Help! M30B32 1.3 Conversion, Mounting Crank Trigger?

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Joey28
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Help! M30B32 1.3 Conversion, Mounting Crank Trigger?

Post by Joey28 »

I'm swapping my 1983 533i M30B32 over to Motronic 1.3, and got all donor parts from an '89 635Csi. My problem is I can't seem to get the B35's crank trigger bracket to mount up the same way as it was on the M30B35 donor motor. Seems to hit the AC mounting bracket. Do I need to change that out too?
I can get the trigger mounted with the OLD MB32 diagnostic sensor mounting bracket, but that's not the "right" way and I worry it's not at the correct position relative to the crank rotation either.
I've read the whole B35 swap FAQ and have it on-screen out here in my garage. Searched "crank position sensor in the forum too- Am I missing something? Is early M30B32 special somehow?
Any help would be greatly appreciated!
Joey28
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Re: Help! M30B32 1.3 Conversion, Mounting Crank Trigger?

Post by Joey28 »

I ended up figuring this one out myself with some help from Ahab. I have an '83 M30B32, with the old style oscillating plate AC compressor and mounting bracket, which gets in the way of the Motronic 1.3 crank sensor bracket. I tried using the old original 1.0 TDC sensor bracket, but realized it's at the wrong clock position. So I ended up having to carefully grind a small notch in the AC bracket. I also had to massage the upper adjusting arm to clear the top of the 1.3 sensor and bracket.
tschultz
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Re: Help! M30B32 1.3 Conversion, Mounting Crank Trigger?

Post by tschultz »

I did the same thing on a conversion of an '81 635 a few years back. How do you like the 1.3 swap on your 633?
Joey28
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Re: Help! M30B32 1.3 Conversion, Mounting Crank Trigger?

Post by Joey28 »

tschultz wrote: May 17, 2022 9:03 AM I did the same thing on a conversion of an '81 635 a few years back. How do you like the 1.3 swap on your 633?
I've got a 533, but I'm still not done yet. I'll let you know though! I'm hoping it will be worth it.
thrty8street
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Re: Help! M30B32 1.3 Conversion, Mounting Crank Trigger?

Post by thrty8street »

Joey28 wrote: May 17, 2022 6:02 PM
tschultz wrote: May 17, 2022 9:03 AM I did the same thing on a conversion of an '81 635 a few years back. How do you like the 1.3 swap on your 633?
I've got a 533, but I'm still not done yet. I'll let you know though! I'm hoping it will be worth it.
Was the 1.3 swap worth it on your 533i? I am hoping to tackle this next after finishing my brake and suspension overhaul.
Joey28
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Re: Help! M30B32 1.3 Conversion, Mounting Crank Trigger?

Post by Joey28 »

Hey. I'm happy with it. Not a big power improvement or anything, but somewhat better drivability. I used all parts from a lucky-find donor 635Csi at a U-pull-it. Got rid of the crappy old leaking cold start valve (was a real problem w the old M1.0; wouldn't start reliably), now it starts every time, regardless. Was able to use new style injectors, and most of all can convert to MAF. I'm going to do the conversion from SSquid as soon as I have time. This car is my DD- it was considered a great small family car back in the day and still can be- but it has to run without issue, so I did everything right: ran the CEL to an empty spot on my dash cluster. Placed the O2 sensor further downstream where it is in the later cars that run 1.3 too, made sure the AC switch is correct, etc. But I'm looking forward to doing the MAF. I had a Miller in it but got tired of feeding my stock, low-compression M30 premium fuel. SSquid lets you just run your otherwise stock tune on regular fuel. I wrapped everything in the good Tesa harness tape so it looks good too and should last.
I guess it ultimately depends on your goals, but for a DD that you want to keep running a little better and maybe modernize a little, I'd say do it.
Joey28
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Re: Help! M30B32 1.3 Conversion, Mounting Crank Trigger?

Post by Joey28 »

thrty8street wrote: Jul 02, 2023 2:25 PM
Joey28 wrote: May 17, 2022 6:02 PM
I've got a 533, but I'm still not done yet. I'll let you know though! I'm hoping it will be worth it.
Was the 1.3 swap worth it on your 533i? I am hoping to tackle this next after finishing my brake and suspension overhaul.
By the way, I did a full E34 brake swap on mine from a 535i (E32 stuff is thicker rotors but same diameter, but also heavier- beyond being of any real use in my stock E28 due to extra unsprung weight IMO) but kept the OEM MC and have never looked back. These are the best brakes I've had in an old car, and behind Style 29 wheels they look good too. Part of the reason I still drive my 40 year-old, no-ABS, no-Trac control E28 whenever I can, even on long trips, when I have a 750il and a E83:-)
thrty8street
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Re: Help! M30B32 1.3 Conversion, Mounting Crank Trigger?

Post by thrty8street »

Joey28 wrote: Jul 02, 2023 4:02 PM Hey. I'm happy with it. Not a big power improvement or anything, but somewhat better drivability. I used all parts from a lucky-find donor 635Csi at a U-pull-it. Got rid of the crappy old leaking cold start valve (was a real problem w the old M1.0; wouldn't start reliably), now it starts every time, regardless. Was able to use new style injectors, and most of all can convert to MAF. I'm going to do the conversion from SSquid as soon as I have time. This car is my DD- it was considered a great small family car back in the day and still can be- but it has to run without issue, so I did everything right: ran the CEL to an empty spot on my dash cluster. Placed the O2 sensor further downstream where it is in the later cars that run 1.3 too, made sure the AC switch is correct, etc. But I'm looking forward to doing the MAF. I had a Miller in it but got tired of feeding my stock, low-compression M30 premium fuel. SSquid lets you just run your otherwise stock tune on regular fuel. I wrapped everything in the good Tesa harness tape so it looks good too and should last.
I guess it ultimately depends on your goals, but for a DD that you want to keep running a little better and maybe modernize a little, I'd say do it.
Thanks for the feedback! Which injectors did you use? Are these high impedance injectors?
SparkJR
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Re: Help! M30B32 1.3 Conversion, Mounting Crank Trigger?

Post by SparkJR »

Not OP, but also daily a 533i with 1.3.
As he said though, not a huge power improvement on its own, but more chip options available for the ecu, more smooth and reliable, adapts slightly according to your driving style, etc. The slightly higher compression of the b32 seems to like it.

As far as injectors, I’m running 19lb (yellow body) injectors from a 90’s/early 2000’s mustang. Had them rebuilt and flow/electrical tested.

Also running some no name, “clone” chip in the ecu. Thing is noticeably more responsive, and will be even more so once I do the MAF conversion. A good stopgap until then is adjusting the AFM wiper to a spot on the post where the electrical contact isn’t as worn, reduces acceleration hiccups significantly.

TL;DR, definitely worth it for the b32 with some additional mods, wakes the thing up quite a bit!
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