Reoccurring Engine Failure / Deisel Problem

[wheels 543]

Don't waste your money on those Magnetic filters.They are a complete waste of time and money. A magnetic field does not, can not, instantly Kill Bug and even more, it simply can not tear it apart and make it into nothing, that can then safely go through your filters. I do not know how thee guys can get away with selling this stuff. I also can not understand how someone has not sued the pants off them yet for a major engine failure.

[smithy09 50]

I dunno wheels. Their website is pretty convincing.. References from Shell, tests from ICI...

[wheels 543]

I would be very careful and sceptical of anything written. It is all in how the info is "presented".

I have had a great deal of interest and work in the "Cell Disruption" field. Just ask Dr Watson. If I could have disrupted a cell using a strong magnet, trust me, it would have saved us a hell of a lot of money and time.

First off, a cell is a cell. Plant or Animal, they are both within reason, quite similar. There is nothing even remotely magnetic in a cell. In fact, if a Magnet could disrupt a cell, then don't ever allow yourself to go into a MIR scanner. The magnetic field in one of those is far more powerful or intense. Don't ever sleep on a Magnorest Wool Rest for your bed. You would wake up in the morning with dead spots all over your body

The first Testimonal they use (Bureau Veritas -) is just a paper that simply states the Unit is what the maker claims it is. A round aluminium thingy with magnets in it and it is called what the maker calls it.

So OK, lets just say it can kill Bacteria and Fungi like they say it can. Interesting point there, it should be Algae, not Fungi. So OK, they Kill it. What happens then?? So the dead and broken cells go where??

Next if you look closely, two things are done in all these tests that are very misleading. One is, water is regularly and consistantly drained off the tanks for testing. Simple really. No water, no growth. They could have the exact same result by just draining the water off with the same frequency.

I could go on, but it is much the same. There is another unit made by another maker and they claim that it aligns the molecules of the Fuel so as it actually reduces fuel consumption. Yeah right.So nice of those little molecules to stay aligned through all that pipe line and pump and injector and leap into the cylinder just the right way so as they combust just right. Which ever way that happens to be.

[Fish 0]

So I spent five years at uni studying Biotechnology and Bio-Process Engineering (also did a little time studying the mass flowrate of beer down my throat...) But I have to agree with Wheels - magnets wont kill anything.

What would work is running the bugs and associated shite through a very small nozzle, causing a very high nozzle pressure and blowing the cells apart. The only thing with that is if you could run your deisel through a very small nozel without it blocking, you could probably run your engine without any problems.......

[Farrari 4]

The general consensus is the only way to clean the tank properly is to cut hatches in the top so it can be cleaned / scrubbed by hand? This will be additional cost and shagging around but we are gettingthe impression its the only way to do the job properly? The current opens are max 2in diameter x3.

 

Don't forget that the tank should be baffled so you in all probability won't have direct access to all compartments.

[wheels 543]

Fish I wish I had of known that earlier. I will PM you though. I still have one problem I haven't been able to crack.

If you look at that Mag thing even further, they have to be run in conjunction with the engine filters, not replace them.So it doesn't work as a filter. Most of the info states that the service life of the Filters were extended a few days. Then dig further and you will note that the mag filter was dismantled and they found sludge inside. So I would say guess where the gunk that blocked the filter went to.

The destroying of the cells doesn't solve any of the real problems though. The Issue mostly tends to be with the dead cells anyway. And the debree form the cells is what causes the filters to block. What is more dangerous to any Diesel is water. A drop of water can damage the injector tips and worst case, cause the engine to stop.

[Atom Ant 0]

In all cases prevention is better than the cure, so yes even though I put up the link about the filter thingy, I wouldn't choose it. I'm just a humble ex-mechanic who hasn't worked in the field professionally for over 22 years. I'd still go for the additive which helps prevent the bug and Fish now is the time to make a small and easily removable tank which you could switch to the big tank for summer cruising - although my guess is that doing that is a messy and pain in the arse thing. Do you need such a big tank in the first place? Mind you 3 litres an hour is fair sucking it? I think I use about 1.5 an hour and I have a 65 litre tank. So we would have a similar range. Keep us posted Fish, this is a useful learning experience for us all!

[Fish 0]

We actually budget on 3 to 4 l/hr... and you think Atom Ant is heavy...

 

We are currently getting prices on a 60l plastic tank. We're expecting the price to be roughly equivalent to getting hatches cut in the stainless tank. Having three compartments it wont be a cheap job getting hatches to cover the lot Burnsco have standard red fuel tote tanks at 40l for $80 with a fuel gauge and fittings etc. I think over a certain size (60l?) baffles are required for Govt Department requirements, which pushs up cost (Wheels, don't read that bit, just breath in...)

 

120ltank gives us a range of approx 200 nm. In a busy month of racing I would manage 10-12 hrs of motoring max (return trip to Westhaven plus getting to start line etc). The current tank has 40hrs of motoring in it, so I'd be lucky to empty the tank in 4 months. If I don't go to Westhaven then would use maybe 2-4 hrs motorign a month - 10 months to empty tank.

 

A 60l tank would give us almost 100nm range. Can carry a spare 20l jerry can, but in 100nm we can refuel easily (Tuts, Fitzroy for Barrier summer cruise etc).

