230lx434

SB those numbers were 1.5 measurements. .547In/.563Ex @ 1.6 curently

corey331

I'm really interested to see what kind of power you make with this and where the torque comes in at. I have built a 408ci LS2 that I am putting in my boat, and I also called Bob Madera for my cam. We ended up using one that is 242/250 .621/.613 112*ls. I ended up having lightning build me a set of headers and when he built them he extended the collector out past the back of the header to help fight reversion. I can actually extend it even more if I want, but I think it'll be ok where its at. As of now, the water won't mix into the exhaust till its almost at the transom.

Trash

If it were me the 230/236 would/should work on that size motor but I would prefer a 114LSA. As SB noted you can afford more lift. For reference I'm at 221/230 on a 114LSA with .525/.545" on a 1.5 rocker in a 377 cid motor. No reversion noted to date.

230lx434

I am actually waiting on a call back from Bob so i can give him exact numbers on my heads/flows/ect.. We will see what his suggestion is but from what brief conversation we had when he started my build sheet he says definitely 230s and running the riser extension the way i am going to will be perfect to fight against reversion. Will report back once i know more. Not sure if it'd be out of courteous or not to give all the specs he suggest but if he doesn't care ill let them fly. Corey, i may not know SBC marine engines very well but i do know my way around a LSX motor very well. With you running a 4"+ bore whether you are running cathedral port or rectangular port those heads react a little different to cam specs than SBCs.

230lx434

trash what kind of power are you making?

Trash

Never dyno'd it but netted between 10-12 mph increase over stock 350 Mag in a beamy slow hull. I've also left power on the table with smaller runner size. I would estimate between 370-412 hp. I know that's a big bracket but that's my guess. I've been trying to prop shaft dyno it but getting the time to do it is difficult.

airjunky

20 less cubes one less foot and about 800lbs less hull with a vp dp very similar sbc stroker build gets real close to 80 without going too far past 6k rpm. May have a little wiggle room for fancy exhaust water dump options with that particular exhaust set up.
A hot 434" smallblock bravo combo can dump some serious water in the exhaust

Ryan00TJ

Good call working with Bob. He spec'd my last 383 cam. 234/240 .580" /.568" 112+4. Idled very nice with excellent docking manners. I ran GLM alum manifolds and Imco risers with 20" extensions mixing the water in at the tips. No reversion. Never dyno tested but 475hp was estimated. Ran very well for 475hp. I just don't see those small cams you have mentioned pulling the rpms your wanting. The above cam pulled very hard 5900-6200 rpms.

<iframe width="420" height="315" src="https://www.youtube.com/embed/rxT0vfMSJDM" frameborder="0" allowfullscreen></iframe>

SB

OSO does embedded vid's different. Here's ryans vid

https://www.youtube.com/watch?v=rxT0vfMSJDM

230lx434

Talked with him today to give him final head porting specs/valve sizes and flow numbers i had availible. Says more than likely 230s intake 240s exhaust. Im goimg to have it idle around 800-850 and he seems to think with the way i will extend the risers reversion shouldnt be an issue. So i guess we will see. Guess too many people haven't put a good bit more power in these boats? He thinks 575ish should be achievable with a stout leg in it but told him how we cruise im looking for 75-80% out of 100 on cam size vs power scale.