Advantages of the L28?

[Dirk Diggler]

I know that alot of people swap the L28 into 240s and 260s. I have a 240 with the stock L24 in it, just wondering what advantages and disadvantages come with this swap. As far as I understand, the only big differences are the displacement and fuel injection, with the option of the electronic turbo. The L28 has about the same horsepower (if not less) as the L24 and L26, so what are the big reasons that people make the swap?

[datsunaholic]

The HP lack is due to how HP was calculated, gross HP vs net HP, etc. Plus, the L28s had to account for emissions equipment.

 

Put a properly tuned but otherwise similar carb setup on both the L24 and the L28, the L28 will make more torque and HP.

 

One main reason for doing the swap is that L28 blocks are far more common than L24s and L26s, being the L28 was produced from 1975-1984 model years whereas the L26 was a one-year engine. The L24 was produced for 1970-73 as well as a detuned EFI version 1977-83 for the 810/Maxima, but using the later L24e is no improvement over the original, higher-compression L24.

[Skib]

more displacement, bigger more, easier to find, and can come factory turbo.

 

 

 

drop in some flat tops with a shaved P90 or an E31 head and you got a burly L28

 

also the block to build 3.1 strokers with, bore to 89mm, use 9mm L24 rods and a diesel L28 crank

[Dirk Diggler]

I see. So doing just a straight swap with no tuning or machine work isn't worth it?

[datzenmike]

Comparing the 240/260 hp to the later 280z/zx is like comparing apples to oranges. They were measured differently. If the 240 hp was rated at 150, the rear wheel hp would be about 125 with drive train losses removed. Now you can compare this, to the 280z or zx as apples to apples.

 

Another advantage of a larger displacement motor is that when an equal upgrade is added like the same larger valves, intake, exhaust system (whatever) you will always get more out of it on the larger motor.

[datsunaholic]

It may be worth it if you prefer EFI to carbs. Some folks do. I've never had any luck with Nissan EFI, but that's just my experience. Lots of people find it reliable, and when my 280Z ran it ran great. Problem was it didn't run long before something else went bad. Some folks find tuning carbs hard, and dual carbs impossible. Then you have the smog-saddled flattop carbs.

 

L24 Advantages:

 

Less smog equipment (70-72), though you can convert the '73 to the earlier type.

 

Slightly higher stock redline, though of little use in street engines.

 

They're original to the 240Z.

 

L28 advantages:

 

More torque (especially at the bottom of the RPM range).

Stock have EFI (which is an advantage to some)

 

 

 

If you just plop a L28 in place of a L24, but use the L24 carb setup, what you'd get is an engine with a slightly better low-end torque but the carbs would be slightly undersized when nearing redline. Thing is, the L24's higher redline and the L28s higher displacement kind of cancel each other out as far as flow goes, and the L28 will make more HP at a given RPM than the L24, all else being equal. It's just at the top the carbs MIGHT strangle it, though the difference isn't that much. But the L24 and L28 aren't equal in compression ratio so there's where the stock L28 has its greatest disadvantage. That's correctable. The (slightly) lower redline of the L28 can be offset by gearing, with the superior torque able to tolerate shorter final drive ratios or better overdrives.

 

 

I wouldn't even consider the swap unless the L24 was beyond economical repair and you didn't care about "keeping it stock". Even then, I'd use the L28 longblock with the L24 carbs. If you absolutely had your heart set on EFI, that's another story.

[Dirk Diggler]

EFI= HELL NO!

 

I was just curious as to why people did it. I have the original L24 in my car (1970 240), it runs like a champ, I love it. Carb tuning is cake to me, I learned how to tune a carb on a Quadrajet 4 barrel on my small block chevy, if you have ever worked on a Quadrajet, you know they are damn near impossible to dial in.

 

Thanks for all the info guys, I appreciate it.

[Z-train]

EFI= HELL NO!

 

I was just curious as to why people did it. I have the original L24 in my car (1970 240), it runs like a champ, I love it. Carb tuning is cake to me, I learned how to tune a carb on a Quadrajet 4 barrel on my small block chevy, if you have ever worked on a Quadrajet, you know they are damn near impossible to dial in.

