free hit
counters
Starter ring gear question. - Engine & Ancilliaries/Gearbox - The Lotus Forums Jump to content
Multistrada

Starter ring gear question.

Recommended Posts

I'm thinking about using the starter ring gear as a crank signal for an efi setup. This would use the ring gear like a trigger wheel but with the missing tooth being a single lobe mounted to one of the cams. Hitachi had this setup on early 90s Audis. I really like the idea of not having to mount a trigger wheel to the crank pulley.

The questions I have are:

How many teeth are on the ring gear? If it's an odd number this idea pretty much stops here.

Second, is there a location on the bell housing where it would be reasonable to mount a hall sensor? This should be easy since I'd only need to drill and tap a 12 mm hole. Preferably somewhere accessible without pulling the engine.

Finally, what is the spacing between the teeth?

If anyone with their engine pulled could help with this it would be appreciated.

Share this post


Link to post
Share on other sites

Upgrade today to remove Google ads and support TLF.

If you did decide to go the crank pulley route, Lotusbits provided my trigger wheel, sensor, and mount. It's worked fine for the last 7 years.

Share this post


Link to post
Share on other sites

Here's a photo of the ring gear on the flywheel - you should be able to count the teethIMG_20190912_121240.jpg.7c175a1de6a5349aa1134d0b6c22ca64.jpg

The flywheel measures as one foot across (nicely standard😊) and I've also pictured a measurement of the teethspacer.png.

IMG_20190912_121208.jpg.6f4eb9eee82f8438ba1e14d4e23a4749.jpg

Can you drill the sensor hole by the starter?IMG_20190912_121250.jpg.efcae637f6af97b8e0aedb6dc22b62cf.jpg

 

  • Love 1

Share this post


Link to post
Share on other sites

Tony, I'm really trying to avoid that route. Besides hating the look of a pulley mounted trigger wheel my inner Chapman doesn't like the idea of adding parts when there's another option. The ring gear also provides a nice stable signal without the worry of wheel or sensor vibration.  

That being said I might decide the convenience is worth it and follow your lead.

Tom, those pictures are just what I needed. Thanks. It looks like it should work quite well.

  • Like 1

Share this post


Link to post
Share on other sites

Well I might have an issue with this setup. Red line with a 128 tooth wheel puts me just shy of 15kHz for the sensor signal. Right near the sensor operating limit and typically higher than most after market ECUs can deal with.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...