Why do 240Z Owners So Often Put L28s in their cars?

[gnosez]

Modified car, modified engine. Enhanced suspension and brakes means I can add HP/torque without unbalancing the car. Think race car but usable on the street.

That and the fact my bored and stroked L28 (now 3.2L) NA motor makes 315 HP @ crank. A similar L24 engine making the same or even more HP (can be done w/right head, etc.) would likely have a 16:1 compression ratio and a life of just a few hours.

But the real answer is simple. It makes my 240 go real fast in a very short period of time. That and the sound of those triple 44mm Mikunis opening up as the exhaust gets louder.

But each to his/her own.

[jmortensen]

Cost to speed ratio of a 2.7 stroker vs a 2.8 swap makes the 2.8 a no brainer if what you're looking for is a fast car at a cheap price. If you want a concourse restoration, then a swap is not for you. But if concourse is the idea then the stroker is off the table too, and one might just as well ask why people prefer to spend $50K on a car that will be worth $25K when it is done and still be slower than the one with the 2.8L motor swap with triples or a turbo, etc. If it's not a concourse car, how smart is boring the block all the way out in order to keep the matching numbers engine? It's still a driver, so what happens when the engine gets old???

[kenz240z]

Because I'm a gearhead and I can't leave well enough alone. It all started when I was a teenager and swapped the Rochester 2 bbl carb on a small block Chevy with a Carter AFB 4bbl. I've never been the same since...

I bought my first 240Z about 8 years ago. A non-numbers matching 73 with an automatic tranny. Initially I kept it mostly stock with an L24 under the hood, but longed for a bit more performance and a manual transmission. For 300 bux, I got a '82 280ZX from a salvage yard. The L28 and the 5-speed went into the '73. The R200 diffy went into my V8 Z project, which is also a '73 (see, I can't leave well enough alone!). In my defence, I still have both L24's. And I'm almost finished refreshing a '71 with the numbers matching L24 that I have kept intact.

[Jennys280Z]

Cost to speed ratio of a 2.7 stroker vs a 2.8 swap makes the 2.8 a no brainer if what you're looking for is a fast car at a cheap price. If you want a concourse restoration, then a swap is not for you. But if concourse is the idea then the stroker is off the table too, and one might just as well ask why people prefer to spend $50K on a car that will be worth $25K when it is done and still be slower than the one with the 2.8L motor swap with triples or a turbo, etc. If it's not a concourse car, how smart is boring the block all the way out in order to keep the matching numbers engine? It's still a driver, so what happens when the engine gets old???

If it's a driver, just stroke it and hone it? Regarding power it seems to me that upwards of 300HP should be more than enough for most people needing a speed fix on a <2500lb car. Just how much traction do people intend to lose? But maybe I'm underestimating most people. But based on a lot of Z owners I know, I doubt it.

An L28 in the junkyard is a no-brainer for the budget. And I think that's really the biggest answer here to my question. Conversely, if building out the L24 was the cheaper alternative, it'd be popular.

[SteveJ]

Because my 240Z came as a roller and the original motor from my 280Z was full of cobwebs on the garage floor. Put two and two together and I have an L28 240Z.

I wish I did have the original block to match the engine plate in the bay. It's somewhere in GA, North of Atlanta.

Dave, I looked in my garage. I didn't see it in there.

[steve91tt]

My car's a daily driver. The extra displacement makes the car much more fun to drive. For me, the fun factor far outweighs any small value I may have sacrificed in not having a numbers matching 1973Z.

In the end, most 240Z's are not investment grade cars. Having the original engine is not a big deal in a non-investment grade car. IMO.

[Diseazd]

Also, when you pull your original L24, it should be kept on an engine stand ready to be returned to it's proper place. Both of my L28's have the original motors ready to go back in.

[sblake01]

Why? Aren't your cars, though very nice, somewhat modified in a few other ways like wheels, 'da twin stax', etc.? Do you really have intentions of someday turning either or both of them back to completely stock?

[Bruce Palmer]

The answer as stated several times here is cheap horsepower, but there is another factor involved. Figure the cost to go thru a 2.4 and a 2.8 to be a push, so with the 2.8 you get a finite amount of HP and torque in a LOW stressed package. To duplicate that HP and torque with a 2.4 it'll run at a higher degree of stress to produce the same amount of work. i.e. closer to the ragged edge of destruction.

To make the machine work changes to turbo-ize an engine that'll live, isn't cheap either.

With our crappy gas today, low stress is good.

[madkaw]

I have been a defiant one and have stayed with the L24. I hope that my efforts to properly rebuild and properly tune the L24 would keep with any L28. Of course my decision was also based on the fact that why would I go source a L28 when the L24 is right there. Do I want to swap a motor out to gain 20hp in stock form? If your plan is modifying your engine, the L24 can be an excellent platform. As for me, I plan to modify the L24 with triples, then ITB's, and then turbo charge the ITB's, so it won't be about cubic inches as much as doing it right.

I almost look at it as throwing in a V-8, it's easy HP-no doubt. I guess I rather be able to brag about my modified L24.

[esmit208]

Jenny

To each his own. I personally wouldn't install a V8 conversion. With an L28 having just that much more meat on the cylinder walls they can be bored out to a 3.2 and have good manners in traffic when tuned well. 3.2 litres and 300+ HP is more than enough for these nimble machines. But that is just my Humble opinion. As somene said previously even if it is possible to bore a 2.4 out it's shelf life wouldn't be very long due to the heat it would generate. Very few 240Z owners even care about matching numbers and all that jazz. Most of them would trade numbers for power. If you restore one of these rigs to sell it on you are making a mistake. Even if you get what you paid for the parts you will never recover what it cost in man hours which could well exceed 2000 hours.

[IdahoKidd]

I absolutely agree with esmit about the values. I have a bone stock original (wrong hose clamps on radiator and one braided line missing) 240 that isn't worth what its slightly modified twin is worth, and that car will be worth about 40% of actual investment when it is finished. Nothing kills the value of a Z like installing a v8 in the back yard. To the average guy looking at what they think is period correct, the 2.8 is a direct and accepted replacement. If you don't know the difference, you can't tell the difference. Each of us have made a decision as to how far to modifiy the car and if that mod is reversable. Once you start cutting, fabricating, etc, going back is difficult. If there were only a dozen 240's left on the planet, it would be sacraligious to alter them. There are literally thousands of them out there so it really isn't a big deal.