Seized Engine

John 76

New member
Joined
29 Apr 2014
Messages
6
Visit site
I am new to all this so apologies in advance for my lack of knowledge!

I have acquired a 25ft Sundancer with a seized engine and I have a couple of questions which I am really struggling with:

1. What could I expect to be charged to strip and rebuild the engine?
2. Is it worth doing this?
3. If I bought a new engine, what could I expect to pay for its installation?

Thanks in advance,

John

PS it is a Mercruiser 5.7 litre, V8, 210hp petrol inboard engine if that helps! Like I say, I know nothing!!
 

krbp32

New member
Joined
27 Apr 2014
Messages
18
Location
West Midlands
Visit site
Plenty of bargains on fleabay. Any idea what sort of seize it is ? If it has been standing a long time it could be condensation in bores seizing the rings. If its the crank thats a different matter :ambivalence:
 

crazy4557

Member
Joined
3 Aug 2008
Messages
954
Location
Lymington
Visit site
If I was doing this I would go for a new engine. Nothing wrong with rebuilt units but you're relying on one sole engine to get you home every time you go to sea. A new engine would be a far more reliable proposition even though it will cost considerably more but gives you peace of mind and also a higher resale value and easier to sell when the time comes.
 

wipe_out

Active member
Joined
23 Feb 2013
Messages
1,399
Location
Bournemouth
Visit site
We replaced our 5.7L last year with one of these from Repower Marine. http://repower-marine.com/marine-en...vo-penta-v8/brand-new-5-7l-advanced-base.html (Difference is ours has the Holley 4BBL carb)

We decided to do a full engine including manifolds and carb because we didn't know the condition of the old carb and it was really a better option for the piece of mind knowing it was all new.. We replaced the exhaust manifolds and risers as well because failure here often means you trash the engine..

Depending on how you feel you can get one of their less complete units starting at £3000 and use the parts from the old engine.. http://repower-marine.com/marine-engines/replacement-mercruiser-engines/repower-mercruiser-v8

As for installing it you are looking at a couple of days labour at least.. I would say budget around £1500 to have it done or if you're handy with a spanner and have the time you might be able to do it yourself..
 

vyv_cox

Well-known member
Joined
16 May 2001
Messages
25,861
Location
France, sailing Aegean Sea.
coxeng.co.uk
Many years ago i bought an MG saloon car of 1938 vintage. It had a seized 6 cylinder engine and had not run for years. The only cause of seizure was that the rings were rusted to the bores. I stripped the engine and was able to move the pistons by light tapping using a wooden block and hammer after applying paraffin. Once the pistons were out they and the rings were found to be in reasonable condition. I dressed the bores using a flap sander, reassembled and the engine ran fine.
 

oldgit

Well-known member
Joined
6 Nov 2001
Messages
28,249
Location
Medway
Visit site
Do not forget the check your outdrive while boat is out of water, drain drive oil and check for water ingress .
Replace rubber bellows i Check rams raise and lower leg without drama.
If a milky foamy mess dribbles out of gearbox you need to find out how water has got in.
Mostly easy to fix stuff such as seals bellows etc are well within the remit of most DIYers and have to be done with boat out of water.
Do not assume anything has been done by previous owner, if that engine seized a while ago, the old owner has probably declined to spend any further money on anything at all.
 

John 76

New member
Joined
29 Apr 2014
Messages
6
Visit site
Thanks for the advice.

Do not forget the check your outdrive while boat is out of water, drain drive oil and check for water ingress .
Replace rubber bellows i Check rams raise and lower leg without drama.
If a milky foamy mess dribbles out of gearbox you need to find out how water has got in.
Mostly easy to fix stuff such as seals bellows etc are well within the remit of most DIYers and have to be done with boat out of water.
Do not assume anything has been done by previous owner, if that engine seized a while ago, the old owner has probably declined to spend any further money on anything at all.

Knowing nothing about engines myself I would have gone in and been whacked with a huge bill. Thank you!
 
Top