Buying boat with broken engine (Perkins 100 series 103.09)

[Spirit (of Glenans)]

If the piston rings are worn to the point where the engine won't run, then you have to assume that the bores are worn (so will need a rebore and oversized pistons/rings, that the crank will need honing and new bearing shells fitted, and all the seals replaced. If you can't do this yourself, it will be cheaper to fit a new engine. £5k.

Plus a new oil pump.

 

[Spirit (of Glenans)]

My thoughts as well, how does he know piston rings are no good?

Burning oil?

 

[ChromeDome]

Just a general hint:

Before anything, make your budgets for investment (purchase + necessary repairs) and operation. The value of the boat, when ready, should match the market price of one in similar condition (give 'n take).

The intangible asset/risk of investing in something you have no clue about how ends, should be factored in also.

If you go, the options are repair, replace with used or trade for a new. If getting another engine with same rpm/torque characteristics the gearbox and prop may be reused, if fitting something different you'd need to change these.
Then add changes to the engine bay, connections to power/fuel/cooling/exhaust, cabling to remote controls and harness to the instrument cluster (which should come with the engine - if not it is just another cost).

If looking for a "just add water" boat you'd need to search on.

 

[Beneteau381]

Burning oil?

worn valve guides? anyway the description was "broken engine" so more drastic than burning oil?

 

[Spirit (of Glenans)]

worn valve guides? anyway the description was "broken engine" so more drastic than burning oil?

I was proposing an answer to Beneteau381's question; "How does he (the vendor) know the piston rings are broken?"
Blue smoke from burning oil (plus a loss in compression) are the most obvious symptoms of an engine burning oil which is entering the cylinders past the broken rings.
Worn valve guides would result in some loss of compression, which in would in turn result in the space under the rocker cover becoming pressurised, and oil-laden exhaust gas being expelled through the engine breather.

 

[Beneteau381]

I was proposing an answer to Beneteau381's question; "How does he (the vendor) know the piston rings are broken?"
Blue smoke from burning oil (plus a loss in compression) are the most obvious symptoms of an engine burning oil which is entering the cylinders past the broken rings.
Worn valve guides would result in some loss of compression, which in would in turn result in the space under the rocker cover becoming pressurised, and oil-laden exhaust gas being expelled through the engine breather.

Worn valve guides allow oil to pass in to the cylinder and be burned, they dont result in loss of compression,

 

[vyv_cox]

I once bought an Alfa Romeo with its engine in boxes in the boot. It took a lot of work (by me) to repair and install it but well worth it in the end. I learned a lot while doing it.

 

[ylop]

So, to the OP, I guess what you're really getting as feedback here, is that you should be looking to get the boat cheap. Not £10k off, because with a new engine, the boat will be worth more, but I guess it has to be a bit chunk of it to make it worth buying.

Actually, I'd say in a normal market it is worth 10k less than the same boat with the old engine in good running order. On top of the cash cost the buyer has the hassle of dealing with the mechanics, the time the boat is "off the water" etc. If the seller believes its "only" a "simple" job of changing the piston rings (costing say £2-3k) then he should do that job and sell the boat in full working order. Otherwise he's selling a "project". In fact depending on where its kept and how you feel about sailing without a test sail you may be buying blind about any rigging issues etc too.

HOWEVER, assuming the market is still as bonkers as the 2020/2021/2022 then some other idiot will be prepared to pay over the odds for it. If you really want that boat you'll have to pay over the odds too. For me it would be a walk away as there are almost certainly other boats for similar money without the hassle.

Some points to beware of with the suggested "get a tractor mechanic":
1. If its in a marina / boat yard some are rather restrictive on who can turn up and work on a boat.
2. The tractor mechanic may well take one look and realise working on boats is a job for contortionists and put the price up / walk away. If paying by the hour a boat mechanic might be quicker having learned some little tricks for getting stuff in spaces that are too small.
3. For something like a reengine or rebuild most tractor mechanics will expect the tractor to come to them. You may be paying travel time unless they are desperate for work.
4. If your tractor mechanic is not used to the nuances of boat engines, there are places to make mistakes - and some simple things like double clamping cooling water seacocks could be rather important.

 

[geem]

Actually, I'd say in a normal market it is worth 10k less than the same boat with the old engine in good running order. On top of the cash cost the buyer has the hassle of dealing with the mechanics, the time the boat is "off the water" etc. If the seller believes its "only" a "simple" job of changing the piston rings (costing say £2-3k) then he should do that job and sell the boat in full working order. Otherwise he's selling a "project". In fact depending on where its kept and how you feel about sailing without a test sail you may be buying blind about any rigging issues etc too.

HOWEVER, assuming the market is still as bonkers as the 2020/2021/2022 then some other idiot will be prepared to pay over the odds for it. If you really want that boat you'll have to pay over the odds too. For me it would be a walk away as there are almost certainly other boats for similar money without the hassle.

Some points to beware of with the suggested "get a tractor mechanic":
1. If its in a marina / boat yard some are rather restrictive on who can turn up and work on a boat.
2. The tractor mechanic may well take one look and realise working on boats is a job for contortionists and put the price up / walk away. If paying by the hour a boat mechanic might be quicker having learned some little tricks for getting stuff in spaces that are too small.
3. For something like a reengine or rebuild most tractor mechanics will expect the tractor to come to them. You may be paying travel time unless they are desperate for work.
4. If your tractor mechanic is not used to the nuances of boat engines, there are places to make mistakes - and some simple things like double clamping cooling water seacocks could be rather important.

Just take the engine out and deliver to the tractor mechanic. Far easier when the whole engine sounds like it needs stripping to see what's wrong. There may be other stuff worth replacing as well. If you can knock sufficient money off the boat then worth a punt if you are a Practical Boat Owner?

