blew outboard, fix it or go inboard. have big block waiting!

[muddinmike]

I have a 78 18' tahiti with a 140 merc on the back. carrier bearing in the bottom end seized up and broke the drive shaft off in the crankshaft. the mechanic i took it to said it was 2400 for a rebuilt lower end plus labor. I have a automotive ford 460 thats pretty much brand new i bought for another project that i canned. I also can get a jet pump for 700 bucks. im thinking that is the best route to go for me. is there any guides to how to mount a motor in a boat that used to be a outboard? or do you guys have a source for old boat parts to fix my outboard? Im a complete newb to boats by the way. will the big block be too heavy for the lil tahiti? I know im going to loose some interior space and that doesnt concern me.

 

[proshadetree]

Re: blew outboard, fix it or go inboard. have big block waiting!

There are some smart ppl here http://sidewinder-boats.com/portal/windertalk/index.php But make no mistake changing an outboard to an inboard is a major job.The front of the baot is the same its the back that must be redone altogether.If it were me and I needed funds Id sell inboard stuff to fix or replace your old outboard.Tahiti came with big blocks and small blocks.Youll have to cut out floor most of the back of boat make engine mounts hole in transome all must be lined up I mean a major undertaking.Have you looked on e bay for lower unit for what you got?

 

[Chris1956]

Re: blew outboard, fix it or go inboard. have big block waiting!

Mike, You can pickup a used lower unit for that motor of <$500. If it is a 70s inline six, I have one for less than that.

If you drop a big block motor into an 18' boat the weight change alone will be staggering, as you OB likely weighed 300# and a big block sterndrive weighs 1500# or so.

 

[tashasdaddy]

Re: blew outboard, fix it or go inboard. have big block waiting!

automotive ford 460 will have to be marinized, there are strick coast guard regulations.

 

[oops!]

Re: blew outboard, fix it or go inboard. have big block waiting!

automotive ford 460 will have to be marinized, there are strick coast guard regulations.

ill elaborate on this ......

to marinize a car motor....you need a new cam, dist, starter, alternator, flame arrestor for carb. water seperator, some type of cooling for the motor, uasually that includes manifolds, or a raw water pump with some type of heat exchanger.

just about every item on that list is expencive.....

then you have to prep the boat......beef the transom.....add a proper bilge area.....motor mounts....then glass that all in and uasually gellcoat the bilge area.

then you have to build an engine doghouse. ect...ect...ect.

if you just wanna go fishin or boating.....go with the outboard.....i/o are a ton of work for maintenince after they are installed....ob's are easy

its been done before with sucess......just depends on the dollar figure your loooking at.....2200 would not cover the cost of conversion unless you get really lucky

 

[NoKlu]

Re: blew outboard, fix it or go inboard. have big block waiting!

Got a friend that just bought a jet boat[Eagle racing hull with an american jet] with a stock 460 ford. The 460 is a work horse motor not the powerhouse you might want. It'll drink a lot of fuel and run all day and night without missing a beat but you'll get passed by almost all newer runabouts. Unless it's modified to turn 6000 rpm you will be disappointed with it in a jet boat. That's his project for the winter.

 

[109jb]

Re: blew outboard, fix it or go inboard. have big block waiting!

Let's see:

Rebuild outboard = $2400 + a few hundred for labor, no headaches, no boat mods, no other problems, no work for you. little down time, turn key and go. Can also be done much cheaper by finding a good used lower unit. Could knock $2k off your total.

Inboard with auto engine = at least that much money if you do everything yourself, much more if you pay someone else. Lots of work, lots of boat mods, potential teething pain problems, lots of work for you to keep cost down, lots of down time.

You can do what you want, but in my opinion, you are better of fixing your outboard even if it does cost you $2400.

BTW, my brother in law just bought a 1995 150 merc outboard in great running condition for $1500. Hell, I just bought a 1997 115 Mariner for $2000, and it came with a boat and a trailer for no extra cost.

 

[Rich Hargis]

Re: blew outboard, fix it or go inboard. have big block waiting!

Go to the big auction site (yabe) Backwards.There is always a lower unit for sale.

 

[muddinmike]

Re: blew outboard, fix it or go inboard. have big block waiting!

thinks for the opinions. definatly seems cheaper to fix the out board with some used parts. the clowns in the shop told me 2800 to 3800 to put a new lower end on it.

 

[NSBCraig]

Re: blew outboard, fix it or go inboard. have big block waiting!

Yeah I love the idea of doing the swap but I'd pass and fix the outboard even if only for the reason you're not going to be happy with the performance of the 460/jet combo.

It takes over 600hp to make a jet boat run as fast as a decent outboard that you could buy for under $1,000.

Maybe if you use a outdrive but don't waste your money building a jet it would be cheaper to buy one then build one.