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Alfaaa1
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Crank angel sensor pulley

Post by Alfaaa1 »

Hi to all,

I need some advice.

I am fitting a 3.2 24v Busso to my Alfetta GTV 4,(It's getting close to being completed :D )

I need to fit a crank angel sensor to the front of this engine.

Can you please confirm which crankshaft pulley I need ( Alfa Model) that fits the 3.2 . :?:

Thanks
Jim K
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Re: Crank angel sensor pulley

Post by Jim K »

Find a pulley from the 164 24v and the associated timing cover. You may have some trouble with the cover but it can be done. Alternatively, you can weld a couple of carefully-placed bosses on the 3.2 cover. Before putting everything together, check position of missing teeth on 3.2 flywheel at TDC and reposition toothed wheel on crank pulley accordingly -otherwise the engine will never start!

Jim K.
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Alfaaa1
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Re: Crank angel sensor pulley

Post by Alfaaa1 »

Thank you Jim,
I see if I can get one over here in Australia.

Regards
105gta.
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Re: Crank angel sensor pulley

Post by 105gta. »

Depending on what type of ecu you are running there are other options. You'll need the factory type (30-2) for a factory ecu. finding a 164 24v pulley and cover could be hard in Aus. If it's an aftermarket ecu you may only need three trigger points. (For each top dead centre) then the factory conveniently placed a hole in the bell housing (behind the l/h head) which lines up with the flywheel. Easy place to drill/tap and screw in three bolts for the sensor to read. Leaving you with the option of what ever front pulley/belt type that you already have or want to use.
Don't forget you'll have to balance the rotating assy after any pulley alterations. Front or rear. Especially as the 164 pulley is for a 3.0 not 3.2. (Different counter weight to suit different stroke)
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Re: Crank angel sensor pulley

Post by KevinR »

Just bolt aftermarket trigger wheel to front face off pulley . That's what most guys do here in UK and also in SA . I will find some pics . Very easy solution .
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Re: Crank angel sensor pulley

Post by Alfaaa1 »

105gta,

I like your set up with the fly wheel, :D
Would you photos or diagrams of bolt locations on the flywheel.

Kevin, it would be great if you attach some photos .
Would you have details were I can purchase the trigger wheel + the sensor.

Regards
KevinR
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Re: Crank angel sensor pulley

Post by KevinR »

I will take some pics on Monday of friends car with it on . I had my trigger wheels cut in SA few years ago . If you pm me in can get you price from guys in UK that do it . What ecu are you running ? As my ecu is aftermarket I used bmw pick up sensor when my 164 sensor broke ( became intermittent ) .
105gta.
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Re: Crank angel sensor pulley

Post by 105gta. »

Hi Alfaa1, as Kevin said there are aftermarket wheels available.
Regularly on eBay. Depends on the Ecu you plan to use.
I don't have photos but could take some for you. If needed. As for positioning the dowels/bolts. Just set the engine at tdc. On cyl 1 with a dial guage to be exact! Make a small plug/sleeve with OD the same size as hole in bell housing and ID of required drill size to centralize the drill bit and drill them through the plug/guide to depth needed. Wind engine over to tdc on cyl2 and do the same. Cyl 3 etc.. Will give you three holes at equal spacing on tdc of the 3 points required. I think from memory the hole is 19mm and the factory sensor is 18mm if you put a thin(1mm cross section 'O'ring on the sensor) it will self centralize in the hole or if you prefer make a thin sleeve. You have to file/grind a small area to mount the original bolt for the sensor to be held down. If you have the factory engine wiring harness for the engine the sensor wiring is already at the rear of the engine so you won't have to extend or alter the wiring to a new location.
Which ever way you go the air gap between the sensor and trigger points Is important. So each bolt then gets cut off/ground to the required height or make sure a front mounted trigger wheel is really centralized.
As a point to note.
Although I haven't heard of any issues with busso harmonic balancers. Ideally you would want to mount a front mounted sensor to the central/rigid part of the front pulley (engine side of pulley). Hence why Alfa used the flywheel on the later engines. Solid to crank! Other wise as the rubber mounted section/outer ring does its thing (read as wobble/ fluctuate) in a rotating direction both advancing and retarding. Your ignition timing will fluctuate. Maybe even enough for the sensor to lose its signal under certain conditions due to varying air gap.
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Re: Crank angel sensor pulley

Post by Alfaaa1 »

Hi 105gta,

This great info. :D

I do have the flywheel housing with the crank angle sensor hole.

Would you know what size the pins / bolts are that were used in the 3 locations.

Which model Alfa was this setup originally used on.

Thanks again 105gta for this info. :D
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Re: Crank angel sensor pulley

Post by 105gta. »

I'm not sure if Alfa used this particular hole for crank sensing maybe on some euro model. Or for some reason on the production line, but it's machined in every bell housing I have ever seen. They obviously spent the time and money to do this for some reason but it does give us a good place to create a crank sensor. The factory sensor on later engine like yours was mounted on the sump and the 36-2 trigger wheel was mchined into the back face of the flywheel. Which is not used in rear wheel drive setup like yours. Most after market Ecu's are happy if you use an 8mm bolt size. Find some bolts that have say 12-15mm of thread than a straight shank. Screw them in till the thread runs out like a stud with some loctite and cut them off at the length you want.
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Re: Crank angel sensor pulley

Post by Alfaaa1 »

Thank you 105gta for the info, :D

Just confirming , The ECU will work with only the 3 pins magnetic field sensor readings.

I will try the 3 pin setup.

If you can attach photos it would be good.

Thankyou again :D

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Re: Crank angel sensor pulley

Post by 105gta. »

It depends on what Ecu you are using! A factory Ecu will not work with three pins but most aftermarket will like Motec, Autronic etc... The factory motronic needs 36-2 sensor wheel.
Confirm what you have and need before modifying anything.
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Re: Crank angel sensor pulley

Post by Alfaaa1 »

It will be an aftermarket one, Most likely a Motec.

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Re: Crank angel sensor pulley

Post by Alfaaa1 »

Hi Kevin R, Would you have any photo's.

Regards :D
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Re: Crank angel sensor pulley

Post by KevinR »

Hi , sorry for delay . The pics I had were on my iPad which for some strange reason slid off the roof of the Giulietta . After hearing slide down the back window while accerating away from work I convinced myself that I could have done something so stupid to leave it on the roof hence I continued home .
Long and the short of it I will ask my mate to take some pics of the trigger wheel again .
I did embarrassingly report it missing possibly of the roof of car and loan behold it was handed in to the Chichester police in a thousand pieces :D . I'm sure they were cursing immigrants when I went to collect it 8)
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