 

We will take the return line into the CAV filter, and we are going to put the CAV filter somewhere where we can actually see it. We've got soem good bug inhibitor additive now but I can't remember the name (the owner got it). So it will be back to basics to prevent a re-occurance, keep tank full (install smaller tank to facilitate this and ensure good turnover of fuel), use good additive, put filter somewhere we can actually see it, and adopt Wheels best practise and put the return line onto the filter, not back into the tank.

[Farrari 4]

This is a really interesting thread. A budgeted 3 to 4 litres an hour is really heavy going. What sized motor do you have?

 

As a side thought and not knowing the answer, is condensation such an issue with a plastic tank? Could you replace your current 120L stainless tank with a plastic one and then not have to keep it filled up as much?

[wheels 543]

3 to 4ltr/hr, oh if only. If i push our engine hard, we can be 20ltrs/hr, but usually work on around 8-10ltrs/hr for cruising.

[Fish 0]

The engine is a 3 cyclinder Izuzu rated at 27hp. Its not new - we can get new spare parts as forklifts have this model engine...

 

At 2,000rpm we get 6.5knts, less if its bouncy, can do 5 knts easy in most conditions. We have a shaft drive onto a Kiwi prop. We used to drag around a three blade bronze dinner plate, top motoring speed is greater with the Kiwi prop. Boat ways about 6T displacement, more with all our shite onboard but we've never weighed it. Also have a good alternator and a compressor driven fridge off it.

 

We don't have a fuel gauge but a highly calibrated stick. Consumption is always consistent with my estimates so our use is close or just over 3l/hr. This is a 25 year old kauri boat.

 

What type of consumption do others get?

[Farrari 4]

I have a 27HP Volvo Penta (2003) on a sail drive with a feathering 3 blade Kiwiprop. I haven't had the yacht long and hence don't have a good feel for worst case consumption. We have a 50L stainless tank. the 1020 ought to weigh somewhere near 4T but I have never had it weighed.

 

I can cruise at around 6 knots at 2200 RPM. At this rate it uses maybe 1.5 litres an hour from what I have experienced. We have a smallish alternator but a compressor driven fridge/freezer. I know it will suck a lot more diesel if I push it harder but all it does is bury it's bum for only a min increase in boat speed.

 

Friends of mine with the same motor in a 1020 use less than a tank of diesel (50L) for two weeks of cruising over at Barrier. I haven't tried motoring out in rough water yet to see how the consumption changes.

[John B 106]

Perkins prima 80 hp in an old 45 ft boat around 11.5 or 12 tons. Its basically a 50 hp motor with a turbo added. Getting long in the tooth now , parts can be disastrous( 2 months lost last year waiting....)

but

Bugger me if doesn't regularly eat somewhere between 2.75 and 3 l/h running at about 2500 rpm. I've measured that fuel in several times , I've checked the hourmeter, I've logged every fill or part fill and I still can budget for 3 l/h and be good to go.

[Murky 1]

It's an interesting equation with yachts.

 

Friends of mine with the same motor in a 1020 use less than a tank of diesel (50L) for two weeks of cruising over at Barrier.

I can definitely envisage this - once you have arrived somewhere like the Barrier or the BOI, it becomes a matter of just a short motor each day to a new anchorage and also to keep the fridge cold, batteries topped up and empty the holding tank.

 

I haven't tried motoring out in rough water yet to see how the consumption changes.

You will probably find that when push comes to shove, the motion of the boat encourages you to put up a sail in those sort of conditions rather than relying on the donk. You might still keep it ticking over although it depends a bit on whether anyone on board is susceptible to seasickness and their tolerance for diesel fumes.

 

I could easily envisage that peak usage for most yachts might in fact be heading off in an overloaded state on the Christmas cruise in flat calm conditiions.

[Atom Ant 0]

Christmas cruise and calm flat conditions - Do they happen at the same time?

[Murky 1]

Christmas cruise and calm flat conditions - Do they happen at the same time?

It all depends on your approach to Murphy's Law. Try thinking: overloaded boat, lots of distance to travel, can motor at 5-6 knots but sailing would be faster...you will be starting to get the picture. It all comes together even better if you have a hangover from your first night away, the sun is beating down and there is a big leftover swell.

[Atom Ant 0]

Yeah ok I get it. Kinda like when you sail out to the Barrier in a NE so it's dead maggot all the way. There's two weeks of NE and then the night before it's time to come home it changes to SW...

[Fish 0]

Hmmm, thats interesting.

Could high fuel consumption be a symptom of some other underlying issue with the engine? or could our engine just be a pig rooter?

 

We are fairly disciplined with changing the filters when we're supposed to (at least the owner is...) So the air filter should be in good nick. Its just an old, normally asperated engine, no turbo's or anything.

 

There is a sweet spot at about 1,8-1,900 revs to about 2,000. Under that there is a lot of vibration etc so we always run in the sweet spot. I might have a look see and try running the rev's a tad lower and assess fuel consumption V speed. Can't see how we could ever acheive 1.5 l/hr though.

[w44vi 17]

The rule of thumb that I was told was 1 lt per hr per 10 horses

e.g. 20hp 2lts per hr or 50hp 5lts per hr

 

just remember that a marine diesels use fuel from load not revs

[tuffyluffy 76]

Your engine does sound mighty thirsty. Im getting 2l an hour pushing 7 ton at 6.5knts with a Volvo 30hp saildrive with 2 blade folding prop. Sweet spot seems to be 2,400 rpm