Kato Kids BMW M3 powered 71' 240Z

[KatoKid]

I wasn't happy with the clearance between #6 primary pipe and the steering shaft. Spacing the engine/rack crossmember down to get the driveline alignment correct also had the undesirable effect of moving the steering shaft even closer to the chassis rail, it was already close as a result of the WRX rack installation so I needed to gain some clearance from the chassis rail by moving the base of the column up and towards the exhaust which in turn bought the #6 primary pipe closer to the steering shaft. Its been bugging me all day thinking about if I can get some more clearance so I ripped out to the shed as soon as my daughter was in bed.

 

I unpicked the tack welds and slightly deformed the pipe near the collector just enough to be able to lay the #6 primary pipe hard on top of the #5 primary previously there was a gap of there of about 5mm. With this closed up it bought me about another 10mm of clearance in total. Now I'm happy, just hope the engineers are too when the time comes!

 

[peter mc]

the hard times in the shed are the ones you be most proud of .this will be a grate car when finished

[KatoKid]

Well all the firewall mounted clutch MC alternatives I looked out just won’t work. I actually only have 60mm clearance between the firewall and the rear of the cylinder head so the longest the MC could be is about 50mm to provide the 10mm clearance the engineers demand and as far as I can tell there is nothing on the market that is the ¾” bore that I need and is that short. The other issue is that the Z pedal delivers only a short 25mm stroke at the MC which isn’t enough

 

The under dash alternatives were either a bellcrank set up to turn it through 90 or 180 degrees or adapt something like the BMW set up on the side of the pedal box. I’ve done other conversions which were let down by excessive clutch pedal effort and or poor disengagement through lack of actuation so which ever solution I went with I’m determined to get this right and this means replicating the original BMW set up in regards to MC and slave cylinder sizes and stroke. The bellcrank route has potential for fitment, friction and geometry issues which aren’t attractive. I got master and slave cylinders from the wreckers in the UK so I know what I need to replicate.

 

The E36 pedal box has a very compact plastic MC and an elaborately shaped plastic pedal. The remote reservoir line runs through the firewall and is supplied from the brake master reservoir. The pressure line to the slave runs straight out the end of the MC and also through the firewall. The plastic MC is definitely useable but adapting the plastic pedal to the Z pedal box was not a realistic option and would not have worked asthetically.

 

I found an earlier E30 pedal box at the wreckers that had a much longer aluminium MC but with a conventional steel pedal with a separate lever to push the MC. The plastic pedal in the E36 is the same plane as the MC hence the fancy shape but in the E30 the MC is offset to allow the pedal to run over the side of the MC so it has the conventional look but needs the offset lever to push the MC. Some rough measurement convinced me that the E36 plastic MC would work with the Z pedal if I added the offset lever to push it with.

 

As I said, I was determined to get the correct piston stroke and pedal ratio to replicate the BMW set up. As they say pictures are worth a thousand words………

[KatoKid]

The Z pedal only delivers a short stroke with standard geometry but is also considerably longer than the BMW pedals so I could lengthen the MC lever to get more stroke and still get the same BMW pedal ratio of 5.7:1. It worked out really well…….. 3 x 5mm plate spacers to mount the MC and some more 5mm plate to make a lever for the pivot shaft and then some juggling to get the geometry correct through the travel of the piston (same principal as rocker arm to valve stem geometry) and I had it all mocked up. The sides of the 240Z pedal box are parallel with the pedal which makes it easier ands everything is square and pushing in the correct line. I used the shouldered bolt used to attach the lever to the MC push rod from the E30 as it was an exact fit for the E36 MC pushrod.

[NZeder]

Result perfect. Good job David

[KatoKid]

I was still short a bit of MC piston travel once I had it bolted in the car but this was fixed by making a lower clutch pedal stop on the firewall. The original is tallish as its job is to stop the clutch pedal from hitting the accelerator rod that runs behind it, I will be using a cable set up so don’t need this. I also had to remove the LH bracket for the accelerator rod as it was in line with where the pressure line comes out of the MC. Once I had done this I had full travel and same pedal ratio as the BMW set up so I’m confident it will work and feel as good as possible.

[KatoKid]

Thanks Mike.

 

All the BMW forums say they are a b1tch to bleed....can live with that if thats the worst!

[Sirpent]

Well done David !

