MV8R: MR2 with V8 1991-1999 generation

[cbulen]

I participate mainly in the a MR2 forum that does not have content spidered by Google, so you won't see any of the info there pop up on Google searches. As a result, many of you might not be aware of my project.

I am introducing, to you all, Project MV8R (named after the SARD MC8R LeMans MR2)

I have a 1993 turbo (my turquoise car) that will eventually get this powerplant after I get the bugs worked out. I am using a 1991 (red) MR2 as my test mule. My 93T is in beautiful condition, and my 91na is...........not

Anyway, the gist of the project is a Northstar V8 + GM F40 6 speed manual tranny, and hybrid GM + MR2 axles.
I know it has been suggested on this forum, as well as MANY MANY others that a 1UZ-FE v8 from a lexus should be used. This is impractical for many many reasons. The biggest reason is that it is simply too long to fit the 2nd gen chassis (and probably the first gen too). The front pulley would have to be inside of the tire. It just ain't gonna happen, folks.

Acutally, it could, but only if you want to build a whole tube frame for the rear of the car, and re-engineer the whole back of the car, and you must mount the motor longitudinal. In this case, the Lexus is not ideal, as the front of the motor would be in the cabin.

I decided to take a different approach. I went and tried to find an engine that would fit the mk2 transversely. I found one, the Audi ABZ, but found this engine was not suitable mainly because it was never offered in a transverse application, so Audi inconveniently put the block skirt, the starter, the oil pump, the oil pump drive, etc. in the way of the intermediate shaft and right axle.

Mike_H on the MR2 forums has done the World's First V8 2nd gen MR2. He used the Audi 4.2 V8 (engine code ABZ), and mounted it longitudinal. He used this engine because its around 6.5 inches SHORTER than the 1UZ. The Audi is 20.63 long, the 1UZ is around 27 inches. The N* is 23 inches long and required some cutting of the chassis, when I bolted it to a transaxle that is shorter than the Toyota MR2 turbo trans.

So, I decided to use the N*. This is an ongoing project. The N* now fits the car (a bit of cutting was required, but not as much as you might think).

If anyone would like more information on doing this swap, please PM me.
You can also sign up for my free newsletter. No selling, no spam, just good info for MR2 enthusiasts. http://www.mv8r.com

[Ghostyman]

Nice! Now the race is on between you and Bill to have the first Northstar MR2. I'm really looking forward to seeing the end result.

[cbulen]

THere's no race, Bill Strong's car runs/drives. He has raced it. He has not updated his Toystar site for some time.

Currently, he is changing the transmission from the caddy autotragic over to the F40. I brought it to his attention that the F40 6speed bolts up to the N*.
________
CBulen
Project MV8R: 2nd Gen V8 MR2 engine swap
MV8R.com

[MR2Jedi]

I've thought of using the NorthStar as a donor engine because of it's 4 valve/cylinder and transverse mounting. I didn't know that a 6 speed manual trans was available. Awsome!
It'll be nice for you to work out the bugs and share your experience. That'll save me or anyone alot of headache and trial and error. Looking forward to seeing the final product

[cbulen]

There are a couple of other nice things about the F40:

1) its 300 to $400 on eBay NEW NEW NEW!!! Apparantly, GM decided to surplus out the 2006 version of the F40, which has better gear ratios for a V8 anyway (Except 1st gear), than the 2007 version. The 2007 version still has a funky 1st gear too.

2) its rated for 295 ft-lbs in a 3500 lb car. This is one of the HIGHEST strength ratings for ANY front wheel drive manual transaxle, that we can get our hands on. There are some higher rated Getrags, but you cannot buy them anywhere (I have looked).
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[cbulen]

Oh, I have to give credit where it is due. It was the Fiero guys that figured out this engine and trans combo.

[MR2Jedi]

Originally Posted by cbulen

2) its rated for 295 ft-lbs in a 3500 lb car. This is one of the HIGHEST strength ratings for ANY front wheel drive manual transaxle, that we can get our hands on. ).

So is that the rating for the clutch? I would think the tranny for a V8 would be more robust than that.
Do you know what the top MPH is for the 1st gear?

