M60B30 stroking

[Frank87]

I want to do a full engine rebuild. Reasons are:
- Rest of the car incl. gearbox has been done
- Car will be resprayed completely. Removing the engine also allows me to recondition the engine bay

The car has an M60B30 engine. I have a spare engine so I can keep driving untill its done.

A friend of mine totalled his E39 540/6 and bought a cheap 535 to put the 540/6 driveline in. I can get that M62 3.5 cheap. Its a vanos engine.

The M60B30 and M62B35 share the same bore, only the stroke differs. I am thinking of dropping in the M62 crankshaft, conrods and perhaps pistons too (or reworked pistons if needed). I would be using all other parts from the B30 to keep everything easy.

In short, you would get an M60B35 with 84 x 78.9 running on M60B30 heads. If this is all direct fit stuff, I will put the engine in the car at the end of the year and go for a custom exhaust system. After that, I'll let a specialist do a full remap on the engine.

Question: Will I be able to drop in the shaft + conrods?

Second part will be the air intake system. I will have all M60B30 parts, M62B35 parts and I also have all M60B40 parts. So, starting at the airbox, what combination do I want to use?

Airbox + MAF + Hose + throttlebody: M60B30, M62B35 or M60B40 parts.
Note: Can't use 3.5 throttle body as its electric

Intake manifold: M60B30, M62B35 or M60B40.


And no, I won't go for a B40 swap. That would also mean I have to put in the 5HP30 gearbox (which I would then want to rebuild). A 4.0 block has value due to its high "E30 project" potential. Doing a "M60B35" build would cost me up to 1.000 euros. Doing a 4.0+5HP30 swap would go to 3.000.

I do not worry about the 5HP18 gearbox. I will handle that torque. Reason for that is that it can take 310Nm and that was based on the earlier model with 3 or 4 clutches. My 5HP18 model already has the higher line pressure and 4 to 5 clutches.

If you guys have any knowledge on this, let me know. I will be stripping the B30 soon so pics will follow.

[Frank87]

Update:

Today I went to a machineshop recommended by my indy. They said I can probably drop the crank and conrods right in. Depending on the pistons, they may have to rework them a bit to make sure TDC is still the same. They said that as far as they can remember, BMW used the same liner height in M60 and M62 engines (but they were not 100% sure). All Mahle liners they could order for M60 and M62 engines also had the same height.

So one way or another, drop-in or with slight reworking, I think I can get that B35 stroke.


In addition, I was planning to overhaul another 5HP18 box as I could then put my current M60B30+Overhauled 5HP18 on a pallet in stock. It could one day find its way to an E38 or another E34.
However, to ensure the 5HP18 will easily take that 320-340Nm this M60B35 will put out, I plan on strengthening the clutches. I will do so by adding 1 clutchplate and 1 steelplate per clutch pack. I will then use the thinnest snap ring ZF has to offer. After measuring end clearence, I will, if nessecary, machine the end plate and all steel plates a bit to compensate for the increased clutch pack height. I think I can get away with this.

This would lead to a 5HP18 (which already went from 3 or 4 to 4 or 5) that has 5 or 6 clutches per pack. Line pressure will stay the same as pressurework is risky. Since I will ensure the end clearance is still 100% within ZF factory limits, the valve body and AGS would still be able to correctly apply each pack.

Can anyone comment on this idea?

[Frank87]

Did some more research and talked to some more people.

Removing material from the steels to add another clutch carries the risk of overheating clutch packs. Extra coolers won't help as this heat appears for a very short duration. My gearbox specialist does not know what the minimum required thickness of the steels are. He said the only reliable way would be to increase the pressure a little bit. This would maybe up the 310 limit to 330/340. He was not sure if the 4-5 clutch variant of the 5HP18 could take more power but the theory behind adding clutches (if the steels allow it) is correct.

Since a M60B35 with performance exhaust, high flow cats and modified intake (whatever way I go on that intake) can probably do 330-340Nm, the 5HP18 is a risk factor. A reliable and known path would be to fit a 5HP30 + wiring from a 540 or 740. Sockets may be a bit different but the wiring diagrams would show me exactly what to solder.

However, if I want to fit another type of box, I want a 6HP26 (600Nm max.). Funny thing is both the specialist and I proposed just that at the exact same time. I said the risk with a box from an OBDII car is that it won't run properly but the specialist can write custom software that would run on the signals my 5HP18 uses as well.

