×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

4-stroke eng. exhaust pipe chamber (?)

4-stroke eng. exhaust pipe chamber (?)

4-stroke eng. exhaust pipe chamber (?)

(OP)
I spotted an additional exhaust runner resonance chamber on BMW 450cc motocross bike engine, see provided link.

I have tried to wrap my head around the design function of said chamber with no results. This does not seem to be an anti-reversion chamber.

I have however seen similar chambers on 4-cylinder naturally aspirated rally car engines. Chambers are there to even out torque curve. They're connecting cylinders 1-2 together, and 3-4 together (if my memory serves me right).

Would this BMW factory racing exhaust chamber serve same function?


http://juhasalminen.pictures.fi/kuvat/Motorcycle%20Exhibition%2C%20Finland%2C%20Feb%20%28MP%202009%29/7H1B2179.jpg/full


http://juhasalminen.pictures.fi/kuvat/Motorcycle%20Exhibition%2C%20Finland%2C%20Feb%20%28MP%202009%29/7H1B1989.jpg/full

 

RE: 4-stroke eng. exhaust pipe chamber (?)

I have absolutely no idea what we are supposed to be looking at! Can you explain more and put some arrows on the pics?

RE: 4-stroke eng. exhaust pipe chamber (?)

My understanding from having run some simulations on those MX motors is that it's just there to smoothen the resonance action across the RPM band. Smoothen out the power delivery.

RE: 4-stroke eng. exhaust pipe chamber (?)

This is a derivative of the FMF PowerBomb style chamber.  Typically FMF is claiming a smoother/stronger boost in the low rpm powerband.  They also say that there is a 1-2 dB reduction in the exhaust level.

Swiss

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources