Lower Micron Fuel Filter Mod - Page 5 - PeachParts Mercedes-Benz Forum

retmil46 · #61 12-01-2008, 03:47 AM

Quote:

Originally Posted by Diesel911

Another thought is that way more fuel goes through your filters than gets injected into your Engine; the rest is returned to your fuel tank. This means that after you have driven awhile all of the fuel in your fuel tank has been filtered and will be filtered again and again.

If you're using the stock filter head for the factory canister filter, that may not be entirely so.

On my '87 300D, there's an orificed bypass, 1.5 mm or so, between the inlet of the filter and the fuel return line to the tank. Anything smaller than 600 microns (the prefilter) or 1.5 mm could essentially just keep getting recirced back and forth to the fuel tank.

IE, the factory filters aren't there to clean the crud out of your fuel tank - just keep the big chunks from going thru the supply pump, and anything over 8 microns from getting to the IP and injectors.

If you want to stop the crud butt cold and clean it out of your fuel system in short order, you'll need another filter in the system that doesn't have any sort of bypass arrangement.

DeliveryValve · #62 12-01-2008, 11:18 AM

Quote:

Originally Posted by bgkast

Modification compulsion.

X2 what Bryan said.

But really for me it mainly was to have a water separator/drain in the stock filter location. The bonus of finer filtration only adds to it's obvious benefits.

DeliveryValve · #63 12-01-2008, 11:25 AM

Quote:

Originally Posted by retmil46

....
On my '87 300D, there's an orificed bypass, 1.5 mm or so, between the inlet of the filter and the fuel return line to the tank. Anything smaller than 600 microns (the prefilter) or 1.5 mm could essentially just keep getting recirced back and forth to the fuel tank.

IE, the factory filters aren't there to clean the crud out of your fuel tank - just keep the big chunks from going thru the supply pump, and anything over 8 microns from getting to the IP and injectors.

If you want to stop the crud butt cold and clean it out of your fuel system in short order, you'll need another filter in the system that doesn't have any sort of bypass arrangement.

On the 617/616 engines you can remove the banjo bolt and run a straight bolt to seal up this orifice. I run this setup so I don't have veg oil mixing with the diesel fuel. 20,000 plus miles later no noticeable issues with sealing up the hole.

Here are pics of the orifice from FI earlier in this thread.

Upper right corner is a small orifice hole.

From top down the treaded hole for the banjo bolt that can be replaced by a straight bolt to seal it up.

DeliveryValve · #64 12-01-2008, 11:33 AM

Quote:

Originally Posted by retmil46

...
..... Anything smaller than 600 microns (the prefilter) or 1.5 mm could essentially just keep getting recirced back and forth to the fuel tank.......

I just thought about this, but that orifice hole actually allows filtration again in the 616/617 engines. Don't know how the w124 setup is like. But in the w123/126 with these engines the fuel gets recirculated to through filter which ever you look at it.

retmil46 · #65 12-01-2008, 02:00 PM

On the W124, from my read on the manual, the orificed bypass is between the inlet to the filter and the fuel return line to the tank. Might be a slightly different arrangement from the orifice hole in the pics as well.

With the W124 having no hand primer and designed to be self-priming, I could think of one other reason for that orificed bypass - helping bleed off any residual air after a filter swap.

WD8CDH · #66 12-01-2008, 03:04 PM

Because of differential pressure drop, most of the fuel does go thru the filter and only a small amount goes thru the 1.5mm hole so eventually the vast majority of the particles smaller than 1.5mm but larger than 10 micron end up trapped in the filter. The primary purpose of the 1.5mm hole is to give air, because of its very low viscosity, a fast track back to the tank rather than thru the IP. The fuel system is phenominally insensitive to air.

WD8CDH · #67 12-01-2008, 03:26 PM

Quote:

Originally Posted by holtonmusicman

I've been using the following process to filter my WVO -

1) Settle for @ a week
2) "Pre-Filter" with flour sack cloth
3) Filter through 10 micron bag
4) Re-Filter using old fuel pump to pump "fuel" through a "Pure-One" oil filter. (Pure-One by Purolator has a one micron rating)

This fuel comes out BEAUTIFULLY!

My question:

Is there a reason a Pure-One OIL filter couldn't be used as a fuel filter? (using the modifications listed above to install the filter)

There wouldn't be any water separation (I am not concerned with that, been running straight WVO thinned with Kerosene (1:5) with no problems for over six months), but would have finer filtration.

Are you SURE that the Pure One is one micron? Their site states that they are 99.9% efficient based on ISO 4548-12 at 20 microns.

But, I wouldn't be as worried about filtering veggie oil as I would about water removal. Most contaminants in veggie oil are soft and cause little damage but the water left in the oil will slowly kill your IP. One week of settling may or may not be enough to get the water level low enough. It depends on temperature, convection currents and several other factors.

Diesel911 · #68 12-01-2008, 04:09 PM

Quote:

Originally Posted by WD8CDH

Are you SURE that the Pure One is one micron? Their site states that they are 99.9% efficient based on ISO 4548-12 at 20 microns.

But, I wouldn't be as worried about filtering veggie oil as I would about water removal. Most contaminants in veggie oil are soft and cause little damage but the water left in the oil will slowly kill your IP. One week of settling may or may not be enough to get the water level low enough. It depends on temperature, convection currents and several other factors.

