Thinking about re powering from a 5.7 to a 8.1L..will my drive blow up?

Nick70

Active Member
Apr 20, 2016
206
New England
Boat Info
2006 Searay 260 DA 496 mag
RAYMARINE stuff.
Engines
496 Magnum
Bravo III
i found a good deal on a used 8.1 HO..I'm ready to pull the trigger.
But talking to a friend with experience, he says the whole thing is asking for trouble. That my Bravo III outdrive, having been worn in by the 5.7L could blow up having a new more powerful engine hooked up to it.
Opinions? Anything else I may not be aware of?
My boat is a 2006 Sundancer 260. I want to keep it, having put a ton of upgrades in electronics etc..plus I really like the boat. I also would love the extra power too. The 496 was offered on the boat from the factory so I thought that was encouraging...I'm assuming it's the same outdrive for either engine, being a Bravo III.
Any opinions welcome, thanks.
 
Total BS from your buddy. Granted the B3 can come in the X or XR drive which is beefier, but your boat isn't that heavy and shouldn't put a huge strain on it. Look at the ratio on what you have, gonna need a prop change.

I'd say go for it
 
Looking at repowering options offered by Merc shows 8.1s with Bravo ones, twos and threes. Pricey, however. Might be cheaper to by one already set up the way you want it.
 
Transom assembly and lower unit are definitely OK......as I said in your other thread, check on the gear ratio - you may need a new upper (or change gears in yours) may also need to re-prop - if you do decide to buy a used motor, get oil samples and a compression test and/or leakdown.......what kind of boat did it come out of? is it closed cooling or open? was it set up for v-drive or outdrive? Are you getting the ecm with it?
 
The BIII will be fine. What gears and props are you running now? You will definitely have to change one or the other.

Expect your fuel economy to be nearly identical and you will run the same speeds about 800-1000 rpm lower. Getting on plane will be way, way easier.
 
If you are going to get new props to change pitch I second getting 4 blade Hill Marine 4x4 propsets. I have them on my bravo III and they are excellent and less expensive thank Mercury props as well. Better low end maneuverability, better hole shot, and lower Planning speeds.
 
My '05 260 has a 8.1 HO with a BIII. I think the 06 model is the same weight and size, but I haven't checked. I've got a 2.2 ratio gear set in the BIII and 26 pitch props. She'll get right up to the 5K red line.

Say bye-bye to any problems getting up on plane. No matter how many people, fuel, water, supplies I put on board, she gets right up. It feels like I am the only one on board every time. Enjoy!
 

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