Bertram31.com General Bulletin Board

Re: Priceless or pricey!

Posted By: garyS - NJ
Date: Tuesday, 6 June 2006, at 12:51 p.m.

In Response To: Re: Priceless or pricey! (JK)

I'm not a boat builder/owner but backpressure effect is the same for all engines. I learned from experience running harleys and cars. generally a drop in backpressure will drop torque unless you increase the intake flow. drop the backpressure, increase the intake CFM and you're moving better. with cars, a low restriction exhaust goes with bigger carb & often different cam (cams are designed for different RPM ranges, high RPM with high volume (cam duration), means steep lobes). with harleys, chopping the pipes short generally drops the backpressure and goes with a bigger carb and or at least jetting the carb to keep the mixture rich enough (did I mention mixture?). longstory short on a boat with modified exhaust, you might want to optimize your intake or perhaps change props (props a story in itself). but then again, fuel (I think doug mentioned) is so important/basic. On friend's boat, I've seen max RPM go up with new clean filter seperator. I recently read same.

Messages In This Thread

Priceless or pricey!
JimmyG -- Monday, 5 June 2006, at 12:46 p.m.

Re: Priceless or pricey!
Doug Crowther -- Monday, 5 June 2006, at 2:48 p.m.

Re: Priceless or pricey!
JimmyG -- Monday, 5 June 2006, at 3:56 p.m.

Re: Priceless or pricey!
Walter Kaprielian -- Monday, 5 June 2006, at 4:16 p.m.

Re: Priceless or pricey!
JK -- Monday, 5 June 2006, at 5:53 p.m.

Re: Priceless or pricey!
garyS - NJ -- Tuesday, 6 June 2006, at 12:51 p.m.

Re: Priceless or pricey!
Capt. Dave Kosh -- Tuesday, 6 June 2006, at 12:57 p.m.

Re: Priceless or pricey!
JimmyG -- Tuesday, 6 June 2006, at 4:34 p.m.

Re: Priceless or pricey!
Doug Crowther -- Tuesday, 6 June 2006, at 8:14 p.m.

Re: Priceless or pricey!
JimmyG -- Wednesday, 7 June 2006, at 12:34 a.m.