 

If you hadn't come up with a solution I was going to suggest a Ford Probe Clutch cylinder, very short and totally encapsulated deriving it's fluid from a remote reservoir source, in the Probes case it's the Brake Master fluid reservoir.

 

But again your work is as impressive as ever, cant imagine what pleasures I will be faced with when I eventually start toiling with mine.

 

Cheers

 

John

[Wayne G]

The workmanship looks great! I hope it works out as planned. If not, did you look at an early urvan clutch master? The entire assembly is mounted under the dash in a fairly compact manner.

[NZeder]

The E36 clutch setup is a PITA to bleed - there is no return spring setup if I recall so when bleeding the clutch pedal goes to the floor and stay there.....very very non-zed like in comparison.

[KatoKid]

Wayne G

 

Yep, looked at lots of alternatives but all had too many compromises.

 

I had a similar set up like you mentioned from a Hiace van in my Mk I Cortina with BBC power.

[KatoKid]

In the BMW application the clutch MC is fed by a flexible line that runs through the firewall and connects to the brake MC reservoir for fluid supply. The reservoir hose clips into the top of the plastic clutch MC as does the pressure outlet line. I had the clip and hose for the reservoir but not the hard line or clip for the line that goes to the slave cylinder, as you can see from the pics there is nothing else (that I know of) like it so I had to get the hard line from a wrecker.

 

With it all mounted to the pedal box its a tight fit for the reservoir line underneath my mounting bracket but the rubber grommet where the reservoir line goes through the firewall is a perfect fit for the hole were the Datsun clutch MC normally is ....perfect. I will use a Commondore remote reservoir or something similar in the engine bay.

 

The hard line will run across to the passenger side of the car on the inside of the cabin and then join a flexible hose to the slave cylinder outside.

[KatoKid]

The shifter that came with the Getrag 6 speed from the UK is too short (distance from the back of the gearbox) so it wouldn't even reach the original hole in the tunnel, I want the interior to look stock and have the shifter in the original position so I found that a shifter from a E46 318i is the perfect length. The BMW shifters are remote mounted to the body using a rubber bush at the rear, there are different designs but the bush sizes are all the same. I chose an E30 bush and bracket as it was easiest to modify which entailed cutting off the original bracket adding a new section and drilling and tapping two holes. I kept this as high as possible in the tunnel so that when I add a short throw shifter (quick shift) later on I don't run into issues with the shifter hitting the tail shaft which is a common problem in BMW's.

 

Although the whole drivetrain is significantly offset to the drivers side the remote mounting made it possible to position the shifter right in the middle of the tunnel hole.

[KatoKid]

Last thing for the shifter was to fix the jagged hole in  the front of the tunnel opening. Being an early 240 it came with a 71A gearbox, somewhere in the past someone has fitted a 71B box and very roughly cut the hole at the front of the tunnel opening to accommodate the different shifter location. I will make an aluminium plate to join the BMW rubber shifter boot to the tunnel but wanted to repair the butchered opening beforehand.

[KatoKid]

I’ve pulled the engine from the car as my next priority is to get it running to confirm condition of the engine and also to prove to myself that the key, EWS II (security system) and ECU are “aligned” and the engine will actually start, if they aren’t I’m in a bit of strife!

 

As I’ve touched on before the later Evo E36 M3 uses a pretty trick semi dry sump set up that splits the sump into two levels and has a scavenge pump at the front of the sump which delivers oil to the lower rear sump reservoir. Unfortunately I cant use this set up as the sump design is too deep at the front and will interfere with the steering rack so I’m forced to use the earlier M3 sump with wings and baffles and standard M50 oil pump and pick up.

 

The front scavenge return line and pick up tube of the later M3 set up is secured by  two brackets mounted to #3 and #5 main bearing caps, these need to be removed and replaced with a single bracket on #5 main cap to suit the M50 pump and pick up.

 

I removed the main bolts and pulled the #3 and #5 caps to check out the bearings and main journals. I’ve always been a bit disillusioned with how dirty the engine is both externally and internally and suspected that the wrecker wasn’t honest with the mileage but was pleasantly surprised by how good the bearings looked, a bit of polishing in one area but otherwise looked very good. I’m sure the dirty engine exterior is due to the salted roads in the UK and I’m praying the dirty internals are due to short runs, cold temps, poor oil and or maintenance schedule. So everything went back together with new bracket on #5, M50 oil pump but with larger S50 pump drive gear, windage tray from the S50B30 (later B32 doesn’t use one due to the semi dry sump design) and the earlier M3 sump.

