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Old 12-30-2008, 06:30 PM   #12 (permalink)
SlowMo
Reformed racecar mechanic
 
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But there must be an optimum length, probably related to engine displacement and desired rpm. This sounds more complex than 'slap a 1/2" spacer in it and go!'... come to think of it, probably related to cam timing too b/c the valve opening and closing would set up the pressure pulses. Kind of like expansion pipes on 2-stroke motorcycles, no? (just on the intake side, and with valves...)

I'm also confused by the claims of lower RPM gains because this article Best Carb Spacer Cheap Horse Power - Popular Hot Rodding Magazine emphasizes the gains in the upper rev range (although there are some mid-range gains too) like Christ states, but I'm not an engine builder and I'm more than a bit rusty at all of this.

This leads me back to the use of a TB spacer as a thermal break rather than as a method of tuning the resonant frequency in the intake tract.

Last edited by SlowMo; 12-30-2008 at 06:32 PM.. Reason: add'l thought
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