Bertram31.com General Bulletin Board

Re: Diesel vs. Gas HP

Posted By: Capt Patrick McCrary
Date: Thursday, 22 September 2005, at 7:44 a.m.

In Response To: Re: Diesel vs. Gas HP (Paul Haggett)

Paul,

I can't remember which diesel engines you're installing, but unless they're over 350HP & combined with Cabrera's prop pockets to reduce the shaft angle to 10°, don't hold too tightly to a 40 kt flat out expectation...

Standard 15° shaft angle, 3 blade Nibril wheels, 1.5:1 gears, 300HP - 320HP, fully loaded with gear, personnel, & fluids will top you out around 34 - 35 kts. Substituting 2:1 gears & 4 blade Nibril wheels will bring your top end down to 31 - 32 kts, but give you better mid range cruise characteristics.

Over 350HP with the Standard 15° shaft angle & you'll nose dive at 29 kts & probably wouldn't see over 30 kts.

If you do manage to attain speeds over 32 kts, know that the B31 is going to go from very tender handling at around 33 kts to right down squirrelly above 35 kts. I'd consider 40 kts getting well into the danger zone...

If you're using Danny's, (HighTide Marine), monster struts, you need to taper both exterior ends of the shaft tube to better match you cutlass bearing & to reduce drag and cavitation...

Br,

Patrick

Messages In This Thread

Diesel vs. Gas HP
STeveZ -- Wednesday, 21 September 2005, at 9:34 a.m.

Re: Diesel vs. Gas HP
Capt. Dave Kosh -- Wednesday, 21 September 2005, at 10:07 a.m.

Re: Diesel vs. Gas HP
Walter Kaprielian -- Wednesday, 21 September 2005, at 10:18 a.m.

Re: Diesel vs. Gas HP
Capt. Dave Kosh -- Wednesday, 21 September 2005, at 10:26 a.m.

Re: Diesel vs. Gas HP
Carl -- Wednesday, 21 September 2005, at 12:36 p.m.

Re: Diesel vs. Gas HP
Paul Haggett -- Wednesday, 21 September 2005, at 4:29 p.m.

Re: Diesel vs. Gas HP
Capt. Dick Dean -- Wednesday, 21 September 2005, at 4:55 p.m.

Re: Diesel vs. Gas HP
Dug -- Wednesday, 21 September 2005, at 5:54 p.m.

Re: Diesel vs. Gas HP
Paul Haggett -- Thursday, 22 September 2005, at 6:31 a.m.

Re: Diesel vs. Gas HP
Capt Patrick McCrary -- Thursday, 22 September 2005, at 7:44 a.m.

Re: Diesel vs. Gas HP
Paul Haggett -- Friday, 23 September 2005, at 6:47 a.m.

Re: Diesel vs. Gas HP
John F. -- Friday, 23 September 2005, at 7:07 a.m.

Re: Diesel vs. Gas HP
Ed C. -- Thursday, 22 September 2005, at 6:51 a.m.

Re: Diesel vs. Gas HP
Doug LeBlanc -- Thursday, 22 September 2005, at 1:00 p.m.

Re: Diesel vs. Gas HP
Doug LeBlanc -- Thursday, 22 September 2005, at 1:04 p.m.

Re: Diesel vs. Gas HP
Paul Haggett -- Friday, 23 September 2005, at 6:50 a.m.

Re: Diesel vs. Gas HP
Doug LeBlanc -- Friday, 23 September 2005, at 9:54 a.m.

Re: Diesel vs. Gas HP
Scott -- Thursday, 22 September 2005, at 8:35 a.m.

Re: Diesel vs. Gas HP
Capt Patrick McCrary -- Thursday, 22 September 2005, at 10:07 a.m.

Re: Diesel vs. Gas HP
Dave Diamond -- Thursday, 22 September 2005, at 12:01 p.m.

Someone told me, you can buy a lot of gas for $20K
STeveZ -- Thursday, 22 September 2005, at 8:26 p.m.

Re: Someone told me, you can buy a lot of gas for
Dug -- Friday, 23 September 2005, at 9:05 a.m.

I was looking at the upgrade on a used B28
STeveZ -- Friday, 23 September 2005, at 9:23 a.m.

Re: Someone told me, you can buy a lot of gas for
Doug LeBlanc -- Friday, 23 September 2005, at 10:01 a.m.

Re: Diesel vs. Gas HP
randall -- Thursday, 22 September 2005, at 1:23 p.m.

Re: Diesel vs. Gas HP
JP -- Thursday, 22 September 2005, at 2:13 p.m.

Re: Diesel vs. Gas HP
randall -- Thursday, 22 September 2005, at 3:17 p.m.

Re: Diesel vs. Gas HP
JP -- Thursday, 22 September 2005, at 4:03 p.m.

Re: Diesel vs. Gas HP
randall -- Friday, 23 September 2005, at 9:35 a.m.

Re: Diesel vs. Gas HP
CArl -- Saturday, 24 September 2005, at 5:20 p.m.

Re: Diesel vs. Gas HP
andre fourrier-Louisiana -- Saturday, 24 September 2005, at 6:53 p.m.

Re: Diesel vs. Gas HP
Carl -- Saturday, 24 September 2005, at 9:24 p.m.