Technical data on the engine?

Beyond the displacement and manufacturing town, is there a model number or outside source of technical data about this engine?

• knock sensor? (NOTE: found one reference to 11.6 to 1 compression ratio, definitely premium.)
• muffler back-pressure relief valve?

Wiki reports "the same 647 cc two-cylinder engine used in the BMW C650 GT maxi-scooter." I was able to find the repair and parts for the maxi-scooter: http://www.maxbmwmotorcycles.com/fiche/DiagramsMain.aspx?rnd=1527414&vid=54688

Also this summary of the BMW C650 series: http://www.scooterforum.se/pic/bmw/C-650GT_teknik.pdf

However, it usually works best if we can find the i3-REX version for the engine and i3 systems.

Thanks,
Bob Wilson

Just found the BMW technical information site. For $250, I'll have 30 days to see what is available.

https://www.bmwtechinfo.com/

Bob Wilson

Here's the technical training PDF of the W20 (REx) engine. Maybe it has what you're looking for?

websterize said:

Here's the technical training PDF of the W20 (REx) engine. Maybe it has what you're looking for?

Click to expand...

Perfect! So many questions answered in that document. <GRINS>

Bob Wilson

There's also http://www.realoem.com/bmw/enUS/partgrp?id=1Z43-USA-02-2016-I01-BMW_i-i3_Rex&mg=11 if you want an exploded BOM

I used a $30, day pass to look up some details about the fuel tank. The https://www.bmwtechinfo.com confirmed some generic details but omitted specific metrics:

• Connectors and pins - confirmed, and color codes. I'd ohmed them out, so I had some static values.
• Pin order - no luck finding the pin order so I know where to find pins 1 & 4 are but have to inspect the car to determine which is on the top or bottom row. Static measurement show 1 ohm to the motor and with a small power supply, 6.7V, 1A, or ~6.7 ohms. I'll use a stronger power supply to determine polarity and measure the empty tank electrical load. A 20A rated relay enables the power to the fuel pump motor.
• fuel level resistance - confirmed and measured it at ~1k on empty. I'll have to measure the full tank resistance in the car to know the range. The levels and resistance values are not listed in TIS.
• tank pressure and temperature - its use is not described but we know it is a pressurized tank and protected from opening until normalized. That explains the pressure sensor but the temperature sensor? Perhaps for the fuel injection, engine controller.
• fuel line pressure - how to measure it is covered but the value is embedded in the specialized instrument, not the TIS.

I am used to dealing with Toyota Prius maintenance manuals which are better about showing the connectors, pin location, and wire color code. Toyota also shows measurement limits without insisting they are found on a custom, manufacturer tool or meter. Toyota does have custom tools but not to document the measurement range(s). As for the tank temperature, it still has me scratching my head.

I tried to find the part number for the 'frunk' but had no luck. I found the instructions on how to take it out and put it back in but curiously, the actual part name and number was not in that procedure. I had planned to take it out anyway to 'blue print' it and also access the tank connectors.

FYI, I used a Macintosh with Safari browser. I've got screen shots of important areas and a printed copy of a repair procedure. More information than I had before, TIS seems light-weight and calling out for manufacturer tools instead of publishing the values defeats use of generic tools.

Bob Wilson

While I don't necessarily agree, why would BMW disclose every detail to anyone without them paying for the privilege? Course, how much that's worth is also debatable, but they are a business. As is true with most manufacturers, they much prefer you utilize factory authorized service facilities verses independents. Those independents(and DIY'ers) can get access to the same info and tools, if they deem it worthwhile, but at a cost.

As vehicles get more and more expensive and complicated...the land of the DIY'er trying to fix or maintain them is getting harder and harder.

No problem Jim. Just as BMW won't mind my TIS product review. For the Prius, the Toyota's TIS and maintenance manuals are more useful.

When I don't find (or can't buy) the information I want, I get the parts and 'blue print' them myself.

Bob Wilson