Crestliner 17' O/B to I/O... Say Whaaaa?

[Ataraxia]

Hey all, this is my first post. So I thought I'd tell you about my project. BTW, I'm loving everyones boat restorations, they are all great. some of you have some big courage with the huge projects. iboats forum is so great, eh? I just wish I found this site 6 years ago when i redid my floor and stringers in my 14' Stinger...

Yup, Outboard to Inboard. It's been on the drawing board for about a year now.

It's a early 80's 17' Crestliner Crusader (AMF), closed bow. I know there already are inboard version of this boat kicking around, but that's not what i want. This boat is being totally redesigned on the inside. There will be more room on board with this inboard setup, than there was with the original outboard. The bow is staying closed as this v hull is designed to take on tuff chop. This boat will see rough water at times, so strength should exceed original standards... early 80's, shouldn't be to hard to exceed

I think unique part of the project is, a massive diet to the structure and the (very light) 200hp engine + Alpha1. Power to weight ratio should be pretty sweet, but she's also deep! I think originally it was a big ol 140hp hanging off the back. I just love her sleek lines


I'm sure I will have a whole bunch of questions along the way.

(hope the pics work?!)

 

[Chris1956]

Re: Crestliner 17' O/B to I/O... Say Whaaaa?

You do realize that a 200 HP ALpha (4.3LX V6 motor) weighs 1100# versus the 400# or less of your V4? For 40# more you could get a 200HP outboard, and really improve performance. I also wonder how you will have more room in that boat with the I/O, since you will need a full motor cover. On a larger boat you can put the i/O under the deck.

 

[oops!]

Re: Crestliner 17' O/B to I/O... Say Whaaaa?

hey ataraxia

WELCOME TO IBOATS

this place is great......and ...like you i wish id found it years ago....then i wouldnt have botched simple jobs.....

uh....im not trying to dissuade you with negitives....but chris is right....

the ob will be faster and take up less room, and weigh far less.

its a great proj.....but you might find when its done....it didnt give you what you wanted to acheive......

ive got a 19 footer that is way too small for my interior plan. before my proj started....i was told to go twin 200 ob's on it.....that would have saved a lot of work.......
but i wanted to do somthing origonal......
you might want to find an inboard with the configuration you want....and get out the measuring tape...between the motor and the transom is the bellhousing....transom plate, and a dozen other things to take up the space you really want......

having said all that.....THIS IS YOUR BOAT.......and you can do what ever you want to it.....if you want to go inboard....were here for you.!...(btw..thats a nice boat)

i think it will be fun watching you do this and a great addition to the site.
im really looking foward to reading your posts.

cheers
oops

 

[oops!]

Re: Crestliner 17' O/B to I/O... Say Whaaaa?

now wait just a minit here......

i was just thinking about this in the shower.......

you said ....."plans have been on the drawing board for a year"

you said......"a very light 200 hp motor"

you have allready thought of the weight / space issue.....

are you thinking of going to a japanese type motor ....like you would find in a honda, toyota or mitsubishi car?

i mean get away from the standard mercruiser, chev/ford system?....the touque is less......but tremendous spin speed.

you would have to do a lot of fabbing........you would have to have the talent and money.....but it could be done .........i think......!!!!!!

if im wrong here.......dont pay any attention to what i just said....!!!!
dont even give it a second thought....!!!!....carry on the way you were going

but if im right.....................

cheers
oops

 

[RotaryRacer]

Re: Crestliner 17' O/B to I/O... Say Whaaaa?

http://www.atkinsrotarymarine.com/

hmmm?

 

[wca_tim]

Re: Crestliner 17' O/B to I/O... Say Whaaaa?

Doesn't the outboard vs. I/O depend a little on how you define performance and what you're looking for overall? Doesn't the average I/O do a good bit better on fuel economy than an equivalent outboard set-up? I know I can run my 4.3 I/O hard all day on a tank of gas playing and pulling skiiers, etc... None of the outboards I've owned that would have kept up would go that long on the same amount of gas. I also like the back of the boat open and clean without an outboard sticking up... Granted, some of the newer outboards change the picture a bit, but then again, I doubt you're thinking about spending 10 or 15 grand on the engine for this particular project...