 

Thanks for all the info guys, I appreciate it.

 

If you take HP out of the equation,EFI is superior to carbs in every measurable way.And as far as Q-jets go,they are one of the best and EASILY tuneable carbs ever made.

[Skib]

kinda makin more out than here is in L28/L24 difference,

 

on the outside there all the same, I can swap Z motors in about 4 hours and have it running and driving.

its simple.

 

 

 

L28 has more potential for modding and more torque.

the L24 is the really the same as having an L16 (for you L4 folks)

ya it works fine and you can increase the power but your still better off starting with an L28

 

 

 

you dont have to keep the EFI on the L28 if you dont want it, the intakes, heads, ect are all interchangeable

[Dirk Diggler]

As far a quadrajets being the best carb, I agree. However do a search on Google, you will find people hate them and most people regard them as pieces of shit because they are so hard to get tuned right. Quit being a debby downer on all the threads.

[240ADAM]

If you do go L28 get a F54 block for a 81-83 280ZX. They come stock with flat tops, that block with the E31 in your 70 will make a nice peppy motor. No machine work required, just bolt it all together.

[Z-train]

Quit being a debby downer on all the threads.

Then stop posting bullshit.And i didn't say they were the best,I said they were one of the best.Situation dependant.

[Dirk Diggler]

If you don't like it, don't read it. Not everyone knows everything about everything like you seem to.

[Skib]

If you don't like it, don't read it. Not everyone knows everything about everything like you seem to.

 

 

im gonna stop you right there. i will not have a bitch fight breaking out.

[Z-train]

im gonna stop you right there. i will not have a bitch fight breaking out.

Who you call'n a bitch...you slut you.....

[Skib]

Who you call'n a bitch...you slut you.....

 

Im not a slut I just like sex

[Z-train]

Im not a slut I just like sex

!!!?????

[I'm BLUE]

!!!?????

 

CaddyHack Sent his christmas cards out early this year ??? ollz :lol:

 

Long story short man ,,, If you have an L28 that is in good condition ,,, drop the sucker in ,,, you will not be disappointed ! ( high or lower compression ) I have a lower compression L28 in my yellow z car ,,, drastic improvement ,,, but if you are going to be spending a lot of money , look at ALL options ;)

[datzenmike]

!!!?????

 

That's not rishathra! :o

[SHADY280]

if you have round top su carbs, you can use them and they can make a really large amount of power. almost comprable to triples. the 2.4 can be made to be a monster engine with its short throw. imsa was close to 300hp with race gas. but you still cannot recover torque. thats where that extra engine size and crank throw make all the difference. you can have a low hp engine with lots of torque and spank a higher hp car. plus more torque is fun to drive, you dont gotta wind it up on the street and call attention.

[Master-O-Turbonics]

If you take HP out of the equation,EFI is superior to carbs in every measurable way.And as far as Q-jets go,they are one of the best and EASILY tuneable carbs ever made.

 

Stock Datsun Bosch EFI works fine for a stock engine, but the car will not run well with any type of aftermarket camshaft. Then you have to move to Megasquirt or a Z31 EFI which are both a good bit of work.

 

Early 240Z SU's are a common and good setup for a stock to mildly cammed L28.

My L26 had a header to 2.5" mandrel bent straight exhaust with hollowed out turbo muffler, L24 flat top pistons(9.2:1 compression with open E88 head), and early SU carburetors. Ran awesome.

[Z-train]

Stock Datsun Bosch EFI works fine for a stock engine, but the car will not run well with any type of aftermarket camshaft. Then you have to move to Megasquirt or a Z31 EFI which are both a good bit of work.

 

Early 240Z SU's are a common and good setup for a stock to mildly cammed L28.

My L26 had a header to 2.5" mandrel bent straight exhaust with hollowed out turbo muffler, L24 flat top pistons(9.2:1 compression with open E88 head), and early SU carburetors. Ran awesome.

You changed the equation.My original post still stands.