To swap or to mod, that is the question...

[Guest Anonymous]

Well, I've been doing some reading and some posting, and am starting to understand Z's a bit better.

 

I am basically debating between doing a V8 or V6 swap, or building up a Z-motor, or something more compatible with Z-parts (like a ZX-turbo swap or something like that).

 

For the latter, I was considering swapping in a later, FI motor, having some headwork done and boring it out to 3.1L. I was going to throw on the Jim Cook supercharger and run a good exhaust.

 

Would this be reliable? Would this get into the 250hp neighborhood?

 

If not, I am leaning to a V6 swap. Simply because, the reason I am looking at Z's instead of doing another musclecar is because I wanted a car that could perform and still get mileage in the low-mid 20's, and was tired of a driving gas-guzzling streetboats ('68 Charger, '70 Coronet).

 

Am I just misguided?

[DavyZ]

Are you misguided? Well, sort of. Here's my take on it:

 

You want some power and mileage? Well, the 3.1L L6 is not the hot ticket for mileage. 250hp is more than doable with the supercharger, but you should not look there for what you really want. Let me explain.

 

A stock TPI or TBI swap will give you three things: 1) reliability--hey it's going to start, parts are relatively cheap, and maintenance you can do yourself. 2) power--torque will be great and give you what you crave deep in your soul. 3) Mileage--you couple the FI with a good overdrive tranny like a T56 and you are near 20 or above on the freeway.

 

'Nuff said.

 

Davy

[Drax240z]

OK, now for the other side.

 

A high compression naturally aspirated L28 can get you to your goals. 220ish flywheel horsepower, and 20+mpg in town, 25+ on the highway. A little harder to do using stock EFI, but it can still be done.

 

However, if you are like most people, even 250flywheel hp will feel slow eventually, and you'll want more. As far as I am concerned you aren't going to get a lot more hp out of a N/A L6 withou putting in a TON of money. Thats when you should start considering a V8, L6Turbo, etc swap.

 

Can you be sure that 250 is going to be enough? If you are sure, then go for the NA L6. If you aren't sure, then every other concievable option has been discussed on this board at one time or another. Start reading!

[pparaska]

I don't think that just because you put a V8 in a car it makes it a muscle car. You can do a slightly warmed over 350 Chevy in the Z and get 12 second 1/4 miles with grandma like around town driveability. And that's because it's so much ligher than a real "muscle car", which typically is in the mid to high 3000 pounds range, like 3500-2600 for an old Camaro.

[Guest Anonymous]

You kind of have to also examine how much money your talking. I'm assuming the Jim Cook blower is going to set you back 2-2.5k just for the blower, the engine work to rebuild or take out to 3.1l plus the blower starts adding to quite a lot of money at least it would seem. If you thinking of a blower like that, it would seem way cheaper to get a L6 turbo motor freshen it up and dump it in, , put in a intercooler and pump up the boost a bit and have a fast ride for less.

I like the V8 in mine and I could have been happy with a stout V6 as well (A GN Buick Turbo motor would be a great option if you can find one cheap enough). Depends on what you like really and what kind of deals you can find IMHO.

 

Regards,

 

Lone

[Guest Anonymous]

why not just build a n/a l-28 with some decent pistons arp bolts and just run a port NOS settup.i had a 3.0 liter with a good sized cam and crappy injection and EVERY other import in town was scared to death of me.a really well done NOS settup should cost in the neighborhood of around 1500 or so with ignition retard box, bottle heater ect.

[Scottie-GNZ]

Ashe,

 

if you are contemplating an engine swap, you are more than welcome to come look mine over. Drop me an email and lets get together this weekend.

[BLKMGK]

Here's my take on this... A turbo motor is probably going to get you where you want to be easiest. I don't know much about the turbo L6 but it sounds like a straightforward swap. You can get 250 out of it I'm sure with some work and some help. However, IMO, 250 will be "fun" for all of about 3 months. At that point some warmed over Honda, pimped out Mustang, or stock Z28 will clean your clock and you'll be upsewt. 250HP these days isn't much, stock V6 motors in family cars make nearly that much in some cases!

 

You'll want more power and at some point your mileage will go bye bye and you'll begin pouring money into it. If you want good driveability, decent MPG, and the ability to turn the wisck up without blowing a zillion I suggest you consider the Buick GN drivetrain for sale in the Buick forum.

