Repower Options ?

[Bill Desmarais]

I’m posting this question for a boat owner friend who has a 32 H&H (Osmond Beal down east) lobster boat.

Right now the boat is powered by a 1999 Isuzu 6 cyl. Model A-6BG1T 230 hp rated @ 2500 rpms. The engine is keel cooled with dry stack exhaust. Tranny is a ZF63A 2:1 gear, 1.5” shaft with 24X22 #3 cup prop. Weight is a guess @ 12,000 lbs +-. Owner stated the boat is “heavy” for the sea trial.

I sea trialed the boat this past week and photo tached the engine.

Data:

High speed neutral was 2930
Two WOT runs into a head sea and following sea the engine reached 2435 rpms.
GPS speed was 16.8 knots.

The owner is considering a repower during the upcoming offseason and wants a cruise speed of 17 knots minimum without beating on the engine. The boat is used as a tuna stick boat. 40 mile cruise round trip out to the tuna grounds with all day idling around in gear looking for fish. Figure 200 +- annual usage or more. The owner wants a gear that will drive steering hydraulics.

My experience with the 32 H&H hull is that it’s most comfortable at a 17-19 knot cruise.
The hull is capable of speeds in the low 20s but will begin to “keel walk” at or above 21 knots.

The owner was originally considering a ReCon 6BTA 315 but now is concerned that @ 315 hp that may not be enough “oomph” to get a solid 17-19 knot cruise without beating on the engine.

Your opinions? Thoughts?

Thanks, Bill D

Topic

[Bill Desmarais]

Rob,
I’m confident the repower of this older 32 H&H will be no more than a ReCon engine.

[Rob Schepis]

Not sure how much $$$$ the owner is willing to throw at this but Tony was involved in a new build 32 H&H with a QSB 6.7 recently… might be more than this owner needs..

[Bill Desmarais]

Thanks Tony,

I’ll pass this information along.

Is the 6BTA 370 still the “bang for the buck” if you want some in reserve for “going faster” at times ???

And the 16.8 knots was against the wind into a head sea.

We got the same 16.8 in a following sea.

[Tony Athens]

This is actually quite simple because of the homework you did..

We know now what a “maybe 230 HP” does as to performance — 16.8 Kts GPS speed ..(not always the best unless you did that in multiple directions to make up for current).. But that does not really matter right now ..

Both the 330 or 370 Diamond are easy 12-13 GPH cruisers when set up right used in under 500 hours a year service…..That’s right at 230-260 HP– The weight will not change much so if 17 Kts cruise with a 22+ top end works, then you got it without question–Probably a 1.75 gear using the same prop will do it–Some tweaking can come after seatrial..

If he wants more, then it’s the “Q” engine..

Tony

[Bill Desmarais]

Rob,

He is considering both the 6BTA 5.9s and QSB 5.9s

The new engine will be raw water cooled, 6″ exhaust….typical setup

[Rob Schepis]

Hello Bill,
Engine box or flush deck?
Do you have any pics of the current install?
Is the owner “anti-Q-series” and wishing to stay mechanical?

[Author]

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