My Dumb Question [Archive]

LUVNLIFE

01-19-2005, 06:33 PM

Does a #6 take more horsepower to run than a bravo? As in crankshaft hp versus at the prop hp. Just curious. Thanks Cale :idea: ;)

Havasu Hangin'

01-19-2005, 06:49 PM

Yes.

LUVNLIFE

01-20-2005, 08:28 PM

OK,,,Now how much more power does it take :D Or a better way to put it,when is it feasible(?). To put it this way, we can't all just go balls out from the go. Some have to build and improve as they go. So would a #6 rob to much power from say a 525 to make it a feasible route in say a 25-26 footer?

ECeptor

01-21-2005, 07:19 AM

Yes.
Why? Is there some system on a #6 that increases the parasitic losses? More gears, bearings, different oil, different oiling system...???

Havasu Hangin'

01-21-2005, 09:24 AM

Although I have never owned a #6, most guys will probably agree that the Bravo is faster because of:
1. Parasitic loss- 25HP vs 40HP or so on the six.
2. Size- smaller gearcase means less drag on a Sportmaster Bravo to a six (with a similar X dimension).
3. Weight- Sixes weigh more and need a tranny, which would probably affect smaller boats more.
Another reason it's tough to put a six on a 25' cat, is the transom may not be tall enough.
As in almost everything, the #6 durability comes at a tradeoff, that affects some boat more than others.

Boatlesss

01-21-2005, 09:38 AM

The #6 takes over twice the HP of a Bravo b/c it has twice the mass of parts.
There are two vertical shafts, two sets of gears, etc.
The drive has twice the weight of a Bravo which changes the balance of the boat. The engine has to be moved forward by some 16" so the balance of the boat goes from bad to worst.
Then look at the cost.
There are better alternatives.

LUVNLIFE

01-21-2005, 04:32 PM

Thank You guys. Now what are the better and best alternatives? Do you mean the upgrades some of the shops sell? (Teague,Imco and such)

ECeptor

01-21-2005, 08:54 PM

I read an article in Family and Performance Boating magazine about the Konrad 540 outdrive. It was an direct bolt up replacement for the old TRS drives, but was built to handle pretty stout engines. I think it was rated up to 750ft-lb of torque, which is quite a bit.
I don't know if Konrad has any drives that use the Bravo bolt pattern.