 

[Ataraxia]

...She's gonna be a first!

...She's gonna be a first!

Thanks for the input and warm welcome, guys! I kinda knew I was going to have to explain myself a bit, lol

Opps!, your project is very inspiring and thats what finally made me post mine, knowing it's unconventional, and sometimes looked down upon. You could have just bought a larger boat but, what fun is that? Besides, you still want to make the layout the way YOU LIKE IT. as i am. My hat off to you sir.

Chris1956, do you know of many 200hp(more like 300+) 4-stroke outboards that weigh in the 400# range?

Opps! your last post hit the nail on the head. I'll elaborate. The alpha1 drive alone is not THAT heavy, we can pretty much say it's close to the weight of a LARGE outboard leg. Sure there is a gimbal assembly little hydraulic pump and a hand full of other bits that gets the weight up, but still.

Picture this... This little german engine is all about the TORQUE. it's a 2.8L V6, 19" long x 10 wide x 22" tall (not including sump, which sits 6" under the floor line. It's pretty freaking small huh? This v6 has the words smallest V angle piston arrangement. It has only one head with duel overhead cams. The torque this engine produces is amazing (especially low end).

Yup, it's the VW 2.8 v6 known as the VR6. As far as I know, this install will be a first! Mind you the 200HP i mentioned is without the supercharger kit bolted on... an instant, reliable 300Hp. I already have absolutely all the mechanical hardware. (no going back now, I'm committed, lol) You may all be surprised, but this project is quite easy on the wallet, considering how "involved" it is. Mind you, all of the fabrication and precision machining will be done by yours truly.


BTW, It probably helps a bit that I own a machine shop

 

[erikgreen]

Re: Crestliner 17' O/B to I/O... Say Whaaaa?

Post lotsa pictures here

It's nice to see someone who's not a beginner with a dream like this willing to give it a try... not that beginners are bad, but they don't know what they're getting into, and it sounds like you do.

You and oops are starting to inspire me.. I may tackle a scratch-built boat next fall, after boating season

Erik

 

[MikDee]

Re: Crestliner 17' O/B to I/O... Say Whaaaa?

Hey Ataraxia, Why don't you go with an Arneson surface drive? or something like that? It's more compact, lighter, less moving parts, and delivers more speed, with a nice rooster tail, But may not put out as much torque, I'm not sure?

 

[Ataraxia]

Re: Crestliner 17' O/B to I/O... Say Whaaaa?

WCA_Tim, you are right. I have had and still own outboards, and they are great but the fuel consumption on a large two strokes is brutal. You can't argue with the numbers.

Also performance and handling is just different (smoother?) when the main weight of the drive package is on the inside of the transom. Easy to work on, few proprietary components and so on... (well, my application may be slightly unorthodox )

I realize there will always be people out there like Chris1956 giving the big ol thumbs down to "out of the box" thinking, but thats ok. All criticisms are welcome and I absolutely encourage it. I'm not a naval engineer by any stretch, but a dreamer that has made a few dreams come true already. Takes time to gather all the research and to make the calculations to design something that is reliable, safe and fun! Being a little nutty also helps...



Indicated by the yellow arrow in the pic, this part extends almost 39". Now based on the transom wall where it meets the floor, the inner transom plate, custom bell housing and engine block (right to the farthest point being the crank pulley) will still sit closer than 30 inches... even with it's stainless water jacketed manifold, water/intercooled intake manifold and closed cooling system, it will still be WAY smaller than anything i have seen yet. even comparing it to a 4cyl Mercruiser 120 which looks huge compared to my setup. Beside the engine box will be floor. and about 12" of top, to the rear of the transom. Soon I will explain with pics and CAD illustrations.

Like I said there is no turning back. Although I wish it wasn't so friggn cold outside so I can start on it again!!!