 

Scottie is local(ish) to you and has done this - a serious advantage! he knows the electronics and would be able to advise you. Scottie gets decent MPG with his car when it's just cruising but lays down the hurt on most everything at the track. Yuo don't need to go as fast as he is but you'd be able to do it if the bug hit. Yeah, you'd probably run an automatic and you might not like that but it would FLY. You could do a stick too but I'm not sure the results would make you happy.

 

A mild V8 works too but mileage might not thrill you and when the wick is turned up it'll take more "hard parts" than the GN drivetrain. Mileage will suffer then too. The GN motor comes with EFI, mild V8 will probably be carbed. In Florida that's probably not that bad but in colder climates carbs are a PITA.

 

My .05

[Drax240z]

Actually the milage with any turbo motor COULD be good if you can keep your foot out of it. An L28 turbo engine out of boost should use around as much fuel as a NA L28 would. (a bit more due to lower compression ratio) Even the compression ratio on most stock L series was pretty low, so were you to run 8.0:1 you'd be right in the ballpark. (unfortuantely the L28T is a ghastly 7.3:1)

 

I really don't think supercharging an L28 is your best option from a hp per $$ standpoint, likely your worst. Turbo L28 is probably next, then GN, then V8. If you just want lots of GO with relatively little dough, the V8 is the choice for you.

[Scottie-GNZ]

Ashe,

 

I would be more than happy to help you understand the pros/cons of all your options having done 2 V-8s (Scarab and JTR), a triple-Mikuni 2.8L, an L28T and the GN.

[Guest Anonymous]

Ok, so I did have my head on backwards. The V8 swap concerns me because I hear differring opinions on driveline buildups. Some feel that the R200 rear and axles can only handle a mild V8 (250-300hp, similar torqure numbers), while others claim it can live fine behind a 400+ hp stroker motor. Just as example, I notice Scotty is going to be swapping in a complete IRS rear from a '84 Corvette. This is something I don't want to do.

 

Myself, I'd like to do an R200 swap with a Quaife differential, and so I'd like to build a motor that won't kill that. To expand upon this point, I'd like to be able to beat on it a bit too. Arizona Z-car mentioned the point that some people get engines where the rear will live so long as thy are gentle and don't hammer the throttle. I noticed Arizona Z is not that well liked, but I feel his point is valid. Why swap the engine if you can't get on the power?

 

It also seemed to me that modifying a L28 (swapping a Turbo motor) is much simpler affair than a V8 or V6. I also understand that beyond a Datsun engine, a 350SBC is probably the simplest, and other engines beyond that require a bit more custom fabriacation and engineering.

 

I'm just doing research now anyways. I don't even have a 240 yet (which is the model I hope to use, for smog concerns - FL is a pretty lenient state, but I will probably be moving back to NY in a few years and that state isn't).

 

I'm trying to get near the performance level of a Corvette, or a mildly worked over ponycar. I had thought 250hp would be enough to get me there and not be too taxing on the driveline. Seems I am wrong in my assumptions, which is ok, as I said - I am new to Z-cars.

[Drax240z]

I wouldn't say your assumptions are necessarily wrong. A friend of mine could take mustang GT's all day long in his L28 260z. No mods other than a 75 engine with early SU's. Now its my car, but I haven't been pushing it since its my only means of transport at the moment. No not corvette territory, but it doesn't take a huge amount of power to compete with such a light car.

 

Your 250hp figure is probably a good one for an estimate to compete with those cars in a 240z.

 

A few things to budget for and consider are chassis stiffening, brakes and suspension. You don't want to go too wild with the engine without upgrading those as well.

 

Don't be fooled by thinking an L28 turbo will be a lot easier than swapping in a V8. It really isn't. True you don't have to make motor or tranny mounts, but you still need to do things like swap on a bigger clutch/flywheel, put up some heat shielding, and definately figuring out all that wiring could be a pain! The V8 being carb'ed and well documented (better than the L28Turbo most likely) is really a lot simpler to do a basic install. Plus you can buy nearly everything made for you allready. (motor mounts, headers, etc)

 

And on a final note, I don't see how anyone could break a R200 with 250hp. (unless it was with about 500ft-lbs of torque too) U-joints MAY go, but there are pretty easily available CV joint swaps available. Guys here have put upwards of 500ft-lbs of torque through a R200 with CV joints, and they've raced them... with slicks. Its a damn good rear end.

