: Unique engine swap, need help deciding which N*

12-18-08, 10:14 PM
Yes, I did a search already.

I am doing a unique engine swap. I am stuffing a V8 into a 2nd generation aka Mk2 Toyota MR2. This car is designed for a transverse FWD drivetrain.

If you are wondering why I do not use something with better aftermarket support, like a Chevy LS series, its simply a matter of packaging. The LS and most small blocks are around 27-28 inches long (as measured from the transmission bellhousing face on the back of the motor to the front of the crank pulley). The N* is 23 inches long. I am using one of the shortest FWD manual transaxles made, that have the strength to hold up to a V8, namly, the GM F40 out of the pontiac G6. The Fiero guys use N*'s with the F40 quite often. They bolt up without an adaptor.

The space i have to work with requires cutting the subframe of the car even with the N* + F40, but it requires a whole lot less cutting than if I were to use an LS or other small block, as they are 4-5 inches longer and need a 1" adaptor plate in addition. An N*+F40 only requires notching of the frames about 1/2 inch on each side. An LS1 + F40 + Adaptor would pretty much require cutting all the way through the subframe and break out into the wheel arches.

I have been researching what year of N* to buy. As you can imagine, I can use pretty much any of the N* made for transverse application.
I have discovered from your forum and other places, that the 2000+ N* are have many mechanical upgrades. However, I have also found that the COP ignition causes a problem when running a stand-alone ECM (I gotta run the budget versions). There is a Fiero guy that shows how to hack a GM ECM and make it work on the N*, but it requires the pre 2000 version of the N* ignition.

I have narrowed down my choices to the 95-99 N* and the 2000 - 2003 N*. I can get either version for roughly the same price with roughly the same mileage.

I should add, that after the car is running/driving, I want to look into boost via a single turbo. MR2 guys that work on thier own cars usually are very familiar with turbo systems, and I am no exception.

I would prefer to buy a 2000+ Northstar but I wanted to know if the 99/earlier ignition system can be retrofitted to the 2000 N*, as in just bolting it on ?

I don't know what sensors are involved, and I don't know if there is some mechanical drive on the earlier motors (distributor).

How does the plastic manifold hold up to boost? Is melting a problem?
I found that the 94-99 engines can be retrofitted with the early aluminum manifolds. Is this true for the 2000 - 2003 ?

Thank you in advance. If you are interested, I have a build thread on another forum, and you don't even need to register to view it.

12-18-08, 10:27 PM
About all I can help you with is that no Northstar uses a distributor.

12-18-08, 10:30 PM
!!! WAY out of my realm, but I DO know that the changeover from the 4-coil pack to the 8 individual (2 cassette) COP system also changed the spacing and number of cuts in the crankshaft reluctor wheel, so NO, the 2 ignition systems are not compatible. The 2-part and single intake manifolds will not interchange, either.

I thought a MisteR2 was a mid-engine design. Oh, well......you have a daunting task ahead.......

12-19-08, 03:19 AM
!!! WAY out of my realm, but I DO know that the changeover from the 4-coil pack to the 8 individual (2 cassette) COP system also changed the spacing and number of cuts in the crankshaft reluctor wheel, so NO, the 2 ignition systems are not compatible. The 2-part and single intake manifolds will not interchange, either.

I thought a MisteR2 was a mid-engine design. Oh, well......you have a daunting task ahead.......

Yes, all years of MR2 are mid-engine. Its just like the Fiero--transverse aka east/west as opposed to longitudinal (north-south).

Thanks for the info on the coils/ignition, that is the kind of info I wanted.

Please explain the intake manifold situation more-- I only know the following (and I am not sure I have it right)

93-94 manifold is aluminum and fits 93-99 Northstars
95+manifolds are plastic
2000+ manifolds are plastic and the 93-94 alum manifold does not fit 2000+ engines?

What is the deal with 2 part and single part?

12-19-08, 08:45 AM

Welcome, I wish you luck, I watched the fella who was creating the 'ToyStar' years back but eventually gave up, glad to see someone moving forward on this idea again...

As per your questions, the plastic manifold has an over pressure valve on the opposite end from the throttle body that will vent to atmo durring an overpressurization event (i.e. backfire). This was done to prevent the hard plastic intake from exploding.

For running bosst you may want to talk to Mark99STS on this board. Afterall he's the only known person to successfully turbo his car and it required $$$ and alot of modification to all systems, least of which the intake/PCV system. You should be familiar from working on N/A vs FI engines that ANY N/A engine will require modification to make it Turbo friendly. There are many sites out there that explain what valves need to be 1-way vs 2-way, how to inspect more cafefullly for vaccuum leaks that won't 'harm' a N/A engine but under boost could pop hoses, damage lines, etc. These sites may simply not exist for the N* specifically but there's no difference in reality.

