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Topic Durametric vs. BT-1 throttle readings on OBD port |
Not e-gas Trygve (San Francisco, CA) - 7 years ago |
I'm just trying to think it through grant - 7 years ago |
Definitely not airflow Trygve (San Francisco, CA) - 7 years ago |
There's only one sensor Boxsterra - 7 years ago |
The throttle position sensor... Pedro (Odessa, FL) - 7 years ago |
With the ... Pedro (Odessa, FL) - 7 years ago |
I bore TBs ... Pedro (Odessa, FL) - 7 years ago |
Re: I bore TBs ... MarcW - 7 years ago |
Quote
Pedro (Weston, FL)
... and include a new butterfly valve to fill in the new bore.
On cable-operated TBs, I assure you that the butterfly closes all the way.
It has a very powerful spring that keeps it completely closed.
The only air that gets in when the pedal is not depressed is through the idle control valve.
Here is a side-by-side picture of a standard non-egas TB on the left and a bored out non e-gas on the right.
Note how the butterfly perfectly seals the bore on both TBs.
[pedrosgarage.com]
Happy Boxstering,
Pedro
Re: I bore TBs ... Pedro (Odessa, FL) - 7 years ago |
Quote
MarcW
Sorry to nitpit but "perfectly seals"? There has to be some clearance between the butterfly valve and the bore or the valve would/could jam.
The heavy spring keeps the valve closed. But what if the spring breaks? What closes the valve in this case if it is wide open? Besides a heavy spring is not ideal as it increases wear on the butterfly valve shaft and the throttle body bore the shaft resides in. As these wear the butterfly valve then moves from its centered position and contact with the bore is made. An important step in the carb rebuilding process involved replacing the worn butterfly valve throttle shaft and addressing the worn throttle shaft bores in the body of carb.