[MacNab]

Don't know what everyone else here is experiencing, but auto gas prices in Arizona are creeping down to around $2.50/ga while the price of avgas is staying above $4.00 or creeping up. Avgas prices usually track about a dollar above mogas, but apparently not anymore.

People seem to be flying less around here as the price goes up, so supplies *should* be up too, placing downward pressure on the price...ain't happenin'. Are the oil companies producing less? Are prices staying elevated to keep retailers in business because of lack of demand? Is that last high priced load staying in the tank at many FBO's and cheaper fuel not been delivered and factored in yet?

It is hotter than heck around here and that has an obvious affect on flying, but I was seeing a reduction of activity at the airport long before it got really hot here in Phoenix. Hoping prices drop at least a bit in the near future, at least before we get raked over the coals with higher fuel taxes...or are those nice oil company folks just trying to get us used to higher prices when higher taxes kick in?

Glad we got an RV, it gets better gas mileage than my pickup truck...

Your thoughts?

 

[rocketbob]

I have a short answer for you: run mogas! I do and I don't have any trouble with it, been doing so for several hundred hours now. The key is to find an alcohol-free source. Depending on where you're at that may or may not be a problem. I get it from farm bureau and my O-360 runs just fine on 87 octane.

$1/gal savings x 9gph x 2000 hours = $18,000. Enough to cover an overhaul and then some.

 

[vmirv8bldr]

FIFO?

I know at least one fuel supplier that works on a first in first out basis. So they charge according to what they paid for the fuel, and prices don't go down until the next truckload fills the tanks. Conversely, they don't go up until the truck replenishes the tanks either.

 

[frankh]

Yes I just switched

I have a short answer for you: run mogas! I do and I don't have any trouble with it, been doing so for several hundred hours now. The key is to find an alcohol-free source. Depending on where you're at that may or may not be a problem. I get it from farm bureau and my O-360 runs just fine on 87 octane.

$1/gal savings x 9gph x 2000 hours = $18,000. Enough to cover an overhaul and then some.

I'm running a little conservative, I.e reduced the timing to 25BTDC max (easy with Emags) and running 92 octane on 8.5:1 CR. Runs the same as AVGAS except my Max EGT numbers seem a little higher, maybe because the timing has been turned down...I.e the charge ignited later thus running hotter out the exhaust...Just a theory.

Been doing this for 20 hours up to 12,000'...have not built a vapour pressure tester yet.

My wind my Max timing back up to 34 degrees for the next test.

Out of interest, has anyone tired alcohol laden fuel yet?...I have not seen a great argument for not using it other than its a rip off...i.e less range.

Frank 7a

 

[N941WR]

Out of interest, has anyone tired alcohol laden fuel yet?...I have not seen a great argument for not using it other than its a rip off...i.e less range.

Frank 7a

Frank,

Perform a search. Turns out there are three issues with gas-a-hol. First is that some of our aircraft components (carb, injectors, etc) don't play nice with alcohol. The second is that gas-a-hol is more susceptible to vapor lock, which can happen in flight. Third, alcohol absorbs water which can separate at altitude and either freeze in your lines or just collect in the bottom of the tanks.

Your call if you want to run it. If you do, please let us know how it works out.

 

[az_gila]

It is dropping in AZ...

Don't know what everyone else here is experiencing, but auto gas prices in Arizona are creeping down to around $2.50/ga while the price of avgas is staying above $4.00 or creeping up. Avgas prices usually track about a dollar above mogas, but apparently not anymore.
.....
Is that last high priced load staying in the tank at many FBO's and cheaper fuel not been delivered and factored in yet?

The wholesale price in Tucson has been steadily going down over the last few weeks.... but we don't adjust our Airpark prices until the next load comes in. I'm sure local FBOs do the same.
We have a 10,000 gallon tank, and fuel costs more if we don't buy a full tanker load of 8,000+ gallons.

Starting at 7-17
7-24 quote was 5 cents less
7-31 quote dropped 7 cents from previous week
8-7 quote - no change
8-14 quote dropped 8 cents from previous week

A 20 cent drop in 5 weeks, and I haven't got this weeks quote yet (it's due today)... hoping for another drop since our tank is getting low...

UPDATE... It went up a penny to-day...

Gil A. - one of the 57AZ fuel managers...

PS ...our fuel is delivered from Phoenix....

 

[frankh]

Yeah so the problem is?..

Frank,

Perform a search. Turns out there are three issues with gas-a-hol. First is that some of our aircraft components (carb, injectors, etc) don't play nice with alcohol. The second is that gas-a-hol is more susceptible to vapor lock, which can happen in flight. Third, alcohol absorbs water which can separate at altitude and either freeze in your lines or just collect in the bottom of the tanks.

Your call if you want to run it. If you do, please let us know how it works out.

Yup, I have the AFP system that is compaitble with anything.

More susceptable to vapour lock..Hmm, Yes I have a system that is almost impossible to VL (two electric pumps in the wingroots)...Have not doen altitude testing on Gas-o-hol yet though..i will check when I get around to making the VP tester.