This makes the 3.5 project obsolete as a M60B30 with a 6HP26 would already have better performance figures. The 6HP26 is lighter and has a shorter 1st gear with a similar ratio build up towards the 0.69 6th gear. That 0.69 6th gear is longer than the 0.71 I have now so that 2.x% difference can be compensated with another differential or smaller tires.

In short, I would gain acceleration.. get quicker shift times and keep highway cruising RPM. In addition, this gives me engine tuning space up to 600Nm (lets say 550 to be safe).

I will talk with my guy some more and think this out. We think we can make it work so I will probably go for the 6HP26 path, get that to work properly and then see what I would want with my engine.


More soon.

[632 Regal]

I

The M60B30 and M62B35 share the same bore, only the stroke differs. I am thinking of dropping in the M62 crankshaft, conrods and perhaps pistons too (or reworked pistons if needed). I would be using all other parts from the B30 to keep everything easy.

Question: Will I be able to drop in the shaft + conrods?

You would need to drop the pistons also because of the piston pin height and conecting rod variences. As a matched assembly you should not need any rework on the pistons, plug n play.

[632 Regal]

Airbox + MAF + Hose + throttlebody: M60B30, M62B35 or M60B40 parts.

Intake manifold: M60B30, M62B35 or M60B40.


I would use the 4.0 airbox and the rest would be the 3.0 componants. Reason being this will eliminate any low end power issues while still being adequite for decent top end power. No computer re-mapping, another plug n play operation. The inlet on the 3.0 airbox is extreamly small and any changes I would do on my 530 would be the box (where it goes through the bottom to get the cold air). This will not affect any low rpm but allow more airflow at higher rpm's.

[632 Regal]

And no, I won't go for a B40 swap. That would also mean I have to put in the 5HP30 gearbox (which I would then want to rebuild).


Both blocks have the same transmission bolt pattern. Swapping a 4.0 in will not require the 5HP30 as the 5HP18 will bolt right up with no other changes needed.

[genphreak]

A 4.0 block has value due to its high "E30 project" potential. Doing a "M60B35" build would cost me up to 1.000 euros. Doing a 4.0+5HP30 swap would go to 3.000.

I agree with you I would hate to install a B40 and thus a 5HP30, that trans weighs a tonne!

Why not get a price on a M62 and 6/7 speed trans (no need to rebuild, huge gains in economy, etc.)? There are many from X5 that all have very short lifespan because they are so hard to look after. Places like Schmiedmann have them cheap, but in the US (you are US, right?) breakers can do a whole package far cheaper- you just have to call and negotiate something with them.

Perhaps the trans on a M62B44 or 4.7 VANOS e39/e60/X5 engines are lighter than M60B40, assuming you can't go stick on your budget. Even if they are the same, either of these would make one sweetly quick and economical e34!

[genphreak]

Did some more research and talked to some more people... I will talk with my guy some more and think this out. We think we can make it work so I will probably go for the 6HP26 path, get that to work properly and then see what I would want with my engine. More soon.

Subscribed.

New info on transplanting more modern auto transmissions into e34 will be a boon for the community worldwide. Please do share so others may build on your success.

I can't add much in this area, but you might like to look at the ZF trannies used in other vehicles (BMW LandRover, Range Rover) and Volvo, Mercedes, etc. ZF may have added more clutch packs to deal with the weight of these chassis, let alone the higher engine outputs.

We had a series I Discovery (1991) with ZF LT77 5-speed manual gearbox, but the auto version was a 4HP22EH IIRC. That was the Land Rover 3.5 V8 petrol (Buick block), but the later ones (stroked to 3.9) had updated ZF drivelines. The Diesels were BMW 5 cylinder 2.5 turbo engine from day dot which may well have been all ZF too.

They eventually moved the Petrol models to BMW engines with Motronic (M62) in Series III Discovery.

[Frank87]

Thanks for the advice gentlemen. Research is going fast on this project. The 6HP26/28 is about 5cm shorter than the 5HP18. I can compensate that by using a custom made spacer on the flex disc with the same shape. This takes away the need to use custom driveshaft stuff. I consider space to be solved. It still means I will have to manufacture a custom gearbox support that uses the existing bolt holes. There are alot of holes tapped down there so I can make a strong and sturdy unit bolted up to 4 or 6 holes.

