Thread:

LS1 + Bravo - Couple/Flywheel help?

So...I'm thinking about putting an LS1 engine with a Bravo XR outdrive in my next boat. I'm having a hard time finding a suitable flywheel and coupler. That's probably because I know very little about outdrives in general. Currently I have a PTO for the LS1 for my jet; but I know that's not how an outdrive works.

I need a flywheel and coupler, correct? That's how an outdrive connects to an engine, right?

The bolt pattern on the crank flange bolt pattern is 6x3.11", std Chevy diameter, 168 tooth. Anyone know if I can use the 496/8.2L Mercruiser stuff? If not...what else is out there?


Thanks!

...guess I just hadn't called enough people. Bob @ Teague had the answers (and the flywheel and coupler) to fit a GM LS series engine.

Originally Posted by tmoore

I used a regular ls flywheel and standard Bravo coupler... I got the flywheels from Jegs for $99 each.
I put a couple ls's in my 24 Skater.

You just jigged it up and drilled the flywheel to match the coupler?

Do you/must you use a bellhousing? I ask because right now I have a top mount starter, and I'm fairly certain I wouldn't be able to use that with an outdrive?

Originally Posted by tmoore

The bravo coupler attaches using the bolt holes where the pressure plate goes. It just bolted right up, no drilling or anything.
You will need to run the bravo bell housing because that's where the rear motor mounts are.
I'm running an IMCO 12" longer input shaft and moved my engines 12" forward and use different mounts.
I think I've heard of Bravo bell housings with top mount starters but I've never seen one.

Ok thanks, I didn't know if I could use a rear motor plate instead of a bellhousing.


What mount are you using?

Originally Posted by tmoore

I'm using aluminum rails with a mid-plate sandwiched with a bravo bell housing, but I'm not using the bravo mounts on the bell housing.
I made front mounts to go from the rails to the motor mount pads.

Ok thanks. I have a Lightning motor plate right now. Sounds like I could re-use that?

Originally Posted by tmoore

If I were you I would use the bravo bell housing for the factory rear mount. Bravo drives are real finicky about the alignment and the factory bell housing sure makes it easier.
The only reason I'm using the mid plate is I'm using the 12" extended input shafts and the factory mounts wont work.
You can find bell housings used on OSO for less that $100 all the time.

Thanks for the help. What did you do for a sea water pump? More specifically...the bracket - and the serpentine pulley?

Originally Posted by tmoore

I'm using a Crusader pump and pulley for a 6.0l. The bracket is made into the pump and bolts to the block where the power steering pump usually goes.
I cut the bottom half of the truck alternator/power steering bracket off and used the top for the alternator the sea water pump bolts on right below it
and uses the factory truck belt. Some day I want to do closed cooling, but for now I run the water out of the pump through the exhaust manifolds in series, then into the engine.
I made a plate to replace the water neck on the inlet side of the factory water pump and plumbed in a -12 line, I blocked off the opening between the front and back part of the water pump in the thermostat area and blocked off the heater hose connections. My water temp runs about 150-155 crusing and goes up to about 170 WOT with 13-15 lbs of pressure. Here is a link to the pump... Crusader Illustrated Parts Books I also used their exhaust manifolds, but I built my own risers.

Thanks. I found the price there too. Off the top of your head, do you remember the inlet/outlet size of the raw water pump?