The third issue is more of a potential show stopper...I might experiment with samples of water mixed with gasohol and stick 'em in the freezer to see what happens.

Interesting.

Thanks

frank

 

[rph142]

I work for ConocoPhillips at the Wood River Refinery and i've asked several people this same question. Unfortunately, nobody gave me a clear answer. I think the basic answer is this: not all refineries make 100LL whereas all refineries make gasoline, the recent rise in gasoline prices was due to bottlenecking at the refineries..ie outages and really high demand. Of course when those gasoline making refineries came back online the price of gas went down...unfortunately the 100LL making refineries have been chugging along the whole time, therefore we have not seen an increase in production. Long story short...if youre shopping around for an engine you might want to consider one that can burn mogas. Of course i could be completely wrong.

 

[hngrflyr]

I use premium mogas in my airplane. Locally, there is more than $1.50 per gallon price difference.

 

[MacNab]

I use premium mogas in my airplane. Locally, there is more than $1.50 per gallon price difference.

No alcohol free mogas available here unless you're willing to fly to St. Johns...hmmm. That being said, we don't normally see such a large differential between the price of mogas and avgas. However, you can buy 100LL at Casa Grande for $3.50...it's a buck more at my home field. Makes one wonder what the actual wholesale price is running...

 

[RVbySDI]

alcohol absorbs water which can separate at altitude and either freeze in your lines or just collect in the bottom of the tanks.

I do not wish to hijack this thread about fuel costs but I would like to hear more discussion on the topic of water separating at altitude. If my query is better suited to a new thread I will be glad to start a new one but I wanted to ask it here after having read the above post in this thread.

It is not my intent to argue any point here. I am just interested in hearing from those chemists/engineers/theorists out there on the issue of fuel, water, alcohol and altitude.

I have questions concerning the idea of water separation in alcohol solution. What altitude/temperature are we talking about that would cause the separation of water in a solution of alcohol? How much water suspended in the solution would there have to be before this would be a problem?

There was a thread a while back that discussed a study that showed the amount of water in solution with alcohol fuel it would take before a large enough slug of it came out of solution and caused any type of problem in the flying environment we typically fly with RV's. If I remember correctly from that paper, the amount of water would have to be in the neighborhood of a pint of water in a tankful of fuel before it caused a problem. I could be wrong on this amount but whatever the amount of water was, I know in reading that article, I was a little taken aback by the amount of water in a fuel tank that it would take for the water to separate. It seemed that there would have been more pressing problems than burning alcohol as a fuel additive that would have to be addressed if that much water was in the fuel tank.

If altitude does cause water separation in alcohol blended fuel enough to be a problem, why would I have not had that problem this past July when I spent over a week driving my fuel injected V8 350 engine at over 12,000+ feet altitude in Colorado with ethanol laced 87 octane gasoline pulling a loaded trailer up and down winding mountain roads? Should I have been concerned that using the gasoline I bought that included 10% ethanol would have caused a slug of water to come out of solution?

In addition to the water issue should I have also been concerned about whether my pickup would have experienced vapor lock at this altitude? I am not aware of these issues ever causing me problems with the earthbound engine I use even at higher altitudes than I plan to fly in the RV. Why would it not be an issue in that engine but is a dire issue in the fuel injected 340 I intend to use on my RV?

I am interested in any and all comments on this topic, I suppose even if they are just anecdotal comments, but I would really love to hear from those scientists, engineers and chemists who have truly studied this issue.

 

[Daver]

mogas

Here in Albuquerque the gas stations in Bernalillo County are required to put ethanol in the gas (10% by volume; 1.5% by weight, I believe) from November to February.

Some stations pump ethanol all year long (probably less than 10%).

The 10% ethanol stuff has very high vapor pressure and some older cars (like some I've owned) have vapor lock problems.

Of course, the ethanol knocks your fuel economy off (noticeably).

IMHO the mandated ethanol program is just a federal farm subsidy.

Anyway, the places I've found without ethanol (ever) is the Indian Reservations.

Ethanol fuel in a carbureted airplane would scare me based on my experience with it in cars.

So, I buy good Indian gas for my cars & motorcycles.

Dave

 

[frankh]

This one is easy

In addition to the water issue should I have also been concerned about whether my pickup would have experienced vapor lock at this altitude? I am not aware of these issues ever causing me problems with the earthbound engine I use even at higher altitudes than I plan to fly in the RV. Why would it not be an issue in that engine but is a dire issue in the fuel injected 340 I intend to use on my RV?

.

The reason your truck did not (and will not) vapour lock is that its fuel system is designed "hydraulically correct". Namely your fuel pump is either inside or very close to the outlet of your fuel tank.

VL only occures when the suction on the fuel reduces the pressure of the fuel to below its vapour pressure. When that happens the fuel boils and the fuel pump can only pump liquid, it cannot pump vapour...Hence the name "Vapour Lock".

What reduces the vapour pressure even further is heating the fuel.

Right, so now look at the differences of a airplane system verses your truck. The fuel pump is is on the back of a nice HOT engine...Sucking (which means lower pressure) fuel from the tanks.

