v8 conversion or GN v6

[Guest Anonymous]

i am very interested in putting a v8 but i heard that Grand National engines put out just as much power. can any one tell me how difficult each is to install and the differences. thank you very much.

[pparaska]

I'm sure Scottie will chime in - he's had both a V8 Z and now has a GNZ. The GNZ is not documented, but then Scottie can give pointers. Someday I hope to get a ride in his car - with that V6 mounted so far back it's got to handle nice! 400+ hp (I can't remember what he's got it running) in a Z is quick, no matter how it's done!

[John Scott]

zlover, Welcome to the Hybrid site.

Also note there are no kits or manuals for the GNV6 swap, but some fabrication skills and Scottie's good advice will get you rolling. BTW I moved your fender flare question to the paint and body forum.

JS

[Scottie-GNZ]

Zlover, welcome to the Hybrid site.

 

I have done 2 V-8s, a Scarab and a JTR, and my current 71 has the GN. Before you even get into any discussion on which one and how, you need to ask yourself a couple of questions:

1. Do you want a turbo?

2. Do you want an automatic?

3. Do you have mechanical and some fabrication skills? If not, can you afford to pay for help?

 

If you answer No to 1 and/or 2, then the answer is a V-8. No 3 applies to either swap but more so to the GN swap. There is no kit for the GN swap!!! You will have to make a bracket to bolt up the motor mounts to the frame. That is the hard part (see my comment below). The trans crossmember is a simple affair that bolts up to the floor and I am sure you can use the JTR unit. If not, I have the specs for mine that you can duplicate. You will need to muck with the GN harness, more to eliminate 50+% of it or you can buy a custom harness made for swapping the GN drivetrain into other cars. Beyond that, the rest is just normal swap issues like driveshaft, radiator/fan, water/oil senders/guages, shifter, driveshaft and of course I/C. I am working with a local friend to do one and he is going to use the stock GN I/C in the stock location which greatly reduces the complexity of the plumbing. Whatever we come up with for mount brackets, etc, I will properly document it.

 

As for the V-8 swap, I would recommend looking at JTR first and last How difficult that swap is depends on your mechanical skills. Some folks use the JTR specs to make their own brackets, but I personally do not think it is worth the hassle and risk of making mistakes.

 

As for which I prefer? I had the same decision and having already done a V-8, it would have taken an LS1 for me to do another one. Now that I have done the GN, There is no looking back. The initial outlay for the drivetrain COULD be higher, but having seen the cost of some of these crate engines and T-56 trans, I am beginning to think not. If you are into autocrossing, road racing or the twisties, the V-8/5-spd combo will probably suit you better. If you want a smooth, economical daily driver that has 10-sec potential with minimal upgrades, then you want the GN. The hottest crate motor is hard pressed to match the HP/torque of a GN with a turbo upgrade in the hands of someone who knows how to tune it. Based on my ET/MPH/Weight, I am close to 400hp AT THE WHEELS and expect to break into the 10s before the year is out The only major upgrade I have is a $600 turbo (minus selling the old). A lot of folks think turbos is black magic (BLKMGK ) and if you are new to turbos and decide to go the GN route, you have a lot to learn, and some habits to break or you will break something.

 

I am rambling, so in closing, be assured that whatever decision you make, you have a host of folks who have been there and done that ready to help you.

 

------------------

Scottie

71 240GN-Z

http://www.mindspring.com/~vscott911/gnz.html

[BLKMGK]

Hey now - I LIKE turbos I've had a pair on a Ford 302, now have a blower on that same car, and just bought a twin turbo RX7! (talk about fun!) Friends of mine drive GNs that fly - lot's of parts out there for them too. Heck, I even considered a turbo kit for my Miata but have decided to sell it and bought the RX.

 

So, why didn't I decide to do a turbo L6 or GN? I wanted something straightforward and documented. Yeah, I can blow money to have stuff done but I'm hoping to actually get my hands dirty on this project. For me, the V8 made sense and I'll have some help from Mike Kelly if I get stuck. For ME an auto just wouldn't cut it this time around - to each his own. A GN motor would flat out be awesome in a Z and if that's the path someone takes thenm more power to them. It's much easier top make big power numbers with a force fed engine and I'll be very surprised if in 2 years my Z isn't force fed in some manner but baby steps come first....

 

P.S. Had I driven a turbo L6 earlier I might have considered that swap more seriously too. I know V8s though and the T56 is something I really wanted. Silly huh?

[Scottie-GNZ]

BLKMGK,

 

sorry, did not mean to imply you did not like turbos. On the contrary, anyone who had a twin-turbo V-8 and now a 3rd-gen RX-7 must like to whistle .

 

"....black magic (BLKMGK)" was supposed to be a play on words. Not so clever I guess.

 

Scottie

[Andrew Bayley]

Awww Damnit!!!

Now you guys got me thinking about a twin turbo small block again.

 

...thanks a lot!

 

(Desiring best of both worlds)

 

-Andy

[BLKMGK]

No problem Scottie, just making sure folks know I like forced induction is all and I did catch the play on words My current RX doesn't whistle though which is a shame - the Greddy BOV and elbow may fix that this weekend though. Even the V8 didn't make much more than a whoosh - used to really mess with people's heads with that one! Darn RX is pulling funds from my Z too (sigh).

 

As for a twin turbo SBC... LOT'S of power! But do you really need it? Might it simply rip the Z apart? There's lot's of complexity going on there. Maybe a single turbo would work well but the crossover piping would be a PITA. I note that LOT'S of Mustang racers are switching to turbos and the big ATI blowers. Turbos are really sweet but you'll have heat, plumbing, and all sorts of other stuff to contend with. Do yourself a favor and consider the simplicity of an ATI blower