I Emailed the Member that posted the comment on the 1 Micron Pure One filter and ask for the part # of the filter so that I could look it up. I never got a response.
I wanted to know if they made a Pure One Bypass type oil filter.

WD8CDH · #69 12-02-2008, 11:18 AM

One of my favorite sources of metric threads for making or modifying filter mounts is McMaster. Look at the various metric compression tube fittings. The bodies are usualy metric thread. 6mm tube size is usually M12 x 1.5, 8mm tube is usually M14 x 1.5 and 10mm tube is usually M16 x 1.5. Look up part number 5269K333 and then go to the catalog page for other thread options. The bulkhead fittings have the longest threads.

holtonmusicman · #70 12-08-2008, 12:01 PM

I've tried to reply via IM about the filter numbers but could not get my messages to send to you.

I do not have the part numbers on me right now but I will re-post when I get home.

I'll do some more checking as well as I don't want to post eronious information!

As far as WVO filtering and H2O problems.

I heat my oil for an hour to an hour and a half (at 300 degrees). I make sure I no longer see bubbles in the oil before I filter it.

I've also experimented with a mix of regular gasoline (3/1) and 4 oz of cetane boost for the colder months and my 240 seems to absolutely LOVE it!

I've not used regular unleaded gas before...does anyone know of any potential problems with this??

WD8CDH · #71 12-12-2008, 08:51 AM

Quote:

Originally Posted by holtonmusicman

As far as WVO filtering and H2O problems.

I heat my oil for an hour to an hour and a half (at 300 degrees). I make sure I no longer see bubbles in the oil before I filter it.

I've also experimented with a mix of regular gasoline (3/1) and 4 oz of cetane boost for the colder months and my 240 seems to absolutely LOVE it!

I've not used regular unleaded gas before...does anyone know of any potential problems with this??

I would be far more worried about long term damage to the IP from your de-watering method than any harm from the RUG.

Heating to that temperature will only remove some free water. It actually increases suspended water because water dissolves in oil at that temperature. It also concentrates corrosive contaminants like salt rather than removing them.

holtonmusicman · #72 12-15-2008, 10:19 AM

OK, now I'm a little concerned.

I've been driving my vehicle for six months using this method of filtering (only real problem I've had was plugging of pre-filter from dissolving old rubber fuel lines early on -- been replaced) and have had no problems BUT I don't want to destroy my IP (really can't afford to rebuild it)

Suggestions for eliminating H20 from the mix?

This is also the first I'd heard of the "salt" contamination. However, if the oil is filtered and the salt is still in solution is this really a concern?

DeliveryValve · #73 12-15-2008, 12:39 PM

Quote:

Originally Posted by holtonmusicman

OK, now I'm a little concerned.

I've been driving my vehicle for six months using this method of filtering (only real problem I've had was plugging of pre-filter from dissolving old rubber fuel lines early on -- been replaced) and have had no problems BUT I don't want to destroy my IP (really can't afford to rebuild it)

Suggestions for eliminating H20 from the mix?

This is also the first I'd heard of the "salt" contamination. However, if the oil is filtered and the salt is still in solution is this really a concern?

This really should be on another Thread so it will stay on topic.

But there are many opinions on how to de-water and de-contaminate the oil. But If I was using heating method, I would heat it at 150 degrees and let it cook/settle for days. I think this is the best method and if you had a window in the container, you can clearly see the separation of good oil and dirty/watered oil.

WD8CDH · #74 12-16-2008, 12:02 PM

Quote:

Originally Posted by holtonmusicman

OK, now I'm a little concerned.

I've been driving my vehicle for six months using this method of filtering (only real problem I've had was plugging of pre-filter from dissolving old rubber fuel lines early on -- been replaced) and have had no problems BUT I don't want to destroy my IP (really can't afford to rebuild it)

Suggestions for eliminating H20 from the mix?

This is also the first I'd heard of the "salt" contamination. However, if the oil is filtered and the salt is still in solution is this really a concern?

Obligatory on topic comment:

Filtering, even down to 2 microns, will not remove dissolved salts or suspended water in WVO.

A lower micron filter element, especially a water separator type is more suitable for diesel side of a two tank conversion where the diesel fuel may stay unused for a longer period of time and accumulate water from condensation.

Off topic comments:

Filtering beyond factory specs on the veggie oil side is less important both because your home pre-filtering and processing should be very good and also the contaminants in cooking oil are softer and less abrasive than contaminants in commercial diesel fuel. The filtering on the veggie side is primarily to remove incidental contamination from filling the veggie oil tank and to remove any contaminants that were already in the veggie oil tank.

The salt, even still in solution, will damage your IP.

The most effective common method of water water soluble contaminant removal is settling, but it must be UNDISTURBED settling. Even convection currents from a submerged heating element will prevent effective settling of suspended water, so most of the water settles AFTER you turn the heater off during the time that the oil slowly cools in an insulated tank.

With properly processed veggie oil, your veggie filter should last longer than the typical life of a diesel filter. I have NEVER had to replace a veggie oil filter in any of my vehicles but I have been forced to replace several diesel filters in the last few years.

-Ron
30+ years of Used Cooking Oil use and counting.

Diesel911 · #75 12-16-2008, 12:42 PM

Just a comment. When I began this thread I was only considering Diesel Fuel filtration.

Also the BF7591-D is in effect a water separator as the media is supposed to repel water.
However, I do not know if it will do so if the water is chemically combined with the fuel. my guess is not.