Also, before you start you should consider your 'build plan.' When you say you're going to run a stand-alone, are we talking MegaSquirt? Or are you going to use Ryan Hess (I think that's the dude on Fiero.nl) who modifies older OEM GM PCMs? I know a few guys were in the process of mating that trans to the N* but I thought they hadn't finished yet? Correct me if I'm wrong but that's a manual right? If it is that'll take a lot of the pain out of the equation since there won't be any need for a trans controller. Also, what is your build time-frame, budget, and most importantly schedule? Do you want to do a low-cost initial setup w/the engine N/A so you can get the stand-alone on and tuned to ensure everything like fab work, CV axles, etc all work/jive, THEN move on to adding boost, applying the required mods, but leaving the block/heads stock for test purposes, OR do you want to tear down the engine and put in lower compression ratio pistions, forged rods, may as well do all the seals, timesert the block or put in head-studs at that point ON TOP of turboing the engine? I don't know what skill/time you have so I'm just trying to see what would make the most sense.

I would also HIGHLY reccommend talking to the guys who have completed the swap in a Fiero over on .nl and then apply it to your car, afterall like you said the main difference is the subframe/mounts/cutting/fab work. The rest can be sorted w/time. If you are going MS, talk to me, I'll give you some references on people who have MS'd N*s over on MSEFI forums who may be able to help specfically w/your engine, but tuning is tuning and I can help there as I've done it on my XR4Ti track car. The older non-COP seem to be easier to MS if that helps as well :) Goodluck...

12-19-08, 11:38 AM
Someone also needs to check whether the earlier (pre-2000) Northstars had hypereutectic or forged aluminum pistons. Hyper pistons do not like lots of boost or nitrous heat.

12-19-08, 01:22 PM
Hi Raze,

thank you for the responses.
Bill has actually been racing Toystar. He just hasn't updated his site. The car runs/drives.

As for the EMS, I haven't decided yet. Ryan's system is intersting, but the LS1 solution might be better suited to my wants (eventual boost).

I did not plan to run Megasquirt. If I was going to run something that was non-oem, I would have to consider the more expensive systems, due to the reasons Ryan cites on his website and thread on Pennocks Fiero forum.

Yes, I am familiar with what is involved when converting a NA engine to boost. I think Jeff Hartman's book is a better than most websites, but thats IMHO.

The GM F40 is a 6 speed manual trans with a hydraulic TO bearing. The Fiero guys have done the N* + F40 multiple times now, and it is a well known/sorted combo.

I have read most of the Fiero forum swap info, so that's covered.

As far as budget, originally, I wanted to do this swap into my good MR2 http://www.cbulen.com/mr2 but I have since decided to buy another MR2 (a real POS that I got for very little $), and it is currently in my garage, and I have removed the engine/trans. I already have a brand new F40 trans, and a complete set of brand new Pontiac G6 axles, which consist of the left and right axles with CV joints, and an intermediate jackshaft with a carrier bearing and bearing support that bolts to the block (probalby won't bolt up to the N*).

I have an Audi V8 (1997 4.2 ABZ engine, rated 295 hp, 295 ft-lbs of torque), and decided that the Audi created more problems than it solved. Its best feature is being only 20.63 inches long. However, I finally decided that the passenger side axle simply doesn't have room to clear the block skirt, not to mention a few other problems that require some really creative solutions. The Audi is a very strange motor, as the block skirt sides are not parallel to each other. There is a huge dogleg to go around the oil pump. The Axle needs to go right through the oil pump (right through the block skirt), and the timing belt oil pump pulley. Some have suggested dry sump, but the pump pulley is still in the way. There is an easier solution (N*).

You see, the original goal was to find an engine/trans that did not require cutting the car to fit. The Audi + F40 achieves this goal, but has the axle clearance problem, and a few other problems.

If you want, you can read all about it here: http://www.motorgeek.com/phpBB2/viewtopic.php?t=19049
I have photos and video in that build thread. My friend Mike_H decided to go longitudinal with the Audi and an Audi trans, and he did some MAJOR cutting and fabrication on the car.

Last week, after putting the Audi V8 into the engine hole in my Mark2 MR2, I finally decided that the problems the Audi created were not worth the solution (worth the tradeoff). I decided i would be better off with a N* + F40. No axle clearance issues, or starter, or anything really. It does require cutting the car. That is the tradeoff.

Anyway, I can assure you that I have the time/skills/money for this project, I am now just looking for the best way to implement it. This is basically my second go at it, as the Audi will not work very well, so I rethought my project and my goals.

Thanks for the info on the N*'s. I needed to ask because I had not looked into this engine before, as I rejected it early on as being too long, so now, a year later, I am looking more closely at it, and I am now willing to cut the car to make it fit. Based on the info I gathered here and on the Fiero forum, I think I want a 95-99 Northstar.

The goal right now is to get the N* + F40 into the car, and then I can determine how much cutting/fab is needed on the subframe of the car. The axles are easy, I just need to get the right lengths, and then I can send them out to be shortened/resplined to fit the outer CV joints (Rzeppa) on the MR2 mark2.

As far as skills, I can work on cars, run a lathe and a mill, and weld. I have been working on cars since high school, helping my dad with motor swaps, and working on my own first car myself. My MR2 gets worked on only by me, and I am not talking basic maintenence--I took apart the motor 2 summers ago, and put it back together in aobut a month and a half. Then I increased the hp of the motor by about 35% (turbo motors are wonderful, especially at altitude like in my home of Reno, NV), and have had 10,000 trouble free and very fun miles since. What I am trying to say is that I am a pretty good mechanic.