[cbulen]

No, thats the rating for the engine torque the 6 speed can take, in a 3500 lb car. This transaxle is not meant for V8, its meant for a health 3.9Liter V6. It just shares a common bellhousing bolt pattern with the Nortstar, as GM used this bellhousing pattern across several cars.

There is no stock clutch for the Northstar. All Caddy's with Northstars are all Autotragics I may have found a flwyheel and clutch solution, but I am still talking to the manufacturer on that.

First gear is actually too low for a V8. its 3.77 and the final drive is 3.55, so your total reduction in 1st is 13.38 to 1. For a strong V8, it should be closer to 10 or 9 to 1.

Top speed in 1st, assuming normal size rear tires would be 35mph @ 6500 rpm. So, shifting at 20mph (shifting early) would probably work better.

Sorry for the slow responses. This board is weird, as it does not e-mail me, and there does not seem to be an option to make it e-mail me when I have a PM or reply to a post.
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[MR2Jedi]

There is an option for notificaion to respnses to subscribed threads.

[cbulen]

I finally figured out that my old, obsolete e-mail was in the TN system. I tried to change it, but the TN system would not e-mail me. that was last night. Tonight, I just tried it again, and it finally sent me a verification to my current e-mail.

MR2Bad, there is a thread on the MR2OC forum, where we have been posting lots of technical info on the GM 6 speed manual transaxle.

Today, I just got word that a company that makes a Northstar clutch and flywheel might have a clutch solution for us. I didn't get to talk to him yet, but I hope to tommorrow, and hopefully, I can confirm that the clutch will fit. The 6 speed is weird because it has an extra deep bellhousing, and in the original application, had a dual mass flywheel.

In addition, the TO bearing is a hydraulic unit, and the input shaft seal is integrated into it, so we are sort of stuck with using the stock TO bearing. Not a huge deal, but finding the plumping to plug into the TO bearing has been a bit of challenge, as it uses the GM proprietary quick-disconnects. So, because we have to use the stock TO bearing, we have to find a clutch that will fit along with a flywheel of the correct thickness. The Fiero guys have a spacer plate that moves the friction surface of the flywheel they use, furthur away from the flywheel to compensate for the deeper bellhousing. I might be able to eliminate that, and its associated rotating mass.

[cbulen]

Progress update: Yes, I am still working on this project!!

I have the front, rear, passenger and driver's mounts all partially completed. They are about 80% done each, only requiring some additional strenthening and stiffening webbing. They are currently more than strong enough to support weight. The Passenger mount is waiting on urethane bushings that are on backorder. The front and rear mounts are bolted to the car and the car is supporting the weight of the engine/trans!

I received the clutch disk, flywheel and pressure plate. The splines in the clutch disk were incorrect, due to a misscommunication, so I sent it back, and the clutch manufacturer (McLeod) changed the hub and sent it back to me. They turned in around in only a few days!

The next step is to drop the engine/trans, separate them, and install the clutch and flywheel and test the clutch acutation. I have a Pontiac master cylinder and plumbing all the way to the hydraulic TO bearing that came with the trans, so I should be able to verify if the clutch will work. Mainly the question is: is the flywheel the right thickness to work with this trans and clutch?

I also decieded to do a compression test. Cylinder #5 was waaay low, so I talked to Alan at CHRFab.com (he is a Northstar hot rod specialist, and he sold me the clutch kit and flywheel), and he told me how to do a leakdown test. I converted my compression tester into a leakdown, and found my exhaust valve(s) are sticking open. Given the low mileage of only 40K, I believe its just carbon buildup. The Salvage yard people think its this and possibly because my Northstar has not been run or turned over for the past 6 months. This is common with these engines because the people that buy Caddy's with Northstars drive like grandma/grandpa, so the carbon gets built up. Wide open throttle is good for an engine once in a while.
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If you are buying stuff for this swap, be sure to check your engine as soon as you receive it, while your 90 day salvage yard warrantee is still in effect. I forgot to because, sometimes, I am an idiot.

[MR2Jedi]

Originally Posted by cbulen

sometimes, I am an idiot.

Some pics would be nice.
I do enjoy your newsletter.
Thanks

[cbulen]

Ask and ye shall receive. BTW, the May and June newsletters were just posted to my site. I have implemented a new login system. Hopefully everyone who was already signed up recieved a confirmation e-mail and info on thier new login and password.

will repost the pix soon