outboard as in inboard?

outboard as an inboard?

I am new to boating...but i was wondering if most outboard engines are water cooled, and if so could one be used as an inboard...
The purpose for this is that i find most outboards approximately 60-65 hp to be cheaper that inboard of the same power... My plan was to take the motor... mount it horizontally and have the driveshaft lead to the prop below the boat...usual mounting procedure for an inboard... Any advice on this, if it is possible would help me out a bunch, thanx guys.

 

Genius?

You are either a genius or out of your mind. I can't decide which.

 

ob inboard mounting, shaft, hullfittings and hoses, venting etc has still a better price?
need smal high tech block it would be, i dont know what to say...

 

cooling?

Guess my first question is a little out there.... can someone tell me if outboards are water cooled... maybe the rest i can try and figure out on my own. Thanx

 

Yup.

Even after buying transmission, shaft, strut, stuffing box, cutlass bearing, through hull fitting, seacock, hose, clamps.....? Mercury has jet drives with outboard powerheads mounted inboard (large SeaDoos)

 

I think so, yes. I belive they pull the water thru the ports on the lower unit so if you replaced that with a drive shaft, rerouting the plumbing would be an issue.( If I'm wrong someone help me. Builder not a rigger The mercury sportjet line uses an outboard powerhead to drive the jet, so I guess it is possible. My question is with the exorbitant cost of outboard motors these days is it really cost effective? Not to mention the terrible fuel economy. (fourstrokes not included) Its been a while since I made any comparisons but I think a new 60hp merc is about $4500 as opposed to a 355hp GM ZZ-4 crate motor V8 at around $3800/ V-6 about $2900 @ 250hp. Of course there are a lot of other factors that could even things out, I.E. weight to hp ratio, Fuel economy, ease of application, servicing(who will work on it when it breaks down) boating application. etc. etc. Mercury's sportjet has a voracious fuel appetite. On the other hand, you might be on to something. Inboard jets are really performing these days, but 200 hp outboard bass boats are hitting 90 mph. Dont outboards leak when layed over past a certain angle. Or is that just my '67 EvinrudeWho Knows.

Good Luck, Joey

 

What Inboard?

So the whole outboard as an inboard was a bad idea... but can someone suggest a cheap inboard...if that is the cost effective way to do it... same 60-65 hp for an old wooden runabout type of craft? It's a pretty small craft about 14 and a half ft. Thank you.

 

Why not a conventional outboard mounting?

 

Find yourself a second hand Mercruiser GM 4 cylinder sans outdrive, get an old Velvet Drive transmission (with bell housing), a new drive plate, and flywheel from a 305 or 350 with aft facing ring gear, and the top mount starter (make sure it's left hand rotation) and you'll be off and running for probably less than $3,000. The 4 cylinder GMs (older models) have the exact same bell housing flange as V8s so these parts should be easy to find. They're also internally balanced, so the flywheel swap is no problem, just avoid 454 flywheels, these are externally balanced. I got a used flywheel off E-Bay for $40. Good luck!

 

This is an interesting topic.

I have wondered if I could find a water cooled 40-60 hp gas engine that could be mounted in the cosole of a skiff, fitted to a jet drive. I havent been able to find a small v-twin (or other) liquid cooled engine over 35 or so hp.

 

Would the small wooden runabout be able to handle the 4 cylinder...I just don't want to put something into it that it won't be able to handle.
Thank you for the advice

 

Is it a planing hull? What type of construction, plank on frame....? What powered her originally? I think she should handle the 4 banger if she's well built and in good condition. If you want to go really small there isn't too much to choose from in gas engines, and even less ways to get the power to the prop. Possibly an old Atomic 4 from a sailboat. Don't know the HP, but they came in some relatively small sailboats. Google Atomic 4 and you can find out more about them. I don't believe they're in production anymore, so parts may be an issue.

 

The boat is a sea scout from svensons plans. Built pretty much unchanged from the plans.

 

How about diesel?

 

Yanmar has small diesels, Cummins/Mercruiser are coming out with a 1.7 liter that would fit the bill. I thought you were budget minded, sorry. These diesels will cost you as much or more than an outboard though.