Hello All

I've a 1989 635CSI Highline which I've owned for 2 - 3 years, I'm lucky to have a TVR Griffith which satisfies most urges in the 'need for speed' department.  A little while ago I was concidering selling the 6, but I knew I would eventually regret this - so I needed to re-kindle my interest in the motor in some way - solution was modify!!!

I post on Bimmerforums a bit and take advice when I can, so I wanted M6 or better and proceded to buy a few bits to this end. 

At present I've got a S38 (3.6 and 315bhp) from a 1991 M5, a Getrag 280 5-speed manual gearbox and a reconditioned M6 differential.  My pal and I are going to fit the diff next week and work forward from that, there's no great hurry and I want the finished job to be good/special.

So has anyone done this in the past (hoping to short-cut the numerous problem I WILL come up against).  Anyone any thoughts on this (all input is welcome).  I think my biggest initial problems will be engine mountings and exhaust manifold - so some custom work will be needed!!!

I'll post pics etc when something is achieved, so it'll be a doddle for the next person

Cheers Dave

I found this and just PM'ed the guy, lets hope he can help.

http://bigcoupe.com/phpBB2/viewtopic.php?t=589&postdays=0&postorder=asc&highlight=engine+install&start=0 - http://bigcoupe.com/phpBB2/viewtopic.php?t=589&postdays= 0&postorder=asc&highlight=engine+install&start=0

Paul,

I've got an 89 highline auto which i bought with the intention of converting to manual. When searching for the parts required i ended up with a complete LHD M635 so now i intend to swap engine as well as gearbox etc. At the moment i'm rebuilding the M635 suspension & brakes prior to swapping them onto my car & then i'll look at the drivetrain etc.

Look forward to your updates !

Cheers, Dave.

dave635 wrote: Paul, I've got an 89 highline auto which i bought with the intention of converting to manual. When searching for the parts required i ended up with a complete LHD M635 so now i intend to swap engine as well as gearbox etc. At the moment i'm rebuilding the M635 suspension & brakes prior to swapping them onto my car & then i'll look at the drivetrain etc. Look forward to your updates ! Cheers, Dave.

Beware.  LHD exhaust manifold will not fit a RHD car.  If it's the snake like equal length headers you have on the LHD car then you will need to get hold of the RHD manifolds.  The LHD manifold hits the streering box on a RHD car.  New RHD manifold from BMW is 800 plus!!

Good luck with it though.

Ian

ian M635UK wrote: Beware.  LHD exhaust manifold will not fit a RHD car.  If it's the snake like equal length headers you have on the LHD car then you will need to get hold of the RHD manifolds.  The LHD manifold hits the streering box on a RHD car.  New RHD manifold from BMW is 800 plus!!

....which will only encourage him to go stainless steel

dave635 wrote: Paul, I've got an 89 highline auto which i bought with the intention of converting to manual. When searching for the parts required i ended up with a complete LHD M635 so now i intend to swap engine as well as gearbox etc. At the moment i'm rebuilding the M635 suspension & brakes prior to swapping them onto my car & then i'll look at the drivetrain etc. Look forward to your updates ! Cheers, Dave.

How cool is that, mine is a 1989 auto.  You should be able to help me with conversion to manual etc, and I wouldn't mind knowing the differences in the suspension 635 to M6 - alot of water to pass under that bridge as i haven't started yet, hope to start next week.

Maybe we should post the pics/info/experience as we go along and compile them into something more interesting later.

Good Luck Dave.

first - thanks Ian for the info on the manifold, the car does have the snakelike manifold & its a great shame that it doesn't fit the RHD cars. I've been looking for second hand RHD M635 or M5 manifolds for a while now but may end up going for a custom build as per Horsetans suggestion (or try a bit of persuasion on the one i have...).

second - Paul, there are differences to the dampers (Bilstein sport) & springs (stiffer) at both ends of the car & i believe the ride height is reduced by 10mm or so. Brakes are 4 pot calipers gripping 300mm discs up front & standard 635 at the rear, i have a set of E34 M5 rears for my car.  Some M635s had the thicker M5 anti roll bars, mine has the std 635 ones so i am planning to change these also. good idea to keep posting progress & help each other out where possible.

Cheers, Dave.

Fritz bits has just completed work on a RHD Stainless steel manifold for the M635csi. This should sort out your problems.

Suspension and brakes wise the cars are miles apart.

On the brakes department fit E34 M5/540 brakes. The M5 fronts are slightly bigger, but either conversion will out brake a standard M6.

Suspension wise the M6 had Heavy Duty(HD) Bilstein dampers. There was also an option of Sport Bilsteins (SP) that were one inch sorter. Springs are indeed lower and significantly stiffer. Anti roll bars are slightly bigger, but you can get the massive 25mm M5 E28 ones and modify them and that will stop roll considerable although the matching 18mm rears are no longer available.

The diff is a different size and i am told may need a bit of modification of the floor to make it fit. Battery is located in the boot.

I have actually driven an M635csi that had a 3.6 M5 lump in it. Was a very quick beast.

Good luck

James

Cheers Sohlman,

For everyones info, i just took delivery of a new 18mm rear ARB, supplied by a BMW dealer (In Germany) after about a 4 week wait. It is the correct item with the BMW part number & interestingly an Eibach logo. Cost was £63, possibly cheaper via Eibach direct.

have also heard that the standard boot floor may need some modification to accommodate the M635 diff but not sure if this is actually correct, will post findings in due course.

Cheers.

18mm rear bars now availbale from BMW!!!!!!!!!!!!!!!!!!!!!!!!!!

Was yours old stock?

I waited nearly a year for an 18mm rear bar on back order.  Ended up with a 19mm Dinan instead.  Good news if BMW have manufactured some more 18mm rears.   These with 25mm fronts transform any 6 series

Ian

ian M635UK wrote: 18mm rear bars now availbale from BMW!!!!!!!!!!!!!!!!!!!!!!!!!! Was yours old stock? I waited nearly a year for an 18mm rear bar on back order.

It passed to me....

These with 25mm fronts transform any 6 series

That reminds me......