Thinking about installing an BMW M6 engine in my Z

[EuroDat]

I'm with Captain. The synchros ard doing exactly what they should do and it's clear you have a synchronised reverse gear.

I don't think your problem is in the transmission.

Love the gadgets you create to test stuff.

Can you fabricate one to push the clutch fork in and measure how far it goes while someone tries to rotated a rear wheel? The rear wheel off the ground and free to spin ofcource. If it does disengage then you can measure how far you need to depress the fork to disengage the clutch. Then you have the data to work out what ratio master/slave movement is needed.

Do you still have the orriginal M6 master cylinder? I think you might have a ratio problem with the master and slave. Maybe the M6 master is a lot larger diameter or has a much longer stroke.

Edited April 14, 2020 by EuroDat

[grannyknot]

9 hours ago, Captain Obvious said:

So what the heck is wrong with the clutch system???

I aim to find out, I'm going to start pulling the trans tomorrow, hopefully it is something like a fork spring that jumped off.

6 hours ago, EuroDat said:

Can you fabricate one to push the clutch fork in and measure how far it goes while someone tries to rotated a rear wheel? The rear wheel off the ground and free to spin ofcource. If it does disengage then you can measure how far you need to depress the fork to disengage the clutch. Then you have the data to work out what ratio master/slave movement is needed.

As I mentioned before the bmw slave has a 16mm stroke and the new clutch MC  easily makes the slave extend fully so I know the clutch fork is getting enough movement to disengage but for some reason isn't, that makes me think there is something wrong with the fork alignment or maybe the pivot it's self.

I promise I'll show warts and all, I goofed up somewhere.

[LeonV]

Sounds like the shift fork isn't engaging the release bearing. I'm not familiar with the S54 but sometimes this can be fixed without pulling the transmission.

[grannyknot]

Yup, I certainly did goof up but I have a sort of plausible excuse!  I installed the clutch disc backward but on one side of the disc only there is a large embossed F so I assumed that's the front,  nope, that is the company logo of the manufacturer.  I should have checked my pictures.

But now that's it is all torn apart again I think I am going to replace the dual mass flywheel with a single mass unit, and eliminate another 15lbs.

Thanks for all the help guys.

 

[Zed Head]

You'd think a clutch disc manufacturer would know better.  A big old "F" on the backside of the disc?

So that nose/projection was jammed up against the crank shaft flange?

[grannyknot]

1 hour ago, Zed Head said:

You'd think a clutch disc manufacturer would know better.  A big old "F" on the backside of the disc?

So that nose/projection was jammed up against the crank shaft flange?

Yup, I'm surprised it even fit.

[Captain Obvious]

Wow, that's pretty bad. There's no way they should be putting a mark on like that. It's just bad practice.

So on the upside... Glad to hear you found the smoking gun, and glad it wasn't inside the case!  

[Casey_z]

Gives you something to do while self isolating

It is a relief to know anyway

I hope I can see this build this summer sometime

 

Casey

[EuroDat]

On 4/16/2020 at 12:03 AM, grannyknot said:

Yup, I certainly did goof up but I have a sort of plausible excuse!  I installed the clutch disc backward but on one side of the disc only there is a large embossed F so I assumed that's the front,  nope, that is the company logo of the manufacturer.  I should have checked my pictures.

But now that's it is all torn apart again I think I am going to replace the dual mass flywheel with a single mass unit, and eliminate another 15lbs.

Thanks for all the help guys.

For a fleeting moment I thought, "could the disc be backwards", but then I thought, No Chris wouldn't do that. Looking at the photos I can understand why it happened.

That is not playing by the rules of common sense. Bad move on the manufactures part. It's not even a special letter type, just a standard F.

[Captain Obvious]

For a fleeting moment I had the exact same thought. Almost even asked about it. But then I thought, "Chris would never do that."  I should have let Captain Obvious go free!  Haha!!

[grannyknot]

The clutch is working!

https://youtu.be/dVW8Qbv8208

 

Edited April 29, 2020 by grannyknot

[grannyknot]

So I have had the car out on the road a couple of times but being nice to it while  breaking in the new clutch and brake pads and there is 13 codes on the OBD2 reader.  I have ordered a bmw specific scanner to pick up the bmw codes so I can start to figure out where the problem lies.  Even with 13 codes it's running okay, some stumbles on acceleration and stalling if I come to a stop too quickly.

Already though I can tell the there is too much bias to the rear brakes, very easy to lock the rears up. I had a Wilwood proportioning valve on the last setup and couldn't tell if it was doing anything so before installing it on this brake system I thought I would try some testing.

Now fluid dynamics is a big subject and I only understand a bit of it but since compressed air was available to me I used it instead of brake fluid for my test.  I hobbled together some fittings that were air tight,  Wilwood says this unit will decrease the amount of braking pressure by 50% with the knob turned all the way up to the top of the threads, well I found that 33% was the best I could get from it.  The proportioning valve only has a 1000 miles use on it and is very clean inside.  I started with 90psi which resulted in 60psi for the rear wheels, with one full turn of the knob CW the pressure came up to 75psi, with one more full turn brought the pressure up to the full 90psi,  so all of it's proportioning takes place in the top two turn and there is still 9 more full turns left until the knob bottoms out.

So why are those 9 other turns on there? Just to confuse me I guess.  33% is more than enough to work with I think but I'm glad to know where range of adjustment is now, should make the dialing in easier.

3rd pic at 60psi, 4th pic one turn down, 5th pic 2 turns down.