 

[jcsercsa]

Re: Crestliner 17' O/B to I/O... Say Whaaaa?

OOOOOHHHHHH MAN I want to see this !!!! lol post lot of pics , please !!!!! dont they use kind of the same engines in the seadoos ??? man go for it !!! John

 

[Ataraxia]

Re: Crestliner 17' O/B to I/O... Say Whaaaa?

RotaryRacer, Thanks for the info. I have seen some nutty rotary inboard installs... Very impressive and a totally motivational for me

Erik, Good luck with your fall project. I too was going to scratch build, but it turned out easier and obviously cheaper to use an old hull as a template, and change up what you want on it. Besides, I am partial to my Crestliners (and my VW race cars ) so I just had to rescue this beauty. She's an ex-movie prop, that was going to be used by the local fire dept for training.... That would break my heart!!!

MikDee, I did look into surface drives, but for my application it just wouldn't be suitable. Realistically, this is going to be my multi season, fast ,fishing boat. I think surface drives are great for top speed and weight reduction, but they are kinda large. Merc outdrives are easy to service and find parts for. besides, I already bought a few alpha drives... no turning back. BTW i looked at your boats, that searay(?) you have is very inspiring. 224hp 19' doing 50mph? My top speed goal is 60mph, no more no less...(ok, more is always welcome)


Just for kicks, heres a little clip of the 14' stinger. She's my little workhorse!
http://ca.youtube.com/watch?v=XBc6exzV7h8

 

[MikDee]

Re: Crestliner 17' O/B to I/O... Say Whaaaa?

RotaryRacer, Thanks for the info. I have seen some nutty rotary inboard installs... Very impressive and a totally motivational for me

Erik, Good luck with your fall project. I too was going to scratch build, but it turned out easier and obviously cheaper to use an old hull as a template, and change up what you want on it. Besides, I am partial to my Crestliners (and my VW race cars ) so I just had to rescue this beauty. She's an ex-movie prop, that was going to be used by the local fire dept for training.... That would break my heart!!!

MikDee, I did look into surface drives, but for my application it just wouldn't be suitable. Realistically, this is going to be my multi season, fast ,fishing boat. I think surface drives are great for top speed and weight reduction, but they are kinda large. Merc outdrives are easy to service and find parts for. besides, I already bought a few alpha drives... no turning back. BTW i looked at your boats, that searay(?) you have is very inspiring. 224hp 19' doing 50mph? My top speed goal is 60mph, no more no less...(ok, more is always welcome)


Just for kicks, heres a little clip of the 14' stinger. She's my little workhorse!
http://ca.youtube.com/watch?v=XBc6exzV7h8

I see, well good luck then, interesting project, I admire people who think out of the box, Nice boats by the way,,, That 14 footer zips along nicely too. By the way, I figure my 20' Searay would have done 55mph with a 350/260hp, and 60mph with the standard 454/330hp at the time, but I didn't have the time, energy, or money to do either. If you can get 300hp, in that light engine pkge, you might see 60, I'd bet 55 at least!

 

[Chris1956]

Re: Crestliner 17' O/B to I/O... Say Whaaaa?

Ataraxia, OK, so now you say 300HP 4 cycle motor. Your original post said 200HP. A 200HP 2 cycle outboard can be had for <500#, as could a 250HP OB.

Your original post also did not explain that you can fabricate custom water cooled mainfolds, and were willing to spend large sums of money on exotic (I presume exotic=large sums of money), light compact power. I suppose you can custom-make the Alpha I coupler and engine adaptor? You are aware that MerCruiser uses Brovo drives with 300HP!

OK, other than the unusualness of the design, what are it's advantages? You can buy a lot of outboard fuel for the cost and work differential...

 

[oops!]

