MR2 Spyder / 3100 Swap

[dmc12mk3]

Hi guys, I'm new to your forums and the search wasn't helping me out on what I need. To give some background, today I picked up the complete 3100 motor that I plan to put in my 2001 MR2. I've gotten most of the details sorted (bellhousing adapter, pilot bushing, mounts, exhaust, fuel, wiring, etc). I am curious about the V6's crank shaft.

Currently, I plan to use the Toyota clutch disc with the V6 pressure plate and flywheel that I have. The Toyota disc is signficantly smaller than what the V6 uses, but there isn't another diameter disc available for the input shaft of the 6 speed transmission I have. I'm curious if GM made a four cylinder engine that might have a smaller zero balance flywheel that would be able to bolt up to the V6's crankshaft. Anybody here with experience regarding these two things? Basically I'm looking for a smaller machined surface flywheel that can attach to this crankshaft.

What I have will get me by and prove the concept to me, but I'd like to be able to stand a little more torque through the clutch setup if I could. Thanks for your time.

[Guest]

RE: MR2 Spyder / 3100 Swap

No, the 4 cyl engines used the flywheel as the V6s.

What I would probably do, if the flywheel surface allows is mate the MR2 pressure plate to the V6 Flywheel, this will provide a better surface on that side of the disc, I'm not familar with the MR2 clutch assembly though, to know if the entire flywheel surface will be covered by the V6 flywheel, pics might help.

What is the input spline count and diameter of the 6-speed? There might be another combination to use.

[dmc12mk3]

Re: RE: MR2 Spyder / 3100 Swap

No, the 4 cyl engines used the flywheel as the V6s.

What I would probably do, if the flywheel surface allows is mate the MR2 pressure plate to the V6 Flywheel, this will provide a better surface on that side of the disc, I'm not familar with the MR2 clutch assembly though, to know if the entire flywheel surface will be covered by the V6 flywheel, pics might help.

What is the input spline count and diameter of the 6-speed? There might be another combination to use.

The trouble with the V6 flywheel is that the clutch disc from the toyota transmission (C60) is too small to mate 100%. It would get me by and allow me to drive the car, but I wouldn't want to leave it like that without correcting the issue. The clutch disc diameter is 8 5/8" as I recall. The input shaft of the C60 is a 15/16" diameter shaft that uses a 21 spline disc. Renault is the only other car manufacturer that makes a larger disc for the 15/16" 21 spline shaft and its only 8 7/8". Still not enough to solve my problem as I'm looking at a 1/2" or so gap to fill. I would be glad to take pictures, I have a complete clutch/pressure plate/flywheel for the V6 and a pressure plate/clutch setup for the toyota laying on a shelf in the garage. I can put the disc on the flywheel and show you what I'm working against.

I was just going to use the V6 pressure plate to press the toyota disc. Saves me the trouble of having the flywheel drilled for a toyota pressure plate and accomplishes the same task. The only thing I was concerned with was the toyota throwout bearing being able to work against the diaphragm of the V6 pressure plate, but after seeing a few pics (haven't bought the TO bearing yet) I don't think it will be an issue.

Thanks again.

[dmc12mk3]

I took pics, haven't got them loaded yet but I will take care of that later on tonight or tomorrow. I also took measurements of the inside diameters of the toyota clutch disc and the GM flywheel. The GM has a 5 and 7/8" diameter gap from one side of the machined surface to the other. The toyota disc is used to a 5 and 1/2" diameter gap from one side to the other so as it stands with the Toyota disc - I have 28.347 square inches worth of clutch surface total. If I use the GM stuff with the extra gap I will only have 24.649 square inches of clutch surface. I'll still be retaining 87 percent of my surface area even with the loss of the ~3.6 inches of surface area. I can live with that. My original math on this was way off to say the least. I was working from the outer diameter of the clutch requirements, which needless to say, was not where my deficiency was.

What tipped me off to this was when I set the toyota disc on the gm pressure plate and I could see that I was only missing it on the inside by an 8th inch or so. I was thinking I was well over a quarter of an inch all around which would not be substantial enough to really push on the V6 when I get it running.

btw - my calculations are only for one side of the disc. Obviously the disc has two sides to it. I wanted to make that known just in case someone didn't assume as much.

[Guest]

I assumed you meant only one side...

As I was falling asleep last night I had an idea about this, kinda off the wall, so try and follow me, I hope I can explain it.

