Spin on fuel filter options for cold weather

[RickTheEngineer]

Hey all, just thought I would take a chance to gain some knowledge on these spin on fuel filters. I read the posts here on the matter since months ago, and I think my M1009 is finally due for one since the leaks are getting significant. I see a lot of folks that will use a simple NAPA spin on filter, which is cheap and easy to install. Only thing is that I live up in the North East and it can get cold up here. Cold enough for me to still want my fuel heater. I know that an option is that Stanadyne FM100 fuel filter housing. I also noticed that there is a 24V top load heater option now (150 Watts), which I had not noticed previously. If I remember correctly, the fuel heater voltage is 24V right? If anyone has messed with these systems before, does anyone know if these wires will connect up to the original fuel heater control wires off the truck? Also, I am guessing that applies for the water in fuel switch as well? Finally, I noticed that the FM100 comes in a variety of port sizes. Which is the best size to use? Thanks everyone! Happy wrenching!

 

[gimpyrobb]

If you decide to go the FM100 route, the heaters from a 6.5 motor work in those housings. You can also buy them in 12 or 24v if you prefer new. The FM100 has LOTS of options.

 

[Skinny]

Be aware that the fuel heater feed from the CUCV is 12v...ask me how I know! My FM100 has a 24v heater and I just wired a simple relay that is switched by the CUCV heater wire and draws off of the 24v bus.

 

[RickTheEngineer]

Okay awesome, so the CUCV supplies 12V to the heater, so I will purchase the 12V heater. Will 150W trip something? Or can it handle that kind of load? I will just get it all new, figure I may as well just go all out on this project. Skinny, did you get a water sensor or opt for the glass bowl?

 

[Skinny]

I'm not sure what the existing CUCV circuit will handle. You could always measure the amps using a meter to see what the stock one draws. I never considered that because I used a relay with a dedicated circuit. Probably unnecessary but I didn't check the voltage compatibility beforehand which was my own fault.

I didn't get any sensor or bowl. Both my M1031 and now CUCV clone Suburban use the same dual FM100 setup with a primer bulb on one and the heater on the other. I make it a point to drain every once in a while and have never run into a problem.

I can understand if you are running a commercial truck with tons of fueling going through it or have really sketchy fuel sources but never have even come close to having any contamination issues needing a WIF light or bowl. I have drain tubes on both filter assemblies which go down past the chassis. It is short work to just do it on a regular basis to check for water contamination. I can't justify adding a bowl to check because it takes just as long to drain the filters or the added warning lamp which may fail at some point and put me in the same position of draining them regularly anyway. The logic is if I'm going to check the bowl, I may as well just grab a small cup or rag and drain them anyway.

 

[snowtrac nome]

I'm currently running my cummins turbo diesel and 72 Thiokol 2100 with no fuel heaters at 27 below 0 I have had no problems and up till yesterday I was running #2 diesel with powerservice conditioner in it. now its a #1 And #2 mix unless you are running #2 I believe a fuel heater is overrated, also letting an engine idle a bit and returning warm fuel back to the tank can make all the difference in the world. The heater on my dodge was removed when I found it was the source of an air leak I have seen this many times in the past.

 

[corelokt]

Racor with heater and water sensor. Spin on filters, water bowl, easy peasy. Even I did it right the first time.

 

[blueblaze]

I use a factory gm supplied FM100 that was used on the 6.5 diesel vans. It was cheaper to buy then ordering a fm100 from a dealer. Has the fuel heater, water in fuel sensor and not to mention the filters are easily bought at stores as you just get a normal fuel filter for a late model 6.5 diesel chevy van. Not to mention they are 5 micron filters If i remember. I elongated the holes in the mount a tiny bit, used part of an exhaust clamp that spaced the filter head away from the fire wall. Bolted right into the factory holes. I then took the connectors and converted them to the normal weather pack connectors. The wire colors were pretty well the same as they are both made by Stanadyne. My water in fuel light works and my heater works just as the factory intended. The only thing I had to do that was different is the mount is made for GM o ring style fittings. I didn't go that route. But considering it isn't high pressure it works just fine. No air leaks to date.

 

[RickTheEngineer]

Wow blueblaze, this is awesome, and I am definitely looking into this. I tried finding some specs on the wattage of the heater and whatnot. I guess what I am wondering most though is if you altered the connector to weather pack both on the filter AND on the truck? And please excuse my ignorance, but I am a little confused on what you mean for "o ring style fittings" you mean on the housing itself? I am guessing you put together the barb fittings for this application? Finally, last question I have is did you plug up the left ports? (I never saw one of these filter units in person so I am a little unfamiliar). Also, what was the priming procedure?

 

[gimpyrobb]

The FM100 can use NPT pipe thread for fuel connections which is tapered or the O-ring seal style which isn't a tapered thread. Converting to and from shouldn't be a big deal.

 

[blueblaze]

I had to alter one connection on the truck as the one connection looks like this. And the connectors on the filter mount itself were a flat style pin whilst the the 2nd truck connection is the normal pin style connector. There is only two fittings going in and out. The other ports were never casted into the unit from factory. As you were concerned with fuel gelling, so was I. I live in Northern ontario, where minus 22f - 40f is not out of the question. Never had an issue with gelled fuel ever. The fittings I got from the local NAPA, technicially your not supposed to use them with this mount as it'll let it leak but i've never had an issue. GM started in the early ninties I believe with their own style fitting. It looks like the one shown. But I couldn't find any fittings with that style to use on the filter head besides those fuel line repair kits that dorman sells in the help section. I can't remember sizes now, but I just used a fitting that threaded into the housing and used thread sealer. The port inside the filter head isn't tapered like the fitting, its flat to accept the O-ring fitting but I've never had any problems. As for the heater wattage, I'm not sure. Probably is the same as the normal FM100 which is 100watt. Comes on around 42f and shuts off around 75f.

 

[blueblaze]

oh and priming procedure is identical to the factory Model 80. In the first pictures you can see a petcock in the filter head right above the white arrow on the filter collar. When you change filters, just fill it up with diesel, put a hose on the petcock and drain the air out, while you crank it. To be honest, I've never had to prime it ever. I've just filled the new filter with fuel and started it up. Runs rough for about 10 secs and its done. Can't do that with the box style though. There is also a drain on the bottom of the filter as well.

 

[rodent]

Just wanted to update on fitting size. They are 16mm with o-ring. My speed shop had some in stock that goes to -6AN. After that I did 90 degree -6AN to barb and also added a -6AN with 1/8 NPT gauge adapter.

 

[blueblaze]

I wish I would've had access to those fittings. You are correct on the line connection. It is an M16 O-ring style. I contemplated changing over to the proper fitting but have had zero issues with the current setup. I did return your message and I believe you may have your connections backwards. Cheers.