Performance "Out of the Hole"

[Rusty]

Looking for Assistance:
I have a 1999 32 Luhrs Open, powered by twin Cummins 330 B straight 6 turbo charged disel engines. The maximum rated rpm of the engines is 2800 rpm. The propellers are twin counter rotating 4 blade bronze alloy 21" x 21". I have owned the boat for 4 yearrs.

1) Testing: On 11-01-06 I checked the output of the engines with a tach gun at full throttle. Port engine 2850 rpm, starbord engine 2870 rpm. I did have 7/8 full fuel load and 0 fishing weight aboard. Conclusion engines and propellers performing to specification. Previous year maintenance included exchangers, injectors, pumps, etc. Two years ago, the propellers were checked by a shop and were in good shape.

2) Problem: With full fuel, people, ice, etc., the boat is very difficult to get "out of the hole". I will plow for a long time puffing black smoke. I sometimes have to throttle back quickly and let the rear wave give me a kick and re-throttle.

3) Running: Once some of the weight is burned off in fuel and the boat is lighter, perfromance "out of the hole" improces dramatically. Black smoke is not an issue, as performance is of no significant problem. Depending on the direction of the sea, the "out of the hole" condition is present, but not as bad.

I know someone out there is a prop man or may have had the same problem. I think the answer may be in the propellers; however, I do not know where to begin.

With respect to this issue, I am pleased with all other performance.

Thanks for any direction !!

Rusty

[HisDoghouse]

Rusty,

I hate to ask this question, but what's the condition of the bottom and running gear?

Another thought. My 38 Open comes up much easier if I pre-deploy my tabs before I come up on throttle. You don't mention trim tab use when coming up.

Good luck,

[Reel-Deals-1st]

It looks like your boat was certified with a 21x22 4 blade flats. How do the engines react when getting on plane? Do they turn up, but no go anywhere or do they bog and seem overloaded? Like dogHouse said,the condition of the bottom is also a major factor in this also. -Jeff

[Rusty]

Boat Bottom: Maintained, just had new bottom job two weeks ago.

Trim Tabs: Fully deployed for bow down. This is a must to get up. I am not impressed with the trim tab action; however, they work. Boat likes to run with bow down.

Engine: Boat very sluggish in acceleration out of the hole. Turbo late to kick in at 1800 to 2000 rpm. By my understanding, turbos will not kick in until rpms are developed. Due to weight, rpms are slow in time to develop.

Thanks for comments, but my focus falls back to props. I am worried to modify props to get better hole shot and decrease top end performance in fuel efficiency, etc.

Rusty