In addition, I did some "photo research" on these boxes. Here's the result:

Picture 1: 5HP18 V8, max 310Nm
http://img.photobucket.com/albums/v432/PMAngelEyes/5HP1820Housing_zpswih3wpi7.jpg




Picture 2: 6HP32 (32!) V8 housing, max 750Nm +/- 5cm shorter (zf source)
http://img.photobucket.com/albums/v432/PMAngelEyes/6HP32%20Housing_zpsfax39zmf.png



Picture 3: 8HP75 V8 housing, max 750Nm. No size data known
http://img.photobucket.com/albums/v432/PMAngelEyes/8HP%20pic_zpsxxdpdn9d.jpg


I can definately fit a 6HP26,28 or 32. The 26 can already take 600Nm which is well over the 5HP30 limit. Ultimately, I would put in an M62B44 non-vanos retrofitted with the double chain layout from the M60 and run that on M60 wiring. Some ZF docs showed that the 6HP uses similar variables when compared to the 5HP software. I will not be doing ANY software work myself. I have someone for that now. As I won't go higher than 4.4, the 6HP26 will do just fine. That 4.4 non-vanos at maximum "regular tune" (intake + exhaust + remap) will never reach 500Nm.

The 6HP26 can be improved for better shifting by adding upgraded seals (that are used on the 28). Since the 6HP26 are becoming cheap here in Europe, I will probably go for the 6HP26. Another reason is that early versions were delivered with the classic steptronic where the lever is manually operated and controls the electric box on the gearbox. I can retrofit steptronic parts from an E38 (this has been done before!) and combine that with a steptronic 6HP26. The later versions use the hypermodern full electric lever. That I do NOT want.

To ensure I get the optimum result from the air flow, I will do a dyno on my bone stock 530iA with all B30 intake stuff and one with all B40 intake stuff. This takes away any guesses and theories.

So in sum, I will be:
- Rebuilding an M60B30 and drop in M62B35 internals
- Do a precision measurement in 2 weeks on a friends V8 6HP26 car
- Use the measurements to decide what I would have to space at the flex disc
- Use the measurements to fabricate a custom box mount that uses plenty of tapped holes
- Find an early 6HP26 with 90' style steptronic and overhaul it. I will fit updated components

I have people who will:
- Decide how to keep my current torque converter (has similar dimensions) or how to get a 6HP26 V8 torque converter properly seated
- Decide how to reprogram or write transsoftware to use the signals the E34 gives. The 6HP will probably act as a 5HP regarding adaption and lose SOME of its functionality but thats ok.

I am still in doubt if I will remap that M60 3.5 or not. Will search some more info.

I also did some research on upgrading the internals to the absolute limits. 'Muricans use this box in Fords and call it the 6rxx series. For these boxes, custom clutches and clutch pack increases are available. However, my specialist told me that if you remove materials from your steels, the box can overheat more easy and no cooler can compensate the instantaneous heat shifting can generate. For that reason, I will keep the box itself bone stock other than ZF upgrades.

The mechatronic will be modified by my transmission specialist. I will talk with him in detail how I want this. I will probably go for a very smooth D mode while wanting the absolute max in the S mode. You may think BMW already does that but this is not the case. A custom tune can make the box super smooth in D but switch to totally different adaptations, pressure modulation and tolerances when switched to S.

I will have a long evening chat with my specialist next week as he is interested in this project as well.

[Frank87]

To show you guys why I want this, you can see the gear ratio graph here.
5HP setup (RED) uses standard 3.15 diff + 205/60/16
6HP setup (BLUE) uses 3.23 diff from a touring and 205/55/16


http://img.photobucket.com/albums/v432/PMAngelEyes/5HP%20vs%206HP_zpsoddewfz7.png


My goal is to keep final gears identical so highway cruising stays exactly the way it is now. Already, the car does laughable RPM at 130km/h.. about 2500 rpm. I want to keep it that way.

