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1978 320I 5 Speed For 2002


Mort

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Hello,

I have a 1976 2002 automatic that mechanically is very stock. (I still have the solex carb!) I am new to the car and love it but I have been lusting after a 5 speed. Recently I heard about a 1978 320i that reportedly has a good 2.0 engine and a 5 speed. I have not looked at it yet, as it is several hours away, but wonder if this could be a good donor car for my 76. From what I can tell from online info, this 5 speed could be an early year option or a swap from a later year 320i. I have a few questions that I hope the very knowledgable members of this forum can help me with.

1. If this is an early year 5 speed, is that an issue at all? Most of the online info talk about later year 320i's.

2. From my reading, I believe I can use the flywheel. Any problems?

3. What about the pedal box, clutch master cylinder, etc. ?

4. Would it just be easier to swap in both the engine and transmission? Fuel injection is a big plus in my mind, especially after fighting with hot engine starting on my solex carb.

5. I would likely pull and swap the rear brakes, any other must swap items?

Thanks in advance for all the help!

Mort

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Some answers/thoughts:

 1. If this is an early year 5 speed, is that an issue at all? Most of the online info talk about later year 320i's.

       Two liter E21s didn't come with 5 speeds (they have 3.64 diffs and 4 speeds; 1.8 liter cars hve 3.90s and 5 speeds) so make sure  the car actually has a five speed gearbox.  All E21 5 speeds will work on your car but the three piece case 5 speeds (80-81 cars) are reckoned to be sturdier than the later two piece cases (82-83)

2. From my reading, I believe I can use the flywheel. Any problems?

    I belive that all E21 engines came with 215mm flywheels; it'll bolt right onto your 2002 engine.  Check archives for the proper throwout bearing to use--my conversion was to a 228mm flywheel, which uses a different T/O bearing.
3. What about the pedal box, clutch master cylinder, etc. ?

    You'll have to use the E21 clutch slave cylinder and get a new flex hose to mate it up to your M/C--suggest getting a stainless steel braided hose from Ireland as you really don't want to have to replace it.  And you'll need to get a pedal bucket from a stick shift car.  You could get the brake and clutch pedals from a stick shift car and install 'em in your automatic pedal bucket, but you'd have to cut holes to mount the clutch M/C, and that hole is reinforced on the stick cars...so it'll be easier to just get the whole stick shift pedal bucket assy...shouldn't be hard to find. 
4. Would it just be easier to swap in both the engine and transmission? Fuel injection is a big plus in my mind, especially after fighting with hot engine starting on my solex carb.

     I'd stick with the car's original engine.  The Bosch K-Jetronic as used on the E21 is pretty primitive as EFI systems go, and it's getting difficult to find folks who can work on 'em.  If you're determined to convert to EFI, you'd be better off to get the Motronic system off an 84/85 E30 318i, or put together a Megasquirt system.   You can help your starting problems by converting to a manual choke Weber 32/36.  I'm amazed that the automatic choke on your Solex is still functioning...mine was dodgy when the car was six years old...
5. I would likely pull and swap the rear brakes, any other must swap items?

     Unless you're gonna track the car, the stock rear brakes will do you just fine for street use, including "canyon carving" and autocrossing--even driving schools.  Again, if you're bound and determined to "upgrade" your brakes, you should go for rear disks, not just slightly larger drums.  Lotsa archive material on upgrading rear brakes as well as other goodies to grab off a parts E21.  

 

BTW, if you do highway driving, you'll love the 5 speed as it will lower your revs at a given speed by about 800, so 74 mph is about 3200 rpm vs 4000.  

 

Check the parts for sale section on the FAQ--someone has a rear disk brake setup for sale, and another has a selection of 215 and 228mm flywheels--just what you need!

 

Cheers and good luck

 

mike

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I just got done with mine, best and most satisfying upgrade I've ever done. I'm now a terror on the interstate. Make no mistake, it isn't a cake walk especially going from an auto, but it's so so sooo worth it if you get it right.

 

Follow these guides:  http://www.bmw2002faq.com/topic/131907-the-ultimate-5-speed-conversion-page-for-getrag-245/

                                   http://www.lexam.net/peter/carnut/5-speed.html 

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Wow, great answers, thanks for all the info. One area that I am a bit fuzzy about is the conversion from automatic to 5 speed and the resultant change of the pedal box and addition of the clutch pedal, clutch master cylinder, etc. Will any of the e21 parts work here? I am trying to budget how much $ the swap might take and see what parts I would have to line up.

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You can also modify the automatic pedalbox with parts from a rusted- out 2002 manual box- I've done it at least twice.

 

Dunno why the autos don't seem to rust so bad, but it's just a bit of cutting and welding.

 

The 320 was completely redesigned from the 2002- it's a lot more like a 520, with hanging pedals, not a floor- mounted box.

 

As to the gearbox itself, yes, in 1978, you COULD get an optional, close- ratio gearbox in your

320i.  It was not a cheap option, nor easy to find, so there aren't very many of them in the US.  At all.

Canada may have gotten a few more. 

 

So it's

a- pretty unlikely that it has a 5- speed.  Triple- check that before you even go. 

     So if you go, go with a jack, some jackstands, and good lights and take pictures, because what you find

     may be not what we're used to seeing.

 

a1- if it IS a close ratio box, buy it.  They are rare.

a2 if it is NOT a close- ratio box, you can still use it.  If it's a 3- piece, bonus.  You CAN use the less-

desirable 2- piece if it's in good shape- they aren't all that bad, really, if you keep fresh fluid in 'em.

 

Yes, the front hubs are worth something to tii people.  Yes, you can use the rear drums for a noticable improvement

in rear braking... what, you say, you can't tell what your rear drums are doing?   Then maybe you won't notice it after all...

 

And yes, you CAN use the EFI, but the best use for it is as a platform for Megasquirt- several have done it, and it looks

great and performs well.

 

what I think,

 

t

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I doubt that the 78 320i came with a 5 speed but the previous owner could have converted it from 4 speed to a 5 speed. +1 on the previous posts that a 77-79 US spec E21 came only with a 4 speed and 3 speed autotragic. An 80-82 E21 5 speed donor car is what you are looking for in regards to a donor car. An 83 E21 5 speed will work but it's not as desirable as the 80-82 models. Here is everything you need to know about doing a 5 speed conversion in a 2002.

http://www.lexam.net/peter/carnut/5-speed.html

 

G-Man

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I just finished an automatic to 5 sp swap about six months ago and love it. Read the link supplied by G-Man. It's a good guide for auto to 5 sp swap and will give you a good idea of whats involved. You have a few options if you are using the '78 320i as a donor if it has the right transmission. You can use the engine or keep it as a spare or sell it. My car has an engine from a '77 with the 02 manifold and carb. If you use the engine, you will need to swap the oil pan and oil pump to fit in the 02. Either way, you will need the flywheel, trans and drive shaft. Don't know if the drive shaft will be the right length but will still be needed if it needs to be rebuilt. I found a pedal box from a manual for my swap. One thing that does not seem to ever be mentioned, you need to swap the gas pedal lever from the auto pedal box to the manual box so it will clear the wider trans tunnel. BTW, an automatic car is good for the swap because it has a wider transmission tunnel and gives more room for the bigger transmission. Also don't skimp and use the old clutch MC and slave, buy new.

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