79 635 Euro

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Adadebe

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I have a CR dog leg and a 3.07 LSD and a 3.5 engine all rebuilt by Korman - The components came out of a 79 Euro. The papers show that it is a STAGE 1. I will like to keep my 73 CS carburated (webers) and not fuel injection. It also came with a ceramic coated Stahl headers

My question

1)will all these components work on my 73 CS and what else do I need to do the conversion.

2) what is a STAGE 1

3) will 5spd OD be better than the dogleg?

4) Any advantage/disadvantage with the headers?

5) How difficult is it to switch the Fuel Injected motor to Carburated - what components will i need?

I'll apreciate any assistance. Thanks
 
To find what stage 1 is, you will likely have to call Korman directly. I'd guess it is a P&P with a mild compression bump. Since it is a 79 635, that means (if memory serves) that the engine is a M90, very desireable.

In terms of modifying the engine for carbs, I guess it depends on which carbs you want to run. The stock Zeniths do all right, but a set of 38/38 or triple 40 Webers would really do the trick. Since it isn't a stock engine, you will have to do some carb tuning, possibly some re-jetting. You will have to use an electric fuel pump, as the M90 head doesn't allow for the original mechanical fuel pump. The early FI systems used the same dizzy setup as the carbed cars so that shouldn't be a problem.

Personally, I prefer the OD box over the CR one just because the M30 and M90 aren't very peaky engines, so it isn't like you have to keep it in a certain rev band all the time. However, since you already have the CR box and the 3.07 sideloader LSD, why not use them?

No disadvantage I can think of with the headers. If you've got them, use them.

Sounds like a fun build.
 
Korman's website (http://www.kormanfastbmw.com/) lists the stage 1 for US market 635s as:

Korman Stage 1 3.5L Fuel Injected Engine-Late (88-89 635csi)

Stage 1 porting and polishing, balanced connecting rods, light weight piston pins, increased valve spring pressure, and a performance computer chip increase horsepower from 208 to 222, and torque goes from 223 lb/ft to 237 lb/ft.
Click to expand...

It's probably more of the same for the euro motor, which was rated at 215bhp when new. The US motor was 185bhp out of the box.

You realize that the CR 5-speed has a 1:1 5th gear (same as 4th in a non-OD box), right? What differential will you be using? The 3.07? A 5-speed and 3:45 or 3.25 (from an automatic) might be more useful and fun unless you're going to track the car. You could pay for the whole thing if you sold the CR. They go for good money.

I suspect that E24 headers will hit the front subframe. They could probably be modified, but a new e9-specific set may be less hassle.

I'll second xatlas's suggestions for carbs, though a conversation with Korman would be in order. They might suggest a more aggressive cam grind for 40's x 3. Nothin' wrong with EFI, either...
 
Atlas & Mike, thanks for your thoughtful responses - I have 2 new webers 38/38 with electric fuel pump on my car now and plan on using those. It sounds like I may have to use an OD (I don’t plan on using my car on a track) I do have access to an OD box.

Will the current differential on my car be OK with an OD box?
What differentials did 73 CS come with?
What about using an OD box with the 3:07 LSD and the euro engine?


This statement though bothers me

"I suspect that E24 headers will hit the front subframe. They could probably be modified, but a new e9-specific set may be less hassle"

I hope you are wrong here – any one else want to confirm these?
 
your build plan sounds fun and similar to my set-up:
dual 38s, P&P head with a cam, dog leg box, LSD...

you might want to try the tranny combo out before you start swapping, a CR box creates a very nice even pull all thru the gears, an OD box has a long transition/pull from 2nd to 3rd.

with your 3.07 LSD and the CR box, it might be a nice cruising combo, I have a CR box with a 3.45 LSD and I run 70-80mph at around 3500rpm, your highway rpms I'd guess will be lower......

it's much easier to swap LSDs than trannies.....

if ya want to rid yourself of the 3.07 LSD let me know......:wink:

just my 2 cents & HTH
-shanon
 
Adadebe said:
This statement though bothers me

"I suspect that E24 headers will hit the front subframe. They could probably be modified, but a new e9-specific set may be less hassle"

I hope you are wrong here – any one else want to confirm these?
Click to expand...

I think you will find the headers will fit ok, except where they connect to the front muffler. I can't remember whether they are shorter or longer than the E3/E9 headers there, but either way is not difficult to adapt. You'll either have to add a little pipe or cut the header end.

I've had headers on 2 coupes now and can't really say you get much other than the "wow" factor when you open the hood. The factory system is really pretty good, especially the earlier manifolds before the EGR takeoff.

The change from 4 speed to 5 speed overdrive was one of the most satisfying changes I've made. Highway travel is much improved, especially if you have a noisy modified engine.
 
hmmm

a friend found out the hard way that the exhaust from early 6ers with E12 body, will not fit later 6ers built on the e28 chassis.

This of course does not prevent the motor and exhaust from fitting the e9 chassis. I have 528i headers in my '73 coupe. they were a real b*tch to install but once in, they run just right. I had to trim 2" from one header pipe, and then they mated to the rest of the stock exhaust without any trouble at all. Oh, but I remember fumbling about for hours trying to get them in...
 
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