that engine build combination making it stand out from the rest of the cookie cutter builds.

 

With that, always build the engine with as much displacement as your budget can afford. That will be your basis for building tire shredding torque, (A small block Chevy bolts in the car with very little mods and adds only small amount of overall weight considering how much more displacement you gain, i.e. 350 doubles the displacement of the L-28 at approx 150# lbs weight gain with iron heads etc! Aluminum heads and several other weight saving measures can bring a V-8 conversion to less overall weight than the L-28! Now I’m not saying swap in a V-8, but that extra displacement does bring forth quite a bit of fun factor when the loud pedal is mashed.) Then depending on how you intend to drive/use the car, that will dictate how you go about building the upper end, i.e induction, exhaust, cam etc. That will dictate how much HP the engine will produce and how it produces that HP. Add a hair dryer or two and now you have an entirely different monster which can produce torque and HP on par and even more than the naturally aspirated V-8’s.

 

Here are a few threads for you to read regarding making power with the L-series. This should keep you busy for a while…

 

 

 

L-6 internal dimensions..

 

 

The Big BORE stroked L-6

 

 

L-series cylinder heads, big and nasty head work for big power.

 

 

***edit***

Daeron beat me to the first link…

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if the wrong gear was in the transmission he could have thought he was doing 160 on the speedo. for instance...if you were running a 4.11 by chance and had a cog in there for a 3.36 rear end you might be doing 130 but your speedo would say closer to 156. also tire size can throw you off a bit. i have heard of people "back in the day" throwing a 240z head on a 260z or 280z short block but not vice versa.

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My engine is a 'hybrid' using an L28 block and an earlier 240 head that has been ported. This combo provides high compression and the porting along with a race cam, syahl headers and triple 45 DCOE's is supposed to give 249bhp at the wheels. When I finish the car I'll let you know if it really lives up to that lofty claim.

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Good luck in your research, glad you are following your granpa's footsteps. And can we have some more quotes from your granpa, I was enjoying them. Big up to your granpa, once a Z man always a Z man.

 

As for links for your research, besides the excellent ones above, also check this out: http://www.datsunzgarage.com/

Yea, <.< Starting to wonder about his claims. But depending on what might happen. I would look into a L28 or even a V8(If I could find one, the thing I like about the V8 is the LT1. If I'm right, some came with a 6 Speed). The problem with the V8 is I never see a Turbo conversion for it(I know they are out their. But I'm not one on looking too hard). So any heads up on that. I'll most likely go with the 240(I just love the look of the 240 over the 260 and 280. Even though they look close, there are so differences). I really want a sort of sleeper car in a sense. 240Z is an older car most people wouldn't think twice about people fast.

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I have an L26 that has the higher compression 240Z flat-top pistons in it. The rest of the longblock is basically stock except for a light-weight flywheel.

Then it has early 240z SU's and a header/2.5" pipe and hollowed out muffler.

I was able to maintain 135 @6500RPMs fairly easily for a couple miles (checked with gear ratio calculator...Speedometer said 155mph...LOL)

 

If you put any 260Z or 280Z head on a L24 block you need to notch the cylinder walls to clear the valves. The L26 "P30" block is identical to the L24 "P30" except that the L26 block has the valve notches already in the bores for larger intake valves.

 

If driven well you can keep up with most modern cars...

I kept a lead on an 03' corvette once Just because I wsen't shifting all the time..

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as far as the love of the game goes, there really are unlimited options for a motor for your z.

 

personally, i love the idea of a 6 cyl turbo diesel cummins in a 240 as a drag machine (wouldn't much be able to see over the hood, but the sucker'll fit)

 

however, as far as practicality goes (hah), I only see two options for my car: l28et, or ls1.

 

l28et (the turbo l28 motor) is just so damned easy to swap in, and once it's there, for $15 you can get a manual boost controller, and just dial-a-horse.

 

the ls1 is more complicated, and once it's in, it's in, and there aren't a whole hell of a lot easy ways to get more power (this is true between any naturally aspirated motor vs any forced induction motor).

 

Maybe the romantic in me just loves the idea of a cheap power gain. "sorry, girl, all i can afford is this brass piece of valve."

and she loves it so much, she gives me a 200 horsepower gain.

 

LOVE IT!

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If you put any 260Z or 280Z head on a L24 block you need to notch the cylinder walls to clear the valves..

 

I think what you meant to say is notch the piston tops to clear the valves, yes? I believe the process is called having the pistons 'fly cut'.

 

I have never heard of notching cylinder walls.

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I think what you meant to say is notch the piston tops to clear the valves, yes? I believe the process is called having the pistons 'fly cut'.

 

I have never heard of notching cylinder walls.

I mean what I said and I said what I mean. :-D

Forget the nicks on the pistons (that was an accident...)

look at the bores. Stock L26 with L24 pistons

b89081353.jpg

The reason those two pistons are polished and the other isn't is a little experiment that I'm doing to see if carbon builds up less on polished pistons...

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