You have to make an adaptor plate to adapt the engine block to the tranny, so that will add some space, say 1/4" to 1/2", so you will have to space the flywheel equally. What I'm thinking is that there might be a way to adapt the Toyota flywheel here. Throuhg use of an adaptor plate, or my really wacky thought, use the 660 flexplate, and bolt the Toyota flywheel to it. This way you have the proper ring gear for the 660 starter to engage and the clutch surface is complete covered as per factory. You may have to make the adaptor plate thicker or thinner depending on how thick this assembly becomes.

Like I said wacky thought, but might work.

[slick94prix]

Wow, this should be one fun car!!!

I really don't know the answer to any of the questions above, but just the fact that this would be a fun project to take on.

Anyways, good luck!

[dmc12mk3]

I won't need to worry with the flywheel I don't believe. I'm backing the transmission out a 1/4". Toyota C56 (5 speed) and C60 (6 speed) transmissions do not use pilot bushings. My only concern is being too close to the flywheel actually. A quarter inch won't be enough to affect the throwout bearing's alignment to the diaphragm, so I should be good there too. Here's some pics I took of the discs and stuff if you guys are interested. The rusty bits are the V6 parts that I will need to clean up before use - the smaller pressure plate is the Toyota and goes with the disc next to it. Also, the v6 parts will be replaced with new stuff as soon as I confirm that this is a doable project.

Edit - Raven, I like the idea of using a flexplate to bolt the flywheel too. If I did something like that I could maintain the exact factory specifications as far as the clutch goes for the Toyota. I will give it some thought. Thanks!

[Guest]

Looks like it should pretty much go together and work, Do you have a V6 clutch plate to have a comparison between the Toyota plate and the GM plate? Pics are great, but a litle hard to see, but your measuments are the key here.

I think my idea might work, it was just a thought that came to me, let me know what you find if you look into that.

[dmc12mk3]

Looks like it should pretty much go together and work, Do you have a V6 clutch plate to have a comparison between the Toyota plate and the GM plate? Pics are great, but a litle hard to see, but your measuments are the key here.

I think my idea might work, it was just a thought that came to me, let me know what you find if you look into that.

I do, the GM clutch disc is a good bit bigger. It takes up the entire surface area of the pressure plate that I snapped a picture of and you can see how much bigger it is over the Toyota disc.

Yanked the 2zz/6 speed out of the Spyder last night. Even did a little write up on it for my buddies. Though most Spyders on the road do not have a Celica GTS platform in their car. I can't help myself when it comes to more power, hehe.

I should know whether or not the V6 will physically fit in the engine compartment by Friday.

If anyone is curious:

http://www.wheresmyjeffdickey.com/spyderenginedrop.asp

[Scott_68B]

Did you consider a custom clutch? I did a quick search and came up with this:

http://www.best-bilt.com/

Don't know anything about them but maybe they can come up with something obscure that works out of the box or make something up for you. Just a thought.

-- Scott

[hamondale]

Did you consider a custom clutch? I did a quick search and came up with this:

http://www.best-bilt.com/

-- Scott

Valley Clutch in Irwindale CA built me one back in early 90s. Still working. They are still in biz, might be another option.
See http://www.valleyclutch.com

[Doubt_Incarnate]

it almost seems like an interesting 6 speed swap for a j-body... except all the axels and stuff, mounts. and i dunno, how is the shift done, with a rod isnt it? that would be a tricky thing to do with cables. is the tranny on the drivers side of the car?

[bszopi]

I'm pretty sure MR2s are mid-engine, RWD, therefore the trans would most likely not be a transaxle, but an actual transmission. But I've never really looked at one, so I'm just guessing...

[dmc12mk3]

MR2's have a typical FWD platform (transmission on the drivers side, engine on the passenger's), its just stuck in the back. Toyota only offers them with a 5 speed and 1zz engine though. However, they offer the exact same platform in the Celica. The Celica also has an optional engine/transmission combo that is a 180hp dual cam profile (vtech, or Lift as Toyota geeks call it) mated to a 6 speed. Its physically the same motor on the outside, though they share almost nothing in common on the inside. Shifting is done via two cable linkages. On the Spyder, the shift gate is determined solely by the transmission. I'm trying to avoid too many custom parts as I am looking to develop a kit for this.

[dmc12mk3]

Another question that I have.

If I were to decide to use a GM 5 speed, what would be my best bet? Basically I'm curious as to whether or not there is a significant size difference between the different FWD manual transmissions GM offered for the 60 degree v6's.