 

Plan is to build a test stand with a proper cooling system and exhaust so I can run the engine properly to get a feel for how good a nick its in. Wet and dry comp test and listening and observing will give me a pretty solid idea of how good or not it is.

If the engine comes up alright it will go back on the engine stand so I can remove all the corroded alloy parts for refurbishment and will replace front and rear main seals and most gaskets and paint it. I’ve already got a set of ARP rod bolts and will replace big end bearings at the same time, no point doing this now as if the engine needs serious work I’ve just wasted $160 worth of rod bolts.

 

 

[KatoKid]

Earlier B30 sump with ears and baffled.

[C.A.R.]

Bloody impressive Dave!

Keep it up

[KatoKid]

Got started on the engine test stand today.

 

A length of 50 x 50 x 2, 4 caster wheels and a couple of hours got the basic frame finished. Used the original M3 front crossmember and mounts cos I had them and it looked easier than any other way.

 

Now comes crunch time ..... I need to set up cooling system, gauges and control panel, fuel system and exhaust so I will be buying radiator that will be used in the actual car, same with gauges and fuel pump. Will jury rig a full exhaust system as I want to be able to hear any noises from the engine and particularly the problematic Vanos system.

[NZeder]

nice - good progress

[Sirpent]

David,

 

Every weekend I have but one wish, thats to win tatts, and the dream if I did, employ you lurch and Peter mac for 2 months to come work on my Zed while I tinker with the cosmetics.

 

The level of detail and preperation on your build is ultra impressive.

 

 

[KatoKid]

Thanks John, Mike, Lurch et all.

 

The kicker is that I really enjoy doing this....granted there are some things that are less enjoyable but the sense of satisfaction and knowing that you've done something to the best of your ability is what keeps us all going on our various projects.

 

I have to say that having the right tools makes a big difference as well. I'm sick of doing things the hard way as it just kills the motivation so if I need to buy something that will get used enough to justify the expense than I just go and do it.......within reason of course.

[peter mc]

nice now just hook that up to the engine dyno  looks good mate  ,

[Zedman240®]

You could also hook up a roostertail blender on the back of the trans to do something while testing....

 

Friggin' excellent....

 

 

 

 

 

edit* does the forum software replace "cee oh cee kay" with rooster?

[RB30X]

and the dream if I did, employ you lurch and Peter mac for 2 months to come work on my Zed while I tinker with the cosmetics.

 

I know they aren't very attractive men, but how much cosmetics would those two need in two months while working on your car?

 

Nice work on the engine stand mate. I always wanted to put an ls1 on one in my shed.

[KatoKid]

Haven't had a chance to even look at the Z in the last few weeks and so need to get cracking again.

 

I had to build a frame on my test stand to replicate the firewall mounting of the main engine harness that runs over the back of the cylinder head so decided to extend this and make it a dual purpose work table as well as somewhere to mount all the components.

 

The BMW design has a pretty cool nearly self contained main engine harness that includes the ECU, some relays, O2 sensors etc all this interfaces with the body via a single 25 pin connector, means they build one body loom for most of their models and each differnet engine just plugs in.

 

The other element is the security system which many have tried but no one has succeeded in bypassing. The security system called EWS II is part of the body but still sends and receives inputs through to the ECU via the the 25 pin plug called the X 20 connector. Basically the security system sends code between the EWS box and the key and ECU via a transmit/receive module. Each time the car is started it sends new code to and from each component. It is imperative that you have the "aligned" key, EWS and ECU from the same car otherwise the engine wont run. They can for differnet reasons become "unaligned" which is a major drama to fix as it entails taking the vehicle to a BMW dealer for them to re align the system. Imagine a 240Z plugged into the computer at a BMW dealer!!!!

 

Its taken a lot of work and effort on the interweb to understand the system and confirm the wiring on the factory diagrams which (for me ) are a nightmare to read. You should see the size and weight of the body harness...its massive. Ive had some great help from a guy on a BMW forum in the UK.

 

I've striped out the bits I need from the harness and am ready to start putting it all together.