Re: Crestliner 17' O/B to I/O... Say Whaaaa?

ataraxia....


i can tell allready.....we think very simmelar....we're gonna get along...just fiiiiiine...!
and...as far as being a dreamer that made a few dreams come true.....thats what makes the world progress.....i too have had dreams...and built them...

actually when i said i was thinking about it in the shower.....what i really ment was.....i got so excited about your project....i jumped out of the shower dripping wet ...ran to the computer...typed that post while dripping all over the puter.....

big thumbs up to ya...!!!
i was thinking of somthing like that but i dont have the talent or resources to do the fabbing on the parts.....


and btw...you also said it was cold out side.....what area are you in?

as far as the bravo/alpha thing...it is generly accepted that the hp line for the alpha is 300....it has worked above 300..330 i think...but must be handled a little softer
i think your 60 mph is easily attainable with what your doing....i think you might find it to be a little more...

keep us posted

cheers
oops

 

[Willyclay]

Re: Crestliner 17' O/B to I/O... Say Whaaaa?

I always thought the old Buick aluminum V-8 (215c.i.) that was purchased by Land Rover would make a good lightweight marine engine if you could overcome the exhaust manifold issue. Good luck with your project!

 

[wca_tim]

Re: Crestliner 17' O/B to I/O... Say Whaaaa?

.....i got so excited about your project....i jumped out of the shower dripping wet ...ran to the computer...typed that post while dripping all over the puter.....

Dude! Thanks a lot for the mental image (NOT). That is just soooo wrong....

 

[oops!]

Re: Crestliner 17' O/B to I/O... Say Whaaaa?

Dude! Thanks a lot for the mental image (NOT). That is just soooo wrong....

lol....lmao.... ....my girl is looking at me all weird like....as im sitting here splitting a gut at the puter

 

[jcsercsa]

Re: Crestliner 17' O/B to I/O... Say Whaaaa?

Dude! Thanks a lot for the mental image (NOT). That is just soooo wrong....

OOOOPS THAT was just so wrong !!!!! hahahahaha so wrong !!!! John lol and look at me life short boat Naked !!!! lol

 

[Ataraxia]

Re: Crestliner 17' O/B to I/O... Say Whaaaa?

Ataraxia, OK, so now you say 300HP 4 cycle motor. Your original post said 200HP. A 200HP 2 cycle outboard can be had for <500#, as could a 250HP OB.

Your original post also did not explain that you can fabricate custom water cooled mainfolds, and were willing to spend large sums of money on exotic (I presume exotic=large sums of money), light compact power. I suppose you can custom-make the Alpha I coupler and engine adaptor? You are aware that MerCruiser uses Brovo drives with 300HP!

OK, other than the unusualness of the design, what are it's advantages? You can buy a lot of outboard fuel for the cost and work differential...

Chris1956, obviously you are quite knowledgeable with boats and drive systems. Let me say that I can only hope to absorb as much as possible from your wisdom and "common sense approach" to boating and good old "tried and tested" general marine knowhow. I still consider myself young and ambitious enough to tackle a project as "exotic" as it may sound. So far the data you have provided me with is very interesting and to be honest, very encouraging. I will always value your input.

Here's the thing, I'm just not 100% sure if you understand the concept of THIS project that I am sharing with the forum. I will try to answer your questions as best as I can. Like I said, I'm no naval engineer, and I may not have a post count of over 4000 (more like 5, lol) so my terminology may not be text book accurate, but like I always say, you can not judge a man and his capabilities by his post count, only his free time . Hopefully, maybe, my project may interest/educate some people out there that also have crazy dreams. (ohhh there are many of us crazies out there, eh? )

So here goes... Yup, I'm capable of making the bellhousing. To be honest, the custom bellhousing/adapter is probably the easiest part that requires precision machining. Am I aware of the mercruiser family of sterndrives, HP capabilities and internal weaknesses? You bet . Also I apologize for not stating in my original post that I can manufacture things. (that matters?)

Advantages of this design... First and most important, I'm doing this because I can (really! ). The hull will be fitted with (some composite construction) a seriously lightened stringer grid system, including every structure built into this boat. Kinda like Jenny Craig, for chubby ol deep V's that never had a chance in hell to exceed in performance with generic overweight and underpowered engine/drive packages. The advantages out weigh the disadvantages.