When we look at acceleration, the 6HP will give me a clear edge. Its gears are shorter but when you look at the distances between the gears, the 6HP follows up very nice and equally builds towards that 6th gear.
The 5HP has a steady jump from 1->2->3 but takes a bigger jump to 4 and from 4 to 5. Those gaps will be closed. To do this professionally, I will have to guess what torque/RPM curve the 3.5 with 3.0 cams and certain intake will get me. Without any knowledge on that, I can't say anything about the results. However, I can also reverse engineer the desired torque/RPM curve by showing the mapper what gear ratio's I will have. He will then be able to maximize the result of the mapping.

To reach all this, I will have to slot in a 3.23 and go to 55 height instead of 60. Easy as 205/55/16 is a cheap regular size.

In addition, I will add the 5HP30 mentality to this box by telling the software guy to program a take-off in 2 when using D mode. This will give me a steady ride instead of that sporty first gear. My current 1st gear is already pretty low. In S mode, I want full pressure and all 6. The extra power I get from the 3.5 would make that take-off driveable and comfortable.

[632 Regal]

Okay I see you are going above and beyond the standards. I have the '95 530 with the weak engine, the '94 530 I had could have been the 4.0 just because it was a freight trian. Was a nikasil replaced engine long ago.


I also did some research on upgrading the internals to the absolute limits. 'Muricans use this box in Fords and call it the 6rxx series. For these boxes, custom clutches and clutch pack increases are available. However, my specialist told me that if you remove materials from your steels, the box can overheat more easy and no cooler can compensate the instantaneous heat shifting can generate. For that reason, I will keep the box itself bone stock other than ZF upgrades

Keep an extra beefed trans in stock. THe 5HP 18 is pretty stout since the last one held the power with no issues, had to be at least 75 HP. more than this stock material. It seriously was a killer on the freeway. I am planning on selling this to get another 540 5 or 6 speed E34. Auto box is ok... more 'head room'.

[632 Regal]

Although completely irrelivent I sport the 3:64 rear gear because I am in a mountainous region.

[genphreak]

To show you guys why I want this, you can see the gear ratio graph here.
5HP setup (RED) uses standard 3.15 diff + 205/60/16
6HP setup (BLUE) uses 3.23 diff from a touring and 205/55/16

My goal is to keep final gears identical so highway cruising stays exactly the way it is now. Already, the car does laughable RPM at 130km/h.. about 2500 rpm. I want to keep it that way.

In addition, I will add the 5HP30 mentality to this box by telling the software guy to program a take-off in 2 when using D mode. This will give me a steady ride instead of that sporty first gear. My current 1st gear is already pretty low. In S mode, I want full pressure and all 6. The extra power I get from the 3.5 would make that take-off driveable and comfortable.

Thanks for posting good details and keeping us updated. I am very interested in your progress.

Sharing this makes what you are doing possible for some rather than none, and I'd hope that others will be able to build on your work with other models. This kind of work is normally far too complex for enthusiasts, and also alone trans specialists that have to charge for their time. In fact, it is so rare that I can see you and your partners pioneering the possibility of upgrading worn transmissions with newer units and extending the life of cars that would otherwise be scrapped. Apart from the uncloaking the technical challenge that exists over this at present, reducing unnecessary waste is commendable and good work, very!

Obviously it would be really great if you would share your software with the community too, as few are motivated to pay a lot to keep these cars on the road these days, making the commercial aspect of doing this on old models makes sustaining the effort marginal.

Like most of us, I wish I could share more. However the paragraph below may help you understand the philosophy behind the ratios the factory used in e34s, if not e36s and others, if you do not already. I know that to many, ratios are a science and the variation between models and markets is complex. Similarly cloudy to fitting auto transmissions from different years! However from my knowledge here in Australia where freeway speed limits are typically 110km/h (a few 90 and 130 but predominantly 110):

3.23 is stock ratio for standard gearbox (5 speed manual) e34s. Auto boxes (5HP18) are 3.91:1 for M20B25, M30B35 & M50B25 6 cylinders and 3.07:1 for the 'economical' V8 M60B30. 5HP30 (M60B40 V8) uses 2.93:1 as well as the different heavier transmission. A stick 540 (6 speed) shares the same 2.93 final drive as the auto. The reason I say this is that it illustrates a difference in thinking at the the factory- for 6 cylinder cars they use taller final drive ratios in the autos, but in the V8s they gearing is identical. No doubt the ratios in the US are different, but the philosophy will be the same, that is that the gearing in the auto transmissions used in 6 cylinders and the V8s is vastly different.