Dark side?

[Z24O]

After peoples opinions on the pros and cons of these 2 engine swaps

I have a Boss 302 in my 240Z,fantastic to drive,very torquey in such a light car....however my other Z has an RB30 turbo in it and is significantly faster but not as much fun to drive off boost(nowhere near as much torque)

 

Here is my quandry...

I have a turbo 302 ready to go in the Z however an acquaintance of of mine is singing the praises of an LS6 (hence the dark side reference) Z conversion with a better flowing intake(there is even a carby version available that integrates with the LS6 electronic ignition without the distributor)

I am concerned at keeping the weight down and so the 302 has aluminium heads and EFI intake...i believe it should weigh in dressed at 425lbs or thereabouts

Now the LS6 auto dressed weight is around 460lbs i believe,not a huge difference

 

I am hoping for 450-500hp at the wheels,this will be approaching the limits of a 302 windsor block but should be achievable with a turbo(although i have a mexican block to use as well),the LS6 standard pumps out 385 hp@6000rpm and 385ftlbs of torque at 4800rpm

 

It is obvious that my driving style favours torque over HP,but....is the LS6 likely to be too much torque for the little Z,would i be satisfied with the torque of the 302 cubes with the extra kick from boost,would it make a better daily driver?

 

The sensation of driving my 2 Z's at the moment I can best describe as a steadily increasing push back in the seat feeling from the NA 302 vs an elastic band feeling from the turbo,slowly pushing you back and then snapping your head back as it comes on boost(it's quite a rush but with normal sedate driving you don't get it as you are changing gears before the boost comes on)

 

Opinions appreciated,room for lots of 2c in this thread.

[blueovalz]

It sounds like the turbo engine could use some work or something. The boost should come in smoother than you've described.

 

The 302 block can be a weak spot, but the "magic" block splitting horsepower number has a lot to do with overspinning the thing as it does with brute torque. With the turbo 302, I fiqure the weight will come in pretty close to the LS6 (turbo, plumbing, etc), but even with a small amount of boost (8-10 lbs), you'll have more torque out of it than the LS6. But you'll have more work to do as well, so I guess it all boils down to more money and work = more power (which everybody on this site has already figured out).

[WizardBlack]

It sounds like the turbo engine could use some work or something. The boost should come in smoother than you've described.

 

The 302 block can be a weak spot, but the "magic" block splitting horsepower number has a lot to do with overspinning the thing as it does with brute torque. With the turbo 302, I fiqure the weight will come in pretty close to the LS6 (turbo, plumbing, etc), but even with a small amount of boost (8-10 lbs), you'll have more torque out of it than the LS6. But you'll have more work to do as well, so I guess it all boils down to more money and work = more power (which everybody on this site has already figured out).

 

QFT

 

Just to add, you sound like you have a slightly mismatched turbo sizing issue, but you have locals that aught to be able to tell you on that one. I don't think you will find a 5.0 liter turbo engine (properly set up) quite so laggy unless you really build it for high-rpm power (which the block won't like). I think it all comes down to heads, however. If you have a nice head setup ready to go in with that 302; don't worry about switching. If, however, you don't, then I'd say the LSx would be a reasonable alternative.

[Gollum]

What 302 block do you have? Is it the earlier 302, or the later 302? They removed a bit of weight from the blocks at one point, in the late 70's or early 80's I think, and the ones made after the change are the ones known to crack.

 

The boss 302 has proven to be able to widthstand much more than the run of the mill "5.0 HO" blocks tend to take.

 

I'd say go with the turbo 302. But that's just me. I can't bad mouth the LS6, as it's a great engine. It's just prefference.

[WizardBlack]

What 302 block do you have? Is it the earlier 302, or the later 302? They removed a bit of weight from the blocks at one point, in the late 70's or early 80's I think, and the ones made after the change are the ones known to crack.

 

The boss 302 has proven to be able to widthstand much more than the run of the mill "5.0 HO" blocks tend to take.

 

I'd say go with the turbo 302. But that's just me. I can't bad mouth the LS6, as it's a great engine. It's just prefference.

 

He said he has a Mexican block. Those're the ones with a bit more beef and more nickel in the metal (IIRC). From his post, I don't think he was gonna risk the Boss with boost, etc.

[lilredZ]

I'm probably going to get slammed but:

 

All else being equal (which it never is) I'd pick the Chevy simply because it's cheaper to build and easier to get parts for. Just pick up a Summit catalog and look for a good set of heads...

 

I have built both motors and the Chevy is much easier to build cheaply and quickly and (perhaps) more reliably.

 

That said, the reason my car has a Ford motor is that (back when this car was built) it was the only option for going low and back in the engine compartment. Engine weight (CG) has a huge impact on handling.

 

I thought the extra 60 lbs from the recently added Dart block (and forged internals) would not be significant but it did change the handling...its only a tad bit harder to steer going slow but it dives in (oversteer) to turns and has deminished what use to be fantastic handling. It still handles good (I'd say a modern Civic or TL) but the change is noticable and if I were all about handling (I'm more about who wins at the red light) I would not have added the weight. PS with my new (Brodix) heads, cam and lifters I should be running about 575 Hp with plenty of torque (Naturally Aspirated)...