 

Scottie had other reasons to change to a vette rear than strength. (he was one of the ones with 500ft-lbs, slicks, racing his R200) Gear ratios, weight, traction, limited slip, big rear brakes should all be considered when looking at the reasons for swapping to the vette.

 

[ August 02, 2001: Message edited by: Drax240z ]

[DavyZ]

Ashe, do you have a copy of the JTR manual? That offers some good insight and improvements for any Z. Understand that Scottie is a serious drag racer. I can tell that is not what you want to do--so live with an R200 datsun rear end--no big deal. Get the JTR book and then make a decision about what the car can handle and what you want out of it. I'm getting the impression that you are thinking the car is going to need a lot more work done to it than is probably necessary for what you want out of it. Just a thought.

 

Davy

[pparaska]

Ashe, I'd also add that a Quaiffe is a huge chunk of change for someone not going road racing. Alot of people do just fine on the street with V8 and other high powered Zs with just plain old open R200s. In fact - that beautiful blue with white stripe customized Z on the main page of this site (Terry Oxandale's) has an open diff, last I heard.

 

If strapped for cash, I'd try an open R200 first.

[Jeff]

Ashe, Not sure if your ready to buy or not, but I spoke with a guy in Lady Lake on Sunday whos got a 71 240 for sale. Claims it's a very clean car with no rust on the floors, frames, rockers or quarters. He indicated the hatch & doors were beginning to bubble. He also has a boatload of parts from a 72 that go with the deal. He's asking $1,500. The 71 has the motor and tranny out of it, he was going to do a V8 swap!! Let me know if your interested and I can email you his contact information. I want the car but can't swing the money at the moment.

[Guest Anonymous]

The R200 is up to the task, not a problem really. The U-joint halfshalves don't like (opinion warning!) extreme angles and with a V8 in the car, its easy to reach those angles because of the added torque. Bad angle + mucho torque = broken U-joints.

 

Theres a few deals going right now with CV adapters to use Constant Velocity joints in the rear, with these you wouldn't probably ever have a problem with the horsepower level your talking about. (Matter of fact the U joints probably wouldn't be a problem at that horsepower level either.)

 

I believe one of our members who seems to be recognized as the only one to break a Mustache bar , runs U-joints and races everything on the road.

 

As far as Scottie changing to a Vette rear end, thats out of a gear issue (needs numerically lower than Nissans available gear ratio's).

 

There may be some reasons people may not want a V8 or V6 in they're car, but it shouldn't be worrying about if the R200 can take it. It can.

 

Regards,

 

Lone

[Lone Star 1]

Hey Ashe

I have an LS1 with the 4L60E auto in my Z with a 3.36 diff. I'm getting 20 MPG in town and 26 MPG hiway. This motor is making 289 RWHP and somtimes I still wish for a little more. This motor and automatic can be completely docile and a great driver, or just hit the gas and say goodbye! My point being a nice little LT1 or LS1 with the tranny of your choice will make your Z your most favorite ride. The new newer EFI motors with overdrive trannies are very relieable and fuel efficient.

[BLKMGK]

I'll simply echo - R200 is NOT a problem. It's about the same diameter as the 'vette ring as a matter of fact. Scottie is swapping because he needs low gears - like a 3.07 (!) in order to keep from hitting OVERDRIVE on the track. He's in third right now before the 1/8th mile mark. He's broken an R200 part or two but not many and he's putting out BIG power. Skip the Quaife too - too much money. Go see Scottie and chat, he'll set you straight and his house is really pretty!

[Z-Gad]

Hey Ashe,

Definately go see Scottie if you are serious about getting into the world of Z's. If you aren't serious, you will be when you leave!!

Anyway, spending an evening with Scottie before I started my project was probably the best thing I could have done. I was unfamiliar with the workings and theory of turbocharging and he was patient enough to go through it with me to help me understand the upsides and downsides of a turbo. He also knows a few of people as far as having work done (mandrel bending, downpipes, etc.) as well as other hybrid Z owners in the area. Definately take him up on his offer!!

[Guest empracing]

man you guys must have a differant open r200 over there cos i smoked 3 of em in my z with about 200 hp but then i gave it HEAPS they go ok with carefull treatment if you have the origanl 5 speed in there youre asking for trouble