the quest, engine advice.

Designs for inboard or outboard power

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china
Posts: 83
Joined: Tue Mar 21, 2006 9:09 am
Location: LONDON.UNITED KINGDOM.

the quest, engine advice.

Post by china »

hello, i am building the quest. a houseboat with the hull of a speedboat.

the question is instead of an outboard i am using two inboards.
if the recomended power of 200 hp outboard is recomended, what is the suitable size engines equivelent inboards i can use?

ie, what size inboard engines are equivilent to 200hp outboard?

any help please.
London. England.
Building to escape the city !

Amm
Posts: 178
Joined: Thu Jun 01, 2006 9:54 am
Location: Utah

Post by Amm »

Maybe the plans say different or give more wiggle room, but the most limiting factor looks like the allowed weight of the engines. http://www.glen-l.com/designs/house/quest.html
Total engine weight not to exceed 600 lbs.

If you need twins, then the only way I can think to do it is with twin small outboards. A single 200hp outboard is around 500 lbs. You could probably get 100hp outboards that weigh around 300 lbs a unit.

For an i/o, the weight of a 4cyl engine with alpha drive is 635 lbs http://www.mercurymarine.com/engines/in ... _specs.php

I am sure there are other ways to do it, but I don't know them.

china
Posts: 83
Joined: Tue Mar 21, 2006 9:09 am
Location: LONDON.UNITED KINGDOM.

Post by china »

thanks am , just what i wanted realy. weights and sizes, hhmmmm, i realy did want twin inboards as i want to use diesel instead of petrol and did'nt want anything hanging off my transom.

plus i wanted twin inboard as i wanted to put on one reverse and use ploughing action to help sidways mooring/berthing.

so i want after reading what you said, i realy want two inboards that are 300 lbs each. but with that weight ratio could i realy reach up to 200hp.

matbe i could reinforce the structure to take more weight and then get two bigger engines.

i hope there is a way.

any other ideas anyone.

cheers.
Last edited by china on Thu Jul 05, 2007 2:17 pm, edited 1 time in total.
London. England.
Building to escape the city !

Amm
Posts: 178
Joined: Thu Jun 01, 2006 9:54 am
Location: Utah

Post by Amm »

http://www.yanmarmarine.com/products/product_jh.php
Diesels are generally a lot heavier. 100 hp engine is 500 lbs. 200 hp engine is 800 lbs.

If you want twin diesels, maybe a larger boat?

china
Posts: 83
Joined: Tue Mar 21, 2006 9:09 am
Location: LONDON.UNITED KINGDOM.

Post by china »

thanks amm. i realy appriciate it.

i might have to write to glen l and see if i can reinforce the boat to take the extra weight of the engines. i dont want to fit it out with beds and all that stuff, but also i would like to put twelve passenger seats too.

it would need a lot of strenghening, i wonder if i can get sombody to upgrade the plans?

cheers for the help amm. i will check that web site out now.
London. England.
Building to escape the city !

china
Posts: 83
Joined: Tue Mar 21, 2006 9:09 am
Location: LONDON.UNITED KINGDOM.

Post by china »

has anyone got any good ideas on how to strenghen the quest speed/houseboat.

i am going to have 200 pounds extra weight over for the engines and i would like to strenghen it so it could take up to 12 passengers.

it wont be kitted out like a houseboat so water and plumbing wont be needed. basicly just twelve couch/bus style seats and the two inboards realy.

i do hope somone can help.

cheers.
London. England.
Building to escape the city !

FDMSIV
Posts: 407
Joined: Tue Jun 06, 2006 12:28 pm
Location: New Orleans

Post by FDMSIV »

The fastest way to strengthen your hull is by increasing the size or number of longitudinal stringers. The height of the stringer is what needs to be increase, the width doesn't play that much into the strength of the member. I am assuming that you are going to have a minimum of 2 large stringers for engine support. If you are using 2x6 stringers, consider using 2x10 or something along those lines

Dale Mattson
Posts: 33
Joined: Sat May 12, 2007 3:13 pm
Location: California

Post by Dale Mattson »

You know what would be really cool?
Use the drive line from a 1995-1998 Sea Doo Speedster.
Twin engine Jet drive!
There was a crashed one on ebay that just sold for $2800. That was the whole boat and trailer. All the steering, electronics, engines, jet drives, fuel tank, everything!
Parts are available, and not SO expensive.

That's my 2 cents worth....

Peace
D
Don't believe the hype.

china
Posts: 83
Joined: Tue Mar 21, 2006 9:09 am
Location: LONDON.UNITED KINGDOM.

Post by china »

wow. thanks alot all. i realy appriciate the help you are giving. it realy is showing me that this boat is possable and fit for perpose.

thanks fdmsiv, thanks dale mattson,thanks amm.

if when i get this boat built and you are ever in london, get in touch and i will show you around london on it.

cheers for the advice for the strengthning adaption process. i have gottten some books on boat strengthning from the library so this might help me understand them.

cheers.
London. England.
Building to escape the city !

china
Posts: 83
Joined: Tue Mar 21, 2006 9:09 am
Location: LONDON.UNITED KINGDOM.

Post by china »

i know we aint suposed to changed designs on the boat as they have not been tested and have not been checked out with a naval arciteque.

do you think the quest house boat could go another four foot longer.?

do you think i could get glen l witt or another arciteque (please excuse the spelling.) to add additional plans so i can make the quest a bit longer?

just wondered if it is possable as it would be great to have additional space, it would be just used for river work.
Last edited by china on Wed Sep 19, 2007 11:56 am, edited 1 time in total.
London. England.
Building to escape the city !

china
Posts: 83
Joined: Tue Mar 21, 2006 9:09 am
Location: LONDON.UNITED KINGDOM.

Post by china »

scrap that. i am keeping it the same length now and will be having twin outboards now.

thanks for the advice.

any more would be welcome. :) cheers.
London. England.
Building to escape the city !

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