 

[ylop]

Just take the engine out and deliver to the tractor mechanic. Far easier when the whole engine sounds like it needs stripping to see what's wrong. There may be other stuff worth replacing as well. If you can knock sufficient money off the boat then worth a punt if you are a Practical Boat Owner?

Yes - but then you have the job of removing the old engine and refitting it afterwards. Its not brain surgery but its probably a full day* to remove it and I'm guessing longer to reinstall it. Perhaps an experienced mechanic (especially one used to the challenges of working on boats) can do it quicker. If this was really a simple job the vendor would have fixed it.

*and many jobs that I think are a full day often turn into a full weekend...

 

[geem]

Yes - but then you have the job of removing the old engine and refitting it afterwards. Its not brain surgery but its probably a full day* to remove it and I'm guessing longer to reinstall it. Perhaps an experienced mechanic (especially one used to the challenges of working on boats) can do it quicker. If this was really a simple job the vendor would have fixed it.

*and many jobs that I think are a full day often turn into a full weekend...

I used to be able to get my 35hp Yanmar engine and gearbox out of my Prout Snowgoose in 2 hours. Undo the engine mounts, prop shaft, morse cables, electrics and lift. It was easy having a hatch over the engine and a boom to lift on but it's not hard or technical stuff.
Do you know the vendor? How do you know 'if it was easy the vendor would have fixed it'. He could be old and hanging up his sailing boots. He may not be practical or even diagnosed what is actually wrong with the engine. If you can knock off sufficient money from the purchase then its still worth a punt.
Once you have stripped and checked and replaced all work parts you know you have a good viable engine that you can rely on

 

[Beneteau381]

I used to be able to get my 35hp Yanmar engine and gearbox out of my Prout Snowgoose in 2 hours. Undo the engine mounts, prop shaft, morse cables, electrics and lift. It was easy having a hatch over the engine and a boom to lift on but it's not hard or technical stuff.
Do you know the vendor? How do you know 'if it was easy the vendor would have fixed it'. He could be old and hanging up his sailing boots. He may not be practical or even diagnosed what is actually wrong with the engine. If you can knock off sufficient money from the purchase then its still worth a punt.
Once you have stripped and checked and replaced all work parts you know you have a good viable engine that you can rely on

Indeed and the description "engine broken" needs "piston rings" a bit glib. What is needed is definitive evidence of what exactly is wrong with it? Needs someone like me or Geem to go along and give a definitive answer. if the OP really likes the boat, then a written report by an expert is needed to help make a decision.

 

[geem]

Indeed and the description "engine broken" needs "piston rings" a bit glib. What is needed is definitive evidence of what exactly is wrong with it? Needs someone like me or Geem to go along and give a definitive answer. if the OP really likes the boat, then a written report by an expert is needed to help make a decision.

I think I would send you along?

 

[Tranona]

Just take the engine out and deliver to the tractor mechanic. Far easier when the whole engine sounds like it needs stripping to see what's wrong. There may be other stuff worth replacing as well. If you can knock sufficient money off the boat then worth a punt if you are a Practical Boat Owner?

The last bit is the crunch as I explained earlier. While a direct removal and replace is usually straightforward, less than a day's work with an engine like the one the OP is looking at, once you start paying somebody including often travelling time and labour rates of £50+ an hour in the UK costs soon mount up. It is rare with a 30 year old boat that you don't find other bits that need replacing and if stripping down and overhauling there is taking back to the workshop, stripping down, cleaning, possibly machining, hence the estimates I had as explained in post#4.

The OP clearly stated that he would have to pay somebody to fix it so unless the boat is otherwise desirable and priced such that the overall cost would be within what he considered good value, best to walk away. Of course another buyer capable off and prepared to do the work himself may take a different view.

 

[Spirit (of Glenans)]

Worn valve guides allow oil to pass in to the cylinder and be burned, they dont result in loss of compression,

Where does the pressure in rocker cover area come from then?

 

[geem]

The last bit is the crunch as I explained earlier. While a direct removal and replace is usually straightforward, less than a day's work with an engine like the one the OP is looking at, once you start paying somebody including often travelling time and labour rates of £50+ an hour in the UK costs soon mount up. It is rare with a 30 year old boat that you don't find other bits that need replacing and if stripping down and overhauling there is taking back to the workshop, stripping down, cleaning, possibly machining, hence the estimates I had as explained in post#4.

The OP clearly stated that he would have to pay somebody to fix it so unless the boat is otherwise desirable and priced such that the overall cost would be within what he considered good value, best to walk away. Of course another buyer capable off and prepared to do the work himself may take a different view.

He says in his opening post that he would have to pay somebody to do a rebuild. Nothing about not being able to remove the lump himelf. Once the engine is out and on somebodies bench to strip and check it the cost may be reasonable. If you can knock off enough money off the asking price for a new engine you are still left with enough money to go that route as well if the engine is terminal. If you can't get the boat for the right money in the first place then walk away.

 

[Beneteau381]

Where does the pressure in rocker cover area come from then?

Bypass from the pistons in to the crank case which pressurizes the internal spaces including the rocker box up the pushrod area.
A fundemental understanding of how an ic engine works will show that the compression is formed when the pistons push air and burning fuel against closed valves. The valve guides are on the other side.

 

[Spirit (of Glenans)]

Bypass from the pistons in to the crank case which pressurizes the internal spaces including the rocker box up the pushrod area.
A fundemental understanding of how an ic engine works will show that the compression is formed when the pistons push air and burning fuel against closed valves. The valve guides are on the other side.

Of course. The valves are closed on the compression stroke. It's all coming back to me now?