Fuel Filtering System

Thanks people for the ideas and info... My engines are tiny (twin 21hp saildrives) and the 'daytanks' are actually good for 16 hour at cruise, for each engine I have learnt a lot... Much appreciated...

Build is nearing completion 39ft x 21ft

 

Nearly impossible to filter fuel as its pumped in. You would need huge flow capacty filters. And then you would have to strore this stinky, monster fuel filter rig onboard.

I find cold beer to be the best filter. The brand doesnt seem to matter so I normally go local. When the mini tanker rumbles down to the waterfront ,its tanks gets all shaken up and the bog becomes suspended. I break out a cold six pack and a few sandwiches...feed its driver, tell a few sea stories, crack jokes and let the suspended mini tanker bog settle to the bottom. Works reasonably well. A short section of clear tubing in the feed pipe also acts as a good bog indicator...sense bog...breakout another six pack

 

ON "18" wheel trucks the fuel is returned to tanks outside in the breeze.

They find the entrained air in the fuel to be a bigger problem than heat.

The injection is an unknown when each injector has a different mix of fuel/ air being injected.

Their solution is an aftermarket unit that gets rid of the air.

Don't know if boats that seldom operate at full power would get any mpg advantage.

But it does seem to be a problem for the 350- 600hp engines.

FF

 

Yes, the West filters are slow but not that slow!

 

This may be of interest to some as to what we have been doing for over 15 years in all types of applications up to 750 HP in both recreation and for the guys that burn upwards 15,000 gallons of fuel per engine per year.

As time went on, we stayed up with the most modern advances in fuel filtering media developed by Fleetguard...Our focus has always been a simple change out with a minimum of mess and having a very large capacity for the application to keep maintenance down, besides offering multiple layers of filtration that sends "ready to burn fuel" to the engines "last chance filter so you do not have to rely on it.......Not for all, but certainly for those who do their research and want to avoid any potential issues.. For those with electronic engines having common rail fuel systems, Multi-Stage Fueltration is a must for to protect your investment......

http://sbmar.com/Articles/MarineFuel-Filtration_Introduction.php

(Multi-Stage Fueltration™Systems)


Cheers, Tony

http://www.sbmar.com

 

Tony,

Just been reading your many interesting articles on your web site.

Could you tell me please, with the new style high pressure common rail fuel injected modern diesels, is it now possible to run the engine for its entire life as a cruising long distance motor, at only 25% of its rated hp, running not much above idle really, without causing grief to the cylinder walls from glazing etc.

It was always the case that diesels run 75% of the time at 75% throttle for longevity (referring to high speed diesels here), can they now be run a very low throttle settings because they are computer controlled injectors?

 

Landlubber,

I put this together about 10 year ago... IMO, nothing has changed other than with the advant of ultra modern design and machining practices used in todays latest electronic engines, mixed in with ECM controlled fuel management for every RPM and load possible, low speed running is even less of an issue..

http://sbmar.com/main/articles/low_speed_running_break-in_of_marine_diesels/


Cruise away at the vessel speed and engine rpm or load that are most comfortable and fit your wallet as to overall efficiency of going from one place to another.. If the circumstances are right, run 'er up to a high criuse for a few minutes to warm up the combustion and clean things up.. Other than that, IMO, just an old wives tale that is no longer applicable..


Tony

 

Thanks Tony, yeah i read that article, but seeing as it was pre common rail high pressure systems, just thought that you may have other ideas.

The control of the fuel now must make them very fuel efficient and economical, just a pity that a set of new injectors are dearer than the whole engine to start with!

 

Tony,

Thanks for the links to your very informative website. It will be a great help in designing not only my fuel system but other systems as well.

Best Regards,

SeaJay

 

Yah Tony, My observation is similar. Im running a naturally aspirated MTU . Ive operated as you state since the motor was new. At 13,000 hrs the engine shows surprisingly little wear. last Compression test was good on all cylinders. Lube oil burn rate is consistent since new. I cruise at 1400 rpm. Of course this is a low power output per cylinder volume engine.

 

Michael, what model and what RPM and HP rating?

 

Its an MTU 6R 183 AA 61 rated at 159kw. Im ordering parts for it at this minute. Also sold as a Mercedes product . Massive lump of steel with a 40 litre oil sump.

 

The mechanism for the dual Racor filters (manifolded with a 3-way ball valve between them) is air-tight. Its operation is simply to direct flow from the incoming fuel line to one or the other filter. If the valve is rotated it simply changes the ports on the valve's mechanism to direct the fuel flow to the other filter. It does this simultaneously with the "in" and "out" ports of the filter assembly by using a common internal shaft. The valve has 4 positions, each 90 degrees apart on the valve rotation. The porting is "All Off" which obviously mechanically isolates the in and out ports at the valve block (no part of the filter assembly is open to either port), then one position for each of the filters, directing flow into and out of one or the other, and the last position is "All On" which opens both filters' "In" and "Out" ports to the fuel in and out, essentially paralleling them.
The Algae-X system is widely regarded as smoke-and-mirrors by many knowledgeable marine diesel professionals. If you take one apart (an Algae-X, not a knowledgeable marine diesel professional) you'll find a magnet. That's it. A circular magnet, around the perimeter of which the fuel passes once. Fuel In, magnet, fuel out. You probably know about as much as the rest of us about magnetized fuel, right?

 

Scott,
You have clarified something for me about these dual filter setups…as the single valve is turned; the 4 individual ports operate simultaneously so that fuel flow is not interrupted. Can I further assume that both filters are primed at all times? If this is the case, is it necessary or advisable to periodically run fresh fuel through the standby filter?

All,

On Tony’s excellent site, he mentions a couple of times about the messiness of changing out the Racor filters as opposed to the spin-on filters. After everything I’ve read so far, I'm confident that all of these filters will do a good job if the system is configured properly. So now I’m interested in the lifetime costs of the various filters and the ease of use/servicing. Thoughts?

Tony also mentions (as do others) that the fuel should be taken from the bottom of the tank so as to get all of the crud and water out as soon as possible. The dip tube in my tanks goes down to about 2” above the bottom of the tank. I’ve also got this 1-1/2” FPT insert on the side of the tank also close to the bottom. I suspect I could rig something up so that I could pull from the very bottom of the tank. Any reason to think this would be worth the effort?

I’m still looking for ideas for using this insert. At this point I’m just thinking about installing a 1-1/2” ball valve on it, "just in case", but am wondering if there isn’t a more specific function I could be planning for. I would prefer to install whatever I need at this time rather than crawling back in there at a later date.

 

Using the port to balance the tanks would be an idea.
In a lifetime? Racors vs. spin-ons could be argued either way. Racors are cheaper because they have cheaper elements. Spin-ons are cheaper because you don't have the initial purchase price. If you don't have a common rail engine, use the filter you have. If you are using a Racor with a common-rail engine, you are also trusting that the paint flecks, dander, dust, and anything you missed when changing the Racor filter (and anything you missed when putting the filter back together because, face it, you're not going to leave that goober in the bottom of the sitebowl). The single biggest thing you can do to save money is install a vacuum gauge after the filters and stop changing them so much before they need changing.
That Tony is a pretty smart guy, huh?