Mercruiser 305 engine - water corrosion - what is cheapest/best solution

[slickcraft305]

Hi there. I am a newbee here so I hope this is the right place to ask. I have had a slickcraft from 1979 with a Mercruiser 898 V8 305 engine with 228 hp. After a faulty repair from a mechanic who did not know what he was doing, the boat has been in water - and now the engine has taking in water and corroded the engine Situation is now, that we have taken off the top of the engine and it looks nasty inside. The right side looks "okay" and the left side looks terrible. On this forum many people are saying that if a 305 engine brakes, I should be a 350 engine and install this. But since I not quit motivated for spending so much money I am looking for advise how to prioritize. Here is my dilemma?s I hope some of you will comment on to help me in the right direction.

1. the mechanic who helped me taking the top of to see inside (not marine mechanic) has told me he can repair the engine for about 100 working hours + parts
2. should I send the engine to a "overhaul" place to restore it
3. Is it not worth the effort - and should buy a 350 instead.
4. To be honest I am not looking for more power - actually it would be fine to install a smaller engine - unless it will complicated things with fittings and all.

Hope for some advise from you good people out there.

I have made a folder with photos to see: https://www.dropbox.com/sh/v3bhf9joe3b2pe4/AAA1pjK8QYTd6-65K1Oy0S3Aa?dl=0

 

[Scott Danforth]

welcome aboard

FYI - no-one likes clicking links to go look at pictures. we just dont do it here is the photo upload tutorial. use option #3

http://forums.iboats.com/forum/forum...pload-tutorial

at a mechanic rate of 100 hours plus parts, rebuilding your nasty rusted motor will cost nearly the same as buying a new long block. if you buy new, buying a 4.3 is about the same cost as a 305 which is the same cost as a 350. Reman is about $2300, New is about $2800. if your motor wasnt rusty in side, then rebuilding at a reputable machine shop would cost you about $1800-2000 (new pistons and rings, rods, bearings, gaskets, crank turned, block line-honed, bored, honed, decked, balanced)

if you do not have the cash handy to rebuild your motor, buy a reman or new long block, go to your local salvage yard, pull a low mileage and running 305 or 350 from any 1985 or older pickup truck (to match your current flywheel and coupler). replace the head gaskets with marine. replace the block core plugs with brass or stainless. now transfer your oil pan, dipstick, circulating pump, alternator, starter, etc. from the old motor to the new motor

if your exhaust manifolds were the reason your motor was full of water, then throw them away and buy new manifolds and risers.

the cheapest solution is get a running motor from a 1985 or older pickup truck
the best solution is to get a complete long-tail and replace everything from the carb to prop. this is also the most expensive solution

 

[Jcris]

If I were in your spot, I would do most to the work myself. Are you willing/capable of doing that? Give some thought to how much you're willing to spend to get this fixed? Is this boat worth it? I really don't mean to be difficult and it does appear to be a decent boat. But......

 

[Bondo]

3. Is it not worth the effort -

Ayuh,.... Welcome Aboard,.... That might be a distinct possibility,...

To get it runnin', 'n on the water,...
Take Scotts advice, 'n find a used runnin' long block motor from a pickup or sedan of that vintage,...
Then swap the salvageable marine components from yer motor, 'n put 'em on the used long block,...

For abit nicer, probably reasonably priced option,....
Find a used take-out boat motor 305, 350 or a 4.3l, if fully dressed,....
They'll bolt in between their parts, 'n yer old parts,...
A rotten hull donor boat is where those motors are found,....

'n probably the Best option for yer sweet lookin' hull,....
Update it's entire driveline to current production models with a donor boat swap,....

Oh,... in the video of it runnin' in the water,..?? that's Full up tilt,....
Never start a motor with the drive that high,....
It tears out the u-joints, 'n bellows,....

 

[slickcraft305]

welcome aboard

FYI - no-one likes clicking links to go look at pictures. we just dont do it here is the photo upload tutorial. use option #3

http://forums.iboats.com/forum/forum...pload-tutorial

at a mechanic rate of 100 hours plus parts, rebuilding your nasty rusted motor will cost nearly the same as buying a new long block. if you buy new, buying a 4.3 is about the same cost as a 305 which is the same cost as a 350. Reman is about $2300, New is about $2800. if your motor wasnt rusty in side, then rebuilding at a reputable machine shop would cost you about $1800-2000 (new pistons and rings, rods, bearings, gaskets, crank turned, block line-honed, bored, honed, decked, balanced)

if you do not have the cash handy to rebuild your motor, buy a reman or new long block, go to your local salvage yard, pull a low mileage and running 305 or 350 from any 1985 or older pickup truck (to match your current flywheel and coupler). replace the head gaskets with marine. replace the block core plugs with brass or stainless. now transfer your oil pan, dipstick, circulating pump, alternator, starter, etc. from the old motor to the new motor

if your exhaust manifolds were the reason your motor was full of water, then throw them away and buy new manifolds and risers.

