mesin buat kapal kayu panjang 14m lebar 1,8m

[therockmelon]

salam,

saya sedang membuat kapal kayu panjang 12m lebar 1,8m yang rencananya akan dipasangi inboard dongfeng 30pk dan juga outboard yamaha 40hp.

1. pertanyaan saya apakah bisa balance jika saya pasangkan komposisi tersebut?
2. kira kira larinya bisa berapa knot?

alasan saya memasang cuma 1 outboard karena gak kuat bayar bensinnya tiap kali ngetrip. hehehe

mohon petunjuk para boat experts in this forum.
looking forward for your advices and suggenstions.

thanks

christian

[Sportfisherman]

Bentuk kapal untuk outboard beda dgn bentuk kapal untuk inboard , kalau melihat ukuran kapal sih dapat dipastikan mesin tempel yang hanya 40 hp tentunya tidak efficient untuk mendorong kapal sebesar itu dan cenderung boros penggunaan BBM nya krn " over loaded " .

Khusus untuk kapal sekitar 12 m , hull speed nya 8 knots . Diatas kecepatan ini diperlukan tenaga yang jauh lebih besar untuk mendorong kapal tersebut diatas hull speed tersebut , check this : Hull Speed (http://www.sailingusa.info/cal__hull_speed.htm)

Penggunaan mesin inboard lebih komplex permasalahan nya , bukan dgn DongFeng 30 HP terus bisa menjelaskan kecepatan kapal , harus di tinjau ukuran propeller nya juga tetapi umumnya , mesin diesel yang balance dgn body kapal akan bisa lebih irit jauh daripada mesin tempel pada hull speed tersebut dan umumnya umur mesin pun lebih awet .

Buat apa menggunakan 2 mesin yang berbeda sifat nya , mesin tempel umumnya lebih efficient pada RPM tinggi sedangkan mesin diesel lebih efficient pada RPM rendah , sangat bertentangan keduanya dan hasilnya pun kemungkinan besar tidak effective untuk mendapat penambahan kecepatan yang berarti .

Jon .

[therockmelon]

thanks for your opinion mr.john, i didnt know that all those aspects need to be counted properly. I am really 'blind' about boating,hehe. thanks again for your opinion, i really appreciate it.

christian

[therockmelon]

Mr. john

what do you reckon should i use as the main engine/s for my boat?
a PS120 mitsubishi or a pair of yamaha outboards?
how much power the boat needs for the outboards?

thank you

christian

[Sportfisherman]

Mr. john

what do you reckon should i use as the main engine/s for my boat?
a PS120 mitsubishi or a pair of yamaha outboards?
how much power the boat needs for the outboards?

thank you

christian

Hi Christian ,

Without knowing how your boat is built , I can not say much but these are the facts ;
Inboard diesel has the economic and long service life aspects while outboard will give you a better speed but poorer fuel economy . If the boat is going to be used continuously , I think it's wise to consider diesel but if the boat is used occasionally , perhaps outboard engines are a wiser choise .

The enemy of speed is nothing truer than weight of the boat + equipments + load , one must carefully calculate the weight of the boat and then ask the engine supplier to calculate the size of the propeller(s) , knowing how they operate in the remote areas of Indonesia , the only option is to get 40 hp outboard motor and if one needs more power , double the number of engines but this add weight and not necessarily translate into double the power , an 80 HP single engined boat will run circle the same hull with 2 x 40 HP engines .

When one is trying to use truck engine as power train for a boat , one must not be mislead by the horsepower rating of the road vehicle and that of the properly marinised engine . It's better to take the rating of a heavy equipment such as tracktor when comparing the HP of the marinised engine . A 120 hp road vehicle rating may only be at the most 80 hp in marine rating , one needs to change the flywheel n buy a reversing reduction gearbox to as well as do the marinisation , if money is no object better buy a proper light marine engine such as Cummins , Yammar , etc. .

Jon .

[monyet]

Once I have a wooden boat with 14m length and 2.4m wide, a Mitsubishi 100ps land engine gave me satifying result for years of good relliable service. The top speed might around 9.5 knot, but the engine seems working hard. Ideal trolling speed is around 5 knot, and ideal cruising speed is around 7-8 knot. At crusing speed the engine will revving happily.
I forgot the propeller size and gearbox ratio.
So, I think a 100ps or 120ps land diesel engine is a reasonable choice.

Kalow marine engine mah gak kuku..... mahal dan sparepartnya syuysah nyari...

[Rudy 007]

Sorry oot nih cuma penasaran aja.
Di mana bedanya mesin diesel truk yg standard dan yg sdh di marinize (bener ga tuh tulisnya)? Apa sekedar di buat anti karat atau bgmn?

[B4H4R1]

Maaf, sekedar saran.

Pilihan utk anda
1. mesin 1 silinder 30 HP + marine gearbox
Mesin : merk Jiang Dong
Tipe : JD 300
Merk Gearbox : Advanced
Tipe 16 A, ratio 3 : 1

2. Mesin Mitsubishi + marine gear box
PS 100
Gearbox : Advanced, 16A ratio 3 : 1

3. Mesin Mitsubishi + marine gear box
PS 120
Gearbox : Advanced
Tipe : 40 A, hidrolis, ratio 3 : 1


Saya lbh condong no 1 atau 3. Mengingat sparepart lbh mudah dari importirnya. Terutama utk gearbox nya. Setelah itu baru anda beli propellernya (ukuran di sesuaikan dgn mesin).

Atau anda dapat survey ke kapal2 nelayan dgn pedoman mesinnya.

Semoga ini dpt membantu anda. Trimmmm :-D:-D:-D

Thanks

[therockmelon]

@ Mr. Jon
thanks for sharing your expertise to me, that really open my mind about boating. I go fishing every saturday(almost every weekend) because my house is only 100 metres from the sea, it is a blessing for me. I will keep your suggestions in my mind as i will use it someday with my next boat project :) hopefully. I have bought a 30hp dongfeng engine and a 40hp yamaha outboard, I should've asked you before I bought all those things,what a shame.

@ Mr. Ferry
thank you for your sharing, 120PS is really a good choice, i'll consider about it for my next project.

@ Mr. Andreas
terima kasih buat saran nya, untuk sementara saya akan menggunakan dulu mesin mesin yg telah saya beli karena sudah terlanjur :(

thanks for all of you that shared very important and useful information for me. Eventhough i feel a bit regret for not asking before taking action I am glad to know you all. thank you and God bless you all.


best regards
Christian

[Jabricks]

Sorry oot nih cuma penasaran aja.
Di mana bedanya mesin diesel truk yg standard dan yg sdh di marinize (bener ga tuh tulisnya)? Apa sekedar di buat anti karat atau bgmn?

beda desainnya bro, marine diesel di desain punya torsi tinggi di putaran rendah. jadi perbandingan volume silinder x langkah beda sama masin darat. itu yang bikin marine engine lebih bertenaga dan lebih irit.

lalu mesin marine radiatornya pake air laut untuk pendinginannya.

[Rudy 007]

Lho bore dan stroke nya jg beda? Soalnya pernah bc iklan bbrp kali. Misal di jual kapal ukuran sekian dgn mesin colt diesel 120 ps marinized already, nah yg ini yg gw ga paham.
Mungkin yg ini beda di radiatornya itu kali yah.

[Jabricks]

betul bro, radiatornya udah disulap supaya bisa pake air laut, tapi bukan air laut mengalir diantara lubang2 blok mesin lho, airlautnya ngedinginin kapiler radiator aja...
sama gearboxnya juga lain, ga ada persneling 1,2,3,4 hahaha...