Repower

[kmclarke]

Hello All.
The boat I am considering (KP44) may need a rebuild or repower. She
currently has a 4-154. If a total rebuild is required I will probably
repower instead. Yanmar is out because of the turbo. I am leaning
toward the Beta marine 3300 75 HP. Has anyone had any experience with converting
these two engines? How much work needed to be done to the eng room to make it
work? what was the cost of that work?
Thanks for the help.
Kevin C

[Valiente]

Originally Posted by kmclarke

Hello All.
The boat I am considering (KP44) may need a rebuild or repower. She
currently has a 4-154. If a total rebuild is required I will probably
repower instead. Yanmar is out because of the turbo. I am leaning
toward the Beta marine 3300 75 HP. Has anyone had any experience with converting
these two engines? How much work needed to be done to the eng room to make it
work? what was the cost of that work?
Thanks for the help.
Kevin C

There are too many variable to give more than a general answer, but some things to consider are the relatively cheap and easy fixes (exhaust change-out and reposition, good time to replace the water lift, haul and inspect the shaft and coupling, and so on). The more problematic stuff involves inspecting the motor mounts: Are they in need of alteration and/or drill and fill (wood cored ones can and do rot).

Another consideration is the location on those mounts of the transmission side of the coupler...is it in line and will the engine have the same angle? If not, you'll have to cut out the shaft log and possibly the cutlass bearing...nasty and expensive.

The Beta is known for replicating the dimensional aspects of competitors' engines, however: their Atomic 4 is truly a "drop in", and they seem to present diagrams that will allow you to determine this fairly crucial aspect of repowering.

[georgellop]

kmclarke,... if I may suggest, you should re power the KP44 with the BV2203 if you choose to install a BETA MARINE engine/trani package.

The BV3300 is to large an engine weighting to much (due in part to the hyd. trani) to be installed on your boat.

Consider some of the specs bellow:

YANMAR/BETAMARINE BV2203

Displ. 122 cuin/134 cuin

Torque 130 ftlbs@2800 RPM/110 ftlbs@1400 RPM

Weight 545 lbs/534 lbs

HP 75 HP@3800/50 HP@2800

The Yanmar is a 50 HP engine, turbo charged to obtain 75 HP @ 3800 rpm! While the BETA MARINE BV 2203 is a naturally aspirated 50 HP rated package.

The BETA MARINE BV 2203 is the recommended engine/trani package for the KP44.

Regards,...George.

[kmclarke]

Hi George.
Thanks for the reply. I am a bit surprised that you reccomend the smaller engine. The 154 is a 62 hp engine . I was going by the standard 2 hp per 1000 lbs. the kp 44 weighs 30,000 lbs without provisions and crew, so the bv 3300 at 75 hp seemed more suitable.

[georgellop]

kmclarke,

...some more #'s for your research:

BV2203, 2:1, 3 BLADE, 19X12, 50 HP, 7.7 KNTS
BV2203, 2.5:1, 3 BLADE, 22X14, 50 HP, 7.8 KNTS

BF2803, 1.88:1, 3 BLADE, 20X11, 62 HP, 8.1 KNTS

BV3300, 2:1, 3 BLADE, 21X14, 75 HP, 8.5 KNTS

I will pm the curves of the 4-154 and the 2203. You will see that the lbs ft max torque are 113 @ 2,000 rpm vs 110 @ 1400 rpm, respectively. You will also see that the the HP is 53.5 HP at 2500 rpm vs 50 @ 2800 RPM also respectively.

Please note that you must use a 3 blade propeller. A two blade propeller is useless. It is very inefficient :. the perceived need for more HP.

Regards,...