2 bolt main vs 4 bolt main

[FreeBeeTony]

Re: 2 bolt main vs 4 bolt main

How much does the boat weigh, what size prop are you turning and what is your speed at 3200RPM's? Are you estimating the HP?

I would like to compare your set-up with mine.

I have a 350 Magnum with 64cc Vortec heads stock valves, roller cam, aluminum highrise intake with Edelbrock 1409 (600cfm) carb.

My boat weighs ~ 4000# and turn a 17" prop. I go 30MPH at 3200RPM.

Just looking for a comparison.

 

[Flukinicehole]

Re: 2 bolt main vs 4 bolt main

I dont know the MPH as the speedo is not working.I`m going to take it out with a radar gun (marine mechanic has one) to get the actual mph.The boat weights 4700 lbs . I`m going t try a few props he has in his shop when this weather breaks to really get it dialed in. I will keep you posted on the progress.Also yes this is an estimate on H.P. as it was not put on the dyno. According to other builds that have run on the dyno this should be right at the 400 mark. It might be 380 or 410 but this is just an estimate.

 

[FreeBeeTony]

Re: 2 bolt main vs 4 bolt main

According to "advertised" builds comparible to mine.....I'm at 300+.........our builds don't seem to be too far off...............that's why I am curious to your performance as compared to mine.

What is the boat manufacturer?

Also.........looks like we stole this guy's thread.........oopps!

 

[Flukinicehole]

Re: 2 bolt main vs 4 bolt main

All your power will come from the cylinder heads and cam selection. In the marine environment you are restricted with the cam but can still easily get 400 hp. A 400hp SBC is very easy to attain with todays technology . My boat is a Mark Twain walkaround weighing 4700 lbs. Vortec heads are good heads and you can get 400 hp out of them but they need to be worked on. Port ,blend bowls etc.etc. and you would have to cut the spring seats for stronger valve springs.

 

[FreeBeeTony]

Re: 2 bolt main vs 4 bolt main

I'm really interested in the numbers you come back with regarding speed at 3200, prop pitch and WOT............

Let me know when you get it "dialed in"..........

Send me a PM if you want..........

What part of LI are you from?

 

[John_S]

Re: 2 bolt main vs 4 bolt main

Tony, I've seen posts over at OffshoreOnly with people running strokers and alpha drives. Some good, some bad. Allot seems to be how hard you hammer the throttle. The boats on that forum also are probably lighter and don't plow the water as much as the type you have. To me, the stroker has too much torque to reliably run with an Alpha. Merc tried an alpha for a short time, with a BB. I believe the HP was only around 320. It is my understanding that not too many of them survived.

For the performance engine you are considering, I thinkl you need a project go fast boat. d Either that, or find another hobby for next couple of cold months!

JohnS

 

[Flukinicehole]

Re: 2 bolt main vs 4 bolt main

I live on the Patchogue river. I will keep you posted on my progress if this cold ever lets up WOW. Were paying for the nice start to the winter.

 

[Reinellchris]

Re: 2 bolt main vs 4 bolt main

4 bolt mains are stronger.my 22' had a gm crate 350
and acheived 45 mph on gps.before the boats was abandoned in the field and the engine filled with water
only had 2 seasons on it

 

[FreeBeeTony]

Re: 2 bolt main vs 4 bolt main

Hi John..........guess part of my problem is cabin fever....I'm really not considering building a stroker at the moment...........just really making conversation and getting info just in case........ I'm actually quite satisfied with my current set-up............but you know we are always looking to go faster!

Yes Flukin........we are definitely paying for the nice weather in the beginning of the season! Will be looking forward to your updates