I should also mention that I am a Mechanical Engineer. BSME Oregon State.

More importantly, I live sports cars. I breath them. I have loved mid-engined sports cars ever since I saw a Pantera when I was 17. I just can't afford the exotics, but who knows, maybe some day....
The problem is that I am too cheap to own one. Comes with being a business owner. I have found that I know more than most mechanics. That scares me. I can't stand the fact that you cannot work on your own Ferrari ever since the early 80's.

Ok, I got a little off topic-- I won't try to boost the motor until after the car is up and running. One of the reasons why I want boost is due to living in Reno. The local sports car shop (with a chassis dyno), has confirmed what I found through calculations: NA engines loose about 18% of rated hp at this altitude. So, a 300 hp N* (crank HP), is down 54 HP just by being in Reno. Currently, my 3S-GTE (MR2 turbo motor) is making 227hp AT THE WHEELS. So, I want a V8 and I want boost.

Bill Strong
01-10-09, 01:11 PM
Still here guys.
Yep the car was running. had a few issues. The SCCA would not let me race with the manual shifting automagic tranny. So I have been building up a 5-speed, but as of yesterday switched to the G6 F40 6-speed.
I have just not updated the website in quite awhile. I was getting too much BS from the kiddie hondah boyz. Made it easier just to keep the updates to a small group. The Internet can be a wonderful place.. sometimes.

01-12-09, 09:51 PM
LOL, heard that Bill, and thanks for the update! I can't believe we attracted your attention. Trust me when I say some of us are very interested in things like this, If you haven't already you might try posting your car/build info over on grassrootsmotorsports, never met a better crew of relativley unbiased gearheads who appreciate 'unique' over fan-boyism...

03-16-09, 05:46 PM
I am thinking of going with an LS Controller Kit for my 1996 Northstar (Vin 9). I have heard that it is very easy to adapt this controller to run the Northstar.

I can't post links yet, so the controller info is at
www dot gmperformanceparts dot com / Parts / LS_Controller_Kit.jsp

Can anyone point me to some information on using this controller on a Northstar?

Also, please check out my new website for this project at www dot MV8R dot com


03-16-09, 05:59 PM

04-24-09, 12:53 PM
Can anyone tell me if the N* is tilted towards the rear of the car in any of its stock applications (transverse applications). If so, how much do they tilt the motor?

04-24-09, 01:10 PM
I think the tilt is built into the engine. Just look at the seem where the oil pan meets the block. That seem should be level with the car.

Awesome project btw!

04-24-09, 03:13 PM
Thank you for the comment.

Regarding the tilt: I just went out and looked at my 1996 El Dorado Northstar, and I do not see any tilt built into the engine or the pan. It looks like it was meant to be straight up and down.

04-24-09, 03:15 PM
Here is a drawing of what I need to do (please note that this drawing is not of a Northstar, but of the Audi V8 in an MR2, I was previously going to use before switching to the N*, but the same principal regarding tilting still applies)


04-25-09, 09:56 PM
Well, if you were to use the stock placement and size of the alternator, the widest point would be from the outside of the right bank valve cover to the outside edge of the alternator which is about 28". If you take off the alternator the widest point would be from valve cover to valve cover which is about 27". I'm not entirely sure about what problems would arise from tilting the motor. I don't think it would cause any problems though, depending on how much you tilt it.

04-25-09, 11:00 PM
I have determined that I need to tilt it 7 degrees. Tilt it this much so the heads of the motor tilt towards the rear of the car.

06-02-09, 03:24 AM
3 and 1/2 motor mounts are made out of 4 planned mounts. I still have to come up with a jackshaft support as well. i am modifying a V8 archie support.

I should have done this when I first got the engine, but I did a compression check today

Except for cylinder #5, I got 155 to 195 psi on the other 7 cylinders.
On cylinder #5, I got 100psi

So, I called Alan at CHRFab.com and he told me how to do a leakdown test. I found that Cylinder #5 leaks a lot of air out the exhaust port no matter where the engine is in the rotation. I confirmed this by checking a good cylinder and it barely leaked out the exhaust. So, I think I may have a stuck exhaust valve, but I won't know for sure until I pull the head.

to do this, I will need to get a GM shop manual.
For some odd reason, the 1996 Cadillac Deville,Deville'D Elegance,Concours,Eldorado service manuals are more expensive (used) that other years

Questions: Can I use a 1998 manual just for the engine information, and possibly the engine wiring diagrams? The 1998 3 volume sets are only $35 to $40 used.

If not, what year GM genuine service manuals can I use, and for what models of cars?

06-02-09, 12:30 PM
They're slightly different 94-96 OBD-I vs 97-99 OBD-II vs 00+ (also OBD-II but used COP and revised half case and water cross-over).

I'd go with the right manual for the job.

Pulll the valve covers first and inspect the valves. Make sure there's no FOD holding the exhaust valve open, if it is open more than a tick you might have and a piston impact which would cause some other damage. If it's free floating you may be ok...