Finally floating again

[Reelcrazy]

So my 31 Bahia Mar is finally re-powered. she splashed today. Running Cummins 6 BTAs 270 hp. 25. 5 knots at 2350 rpms, So happy to have the old girl floating again.

[Carl]

Good for you!

Now get out and enjoy her!

...and remember pictures or it didn't happen.

[PeterPalmieri]

nice!

[Tony Meola]

Ray

Good to hear. I wanted to stop by on Saturday to see if you were in but did not have a chance. Maybe I will catch you running across the bay. Nice at 25.5 knots. Makes her a different boat.

[Reelcrazy]

she does run like a different boat. i think the extra weight of the cummins make a big difference. ran up the bay at 26knts in the chop yesterday she didn't pound like she did before

[Carl]

Pound?? I have to say my boat has never pounded...and I have been in some nasty snot with it, launched it off a couple big waves, I've come down hard, got jarred and slapped around.

Now my dads Hatteras or the Cruisers modified tri hull he had before that...Now Those pound.

Anyway, glad to hear the ride has improved.

[Charlie J]

she does run like a different boat. i think the extra weight of the cummins make a big difference. ran up the bay at 26knts in the chop yesterday she didn't pound like she did before

extra weight helps alot

[Carl]

extra weight helps alot

That's what I keep saying, but my wife still says I should lose a few pounds....

[bob lico]

provided the weight is aft of the main bulkhead or in a Bahia Mar 6" forward of engine box engine and gears ready to run Must weight at least 1100 pound each to bury the reverse chine ,not a opinion this is fact as tested on travel-lift numerous times .Anyways good luck and have a great summer.Raymond Hunt original 1961 designed/built with big block 413 cubic inch dodge with cast iron exhaust and cast iron gears,steel generator,starter motor.later moved up to 440" dodge and finally 454" chevy which shed some weight but all close to that number(1100) as today`s volvo,cummins and a little heavier 3126 catapiller. 3208 cat,504 cummins were beast i had 504 cummins in my boat at 1900 lbs each. way to heavy for speeds at wot. in excess of 22 knots.

[Tony Meola]

she does run like a different boat. i think the extra weight of the cummins make a big difference. ran up the bay at 26knts in the chop yesterday she didn't pound like she did before

Ray


26 knots is moving. What were the RPM's? On the Fly Bridge you would be pushing her too hard for continous use, but you have less wind resistance and are probably a tad lighter.

[bob lico]

tony 26 knots is the "golden " speed fora 31 Bertram she starts to ride on her strake and the area between strakes gets air and the boat becomes more efficient at 30 knots you feel like your on railroad tracks (provided the chines are in water) and the boat steers differantly. we get her on top and stay there at 28-30 knots for maxinumin efficiency,motors are rated at 2800 rpm and recommended rpm is 5% off the pin. ours run to 3000 rpm and i run her at 2300 very conservative at 29 knots.the boat drags under 22knots you could feel it at the low end of torque curve and your not saving your engines if they drag like he said "there singing" indeed they are!!!!

[pschauss]

Bob,

How does that apply to 454s? I get about 23 knots at 3000 rpm and about 18 knots at 2500. The ride is comfortable throughout that speed range but this is the first power boat that I have owned (second season) so I don't have anything to compare it to.

Am I putting more stress on the engines at the lower speed? I have heard opinions on both sides here.

[Reelcrazy]

tony brought her home alone the other day. ran up the bay @ 25.5-26 knot @ 2250 rpms full fuel just me aboard.

[bob lico]

your ok at 2500 rpm but that is the bottom of the 454 torque range,with engine box cover off and you slowly apply throttle at what RPM does the secondary of the four barrel carb. open? you can both hear it and feel it.keep the boat just under secondary opening if you want to increase cruise at the cost of a little WOT. speed you would add a little cup to the props .maximum fuel economy should also include the fact your not go going to the fishing grounds at 15 knots. the boat must get up on her strakes as designed or no effort at incresed cruise will make a differants.

[Tony Meola]

Ray

Those were great numbers.

Peter

When we ha d the 454's 3000 rpm got us up to 19 knots. Depending wha t we w are d going we usually rasn them between 2800 and 3000 rpm.

Try cranking them up to 3600, you will feel the boa t hit the sweet spot and she will ride much better. Unfortunately you can't run them like that for long.

She used to get a little squirrelly wide open. Would tend to China walk. That does not seem to happen with the diesels. I think it is the extra weight since the back end sits lower in the water.

[bob lico]

it will not chine walk with cummins diesels because the chines are under water doing what they are designed for.