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Discussion Starter #1
Hi guy's,
I am after some advice,

I have an 851 engine, although at 888cc capacity, I plan to use this in my project build. I have a 1098 loom, clocks and ecu.

I have noticed that the pickup for the 1098 timing sensor has a 3 wire plug, and the 851 has 2. plus another sensor pickup off the flywheel.

After taking the 851 cover off, I can see the sensor "sees" a tab for timing reference on the gear (which are helical). The timing for the 1098 "sees" a gap in the teeth.

I have a later 2 phase cover, susp 748 etc. that has the timing hole further out to read the gap in the teeth from a gear that has the 2 teeth ground back.

On the three different timing gears, the pickup tabs or gaps are in different positions, when the TDC marker dots are aligned with the crank gear.

My questions are,

1, Can I fit the later 2 phase cover with the corresponding 3 wire senor (2 mounting screws) along with the 748 etc timing gears?

2, Will I need to fit a 999 sensor and bore out the cover to fit the diameter of the bigger sensor. Again with 748 gears?

3, Can the ecu be reprogrammed to see that the 748 missing teeth are in a different place to the 1098 teeth when the crank is at TDC?

I am sure there will be more questions, or indeed other factors/scenarios that I have not posted.

Cheers,
Mick
 

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i guess why is a redundant question.

firstly, clarification of alternator description. the number of phases is dependant on the number of pairs of wires available. 2 wires means 1 pair - 1 + 2, single phase. 3 wires means 3 pairs - 1 + 2, 1 + 3, 2 + 3, 3 phase.

1/ someone on the ss page did a 3 phase into single phase motor conversion - some custom machining to make the 3 phase alt rotor fit onto the single phase flywheel hub was the main part of it. wasn't that big of a job if you're handy in that way from memory. that's really all it is - making the 3 phase rotor fit. with no flywheel sensor to worry about, that'd be all you'd need to do. the cover just bolts on.

2/ the third wire on the sensor is a shielding earth. i think the later single bolt ones have a bit more base resistance than the earlier two bolt one, but apart from that they'd be interchangeable. certainly i would expect to be able to plug a late pick up engine into an early loom and ecu bike and have it work as expected sort of thing. some of the models, don't recall which now, had a spacer block to mount them. but now that i do think about it, that'd only make sense on the last of the 996sps where they were mating the early pick ups to the later 3 phase alt cover. ? confusing myself now, possibly of no relevance here.

3/ should be able to, never gone looking myself. the thing is that alternator covers and gears will probably match though - the ecu may be the same. i have thought about checking the orientation, but never when i have a cover off an engine. i would expect that the cut outs in the gears will be in the same place relative to the pick up with the marks lined up. could be wrong, as i say never looked. i recall someone who did an 1100 monster where they replaced the siemens gear (2 cut outs) with a marelli single cut out, but they used a gear from the wrong pick up position model and they had a shitload of trouble with it until they worked out that the phasing was off due to the gear cut out not being right for the location. so if you use a 748 alt cover, use 748 timing gears is my best guess.

now that i think about it, i think i've had this conversation with aran from walt siegl's and aran said the cut out relative to pick up is the same for the given locations/combinations. i think.

4/ what crank are you using? the 6 spline flywheel hub cranks have a smaller diameter where the timing gears fit compared to the 16 spline. i was going to do something like this years ago and had pete smith make me a spacer that i ended up selling to phil costin who then sold all his 851/888 stuff to someone in the uk. so if you have a pre 91 maybe crank you'll need to think about that and a very tall locating key.
 

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Discussion Starter #5
Thanks for your reply.

On inspection, the alternator has two wires, and is mounted with the 2 screws on the outside of the coils.

The alternator cover has the sensor mounting position further in towards the centre of the timing gear, due to the tab on the timing gear being further in.

The crank/flywheel is the later 16 spline version.

All in all, if I have it correct, I can convert to a 3 phase (I have a spare cover) fit the later 996 etc timing gears, flywheel, starter gear, sprag and sensor.

I need this to work with the 1098 Loom, dash and wiring harness.
 

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so all you need to do is make it single pick up?

the 95 - 98 4v and st2 engines with the 1.6m ecu are single pick up and single phase alt. not all are 3 wire pick ups, but i think 97 and 98 are (?). you could use an alt cover from one of them with the appropriate timing gears and it would then be single pick up and that is all you would need to change as they are a 3 wire sensor. then you can remove the bolt on flywheel weight that for the p7 has 4 triggers, as it now serves no purpose.

or you can make it 3 phase alt as well. i thought 3 phase alt was part of the change you had planned. it's more work, as the ss thread shows.

https://www.ebay.com.au/itm/Ducati-Engine-Cover-Alternator-ST2-Also-916-044/173635144497?hash=item286d760b31:g:6zsAAOSwxPNb5~vc&LH_ItemCondition=4

https://www.ebay.com.au/itm/Ducati-ST2-ST4-748-916-crank-position-sensor-Magneti-Marelli-SEN813/372652128562?hash=item56c3cc3932:g:d~gAAOSwpHtcszm3&frcectupt=true
 

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Discussion Starter #9
I've already done the ST4s engine an 851 frame...
IMG_0200.JPG


On this project, the 1098 loom and ECU is to hopefully save weight. The 851 loom consists of 3 parts, plus huge ECU, plus ignition control units and relays. Most of the 1098 loom will be stripped back as I hope to run on a " Daytime MOT. IE.. no lights or indicators..
 

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Discussion Starter #10
PS... The engine from the bike above is the one I'm using in the new project. It's an 888 with flowed heads and SP3 cams.. The forks are FG 9050 and I already had them. The idea was to use as many spares accumulated over the years and build a bike for minimal outlay..
(y)
 
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