the cheapest solution is get a running motor from a 1985 or older pickup truck
the best solution is to get a complete long-tail and replace everything from the carb to prop. this is also the most expensive solution

HI and thanks for replying...apologies with the link to photos - point taken.

After reading much about this issues, I am not not surprised to hear that buying a god used engine would be almost same price as repairing the old (depending how serious my engine is damaged..,cant really judge - besides it looks ugly). I have a guy who can help me with all the mechanics, so finding a running motor from an older pickup could be an option. Challenge is that I live in Denmark - and have almost no access to pickup trucks or chevy?s so the vintage market is rather limited.

Just one thing - people are talking about buying a long block engine - I presume I have a small block engine ., Sry for the dummy-question, but can you guys confirm this for me ?

Last, if I am looking for another engine - how much is "too many miles on the clock" - or year ? - any directions here ?

Thanks for helping me out here.

 

[slickcraft305]

If I were in your spot, I would do most to the work myself. Are you willing/capable of doing that? Give some thought to how much you're willing to spend to get this fixed? Is this boat worth it? I really don't mean to be difficult and it does appear to be a decent boat. But......

Thanks for commenting...no I am not capable of doing the repairs my selv, but I have a good auto mechanic friend who would like to help me out.
I think I can spend about $2500-3000 tops

 

[slickcraft305]

Ayuh,.... Welcome Aboard,.... That might be a distinct possibility,...

To get it runnin', 'n on the water,...
Take Scotts advice, 'n find a used runnin' long block motor from a pickup or sedan of that vintage,...
Then swap the salvageable marine components from yer motor, 'n put 'em on the used long block,...

For abit nicer, probably reasonably priced option,....
Find a used take-out boat motor 305, 350 or a 4.3l, if fully dressed,....
They'll bolt in between their parts, 'n yer old parts,...
A rotten hull donor boat is where those motors are found,....

'n probably the Best option for yer sweet lookin' hull,....
Update it's entire driveline to current production models with a donor boat swap,....

Oh,... in the video of it runnin' in the water,..?? that's Full up tilt,....
Never start a motor with the drive that high,....
It tears out the u-joints, 'n bellows,....

Yes I will see if I can find an running block - but I need a small block and not a long block..right ?
The video with the engine running is with the boat in water...I guess you mean that I damage u-joints etc.. when the drive is not in the water when I start up engine ? - just so I understand this correctly ?

thanks

 

[Scott Danforth]

you have a small block chevrolet, and a 1985 or older would be best to fit with the flywheel and coupler you have

a short block is the block, with crank, pistons, rod, etc. A long block is a short block with heads on it. you need a good running long block, or a complete 1985 or older bob-tail mercruiser marine motor (fully dressed from carb to flywheel housing - without the outdrive or transom shield. you can use any long-tail mercruiser marine motor (complete from carb to prop)

if your looking to spend $2-3k tops and you live in Denmark, you're going to have to be creative. you would spend that here in the US.

 

[slickcraft305]

you have a small block chevrolet, and a 1985 or older would be best to fit with the flywheel and coupler you have

a short block is the block, with crank, pistons, rod, etc. A long block is a short block with heads on it. you need a good running long block, or a complete 1985 or older bob-tail mercruiser marine motor (fully dressed from carb to flywheel housing - without the outdrive or transom shield. you can use any long-tail mercruiser marine motor (complete from carb to prop)

if your looking to spend $2-3k tops and you live in Denmark, you're going to have to be creative. you would spend that here in the US.

OK. thanks for clarifying this - guess I need to be creative here and will try to look into more options. Are there other engine (smaller that would fit - or is it only the 350 which fits easily without any modifications or fittings ?

 

[Scott Danforth]

the 305 and 350 from 1978-1985 would be the easiest to drop in if you just got a longblock. however any mercruiser 5.0 or 5.7 bobtail would work. just find a boat that got damaged

you can also look at volvo-penta powered boats for a used motor as they also used the GM 305 and 350