An engine driven fuel pump is almost vapour lock heaven!

So, in the RV you have a boost pump that is on the cool side of the firewall....it still sucks a little way from the tanks but it is a whole lot better than relying on the engine driven pump (assuming no blast tube to cool the pump here)...

On my airplane I have an electric pump in each wingroot which basically copies what you have in your truck..I.e no sucking on fuel anywhere in the system.

I did it this way specifically for mogas use and quickly realised the mechanical pump had little value in a well designed electrically dependant airplane...So I didn't fit that either.

Cheers

Frank

 

[RVbySDI]

The reason your truck did not (and will not) vapour lock is that its fuel system is designed "hydraulically correct". Namely your fuel pump is either inside or very close to the outlet of your fuel tank.

So this sounds like a "no-brainer" decision. Why continue installing non "hydraulically correct" systems in machinery where this failure can kill you?

It seems to me that even if this system is perhaps more complex or may even weigh more than the non "hydraulically correct" installation, the benefits far outweigh the downsides of complexity and weight in this situation.

Am I wrong for thinking this way?

Any others have comments on the water/alcohol solution issue?

 

[MacNab]

I think butanol based fuels are a better solution (no pun intended) than ethanol for alternate aviation fuels. There's a lot of interesting manufacturing research going on with regard to butanol production from biomass. IMHO, this is an up and coming alternate fuel source that has almost as much net energy content as avgas without some of the shortcomings of ethanol - it resists water contamination and vapor lock better than ethanol and can be transported through pipelines. Butanol also blends better than ethanol with alkylate based fuels (avgas) and is less likely to separate when blended because of contaminates (water). Plus, no engine modifications are required to run it in existing gasoline powered engines.

Net energy comparison:

Avgas - 31.0 MJ/L
Butanol - 29.2 MJ/L
Ethanol - 19.6 MJ/L

There, I hijacked my own thread. An interesting topic that could have a direct impact on our future cost of flying.

 

[frankh]

Bingo!

So this sounds like a "no-brainer" decision. Why continue installing non "hydraulically correct" systems in machinery where this failure can kill you?

It seems to me that even if this system is perhaps more complex or may even weigh more than the non "hydraulically correct" installation, the benefits far outweigh the downsides of complexity and weight in this situation.

Am I wrong for thinking this way?

Any others have comments on the water/alcohol solution issue?

Well you see there is history to contend with.

back in the days when a Lycoming first got its certification, the electrics were MUCH less reliable than they are today...Ford based alternators for example. So no one in their right mind would put their life on the line with electric fuel pumps..Even two of them.

But today in Experimental circles...well yes of course I agree I have two electric pumps..

As to complexity each pump set has an on/off switch. There is no fuel selector...To feed from the right tank you turn the right pump on and vice versa...For TO and landing you run both.

Can't get much simpler than that.... Probably weighs about a pound more than the standard Vans FI'd setup.

But remember the std system is meant for AVgas....So you can get away with being "hydraulically incorrect"..

Frank

 

[WildBill]

Frank,

Could you post a basic diagram of your fuel system. Do you use check valves anywhere?

Where are your fuel shutoff valves located? At the wing roots or further forward?

What kind/brand of electric pumps are you using?

 

[Randy Walls]

Keep an eye on Sonex

The folks at Sonex are actively researching the use of ethanol blended fuel in airplanes. I applaud their efforts and wish them well. Too bad Vans et. al. just stick their heads in the sand and ignore the problem. I doubt that 100LL will be around ten years from now, options would be nice.

 

[frankh]

Yes...IF

Frank,

Could you post a basic diagram of your fuel system. Do you use check valves anywhere?

Where are your fuel shutoff valves located? At the wing roots or further forward?

What kind/brand of electric pumps are you using?

You can tell me how to post a diagram......Oh and draw the diagram....

Anyway...its quite a simple system...The pumps come from NAPA...they are the same ones that the RWS used to use (real World solutions..the rotary folks). The tanks have to have a flop tube (or the pipe needs to exit the tank at the front of the wing to make it all fit).

The pressure relief valve comes from Airflow Performance...Its the same valve as the standard FI setup.

Now the pump simply sucks from the tank, through a cheap metal clad fuel filter from any autoparts store. Through the pump and back to the tank via the relief valve...Note I do not put it directly to the inlet of the pump for fear of air bubbles and I want cool fuel to cool the pump...not circulate the same hot fuel.

Between the pump and the valve there is a simple take off (OK I welded up a couple of steel fittings to make it all compact)...the take off goes into the cabin in the normal way.

Then there is a standard Vans non return valve (andair) and a final filter (which is really overkill I think. I wouldn't fit this again)...then the standard Vans selector valve.

Now before you all say "But you said there was no selector valve!"...the Valve is plumbed as a simple on/off valve...Which is just simply connecting up the spare port that is not normally used.

Then its forward to the flow meter and then directly to the FI servo.

Remember to wire the pumps COMPLETELY independantly, no common switches, wires or fuses...Both of mine are wired to the battery buss.
If folks are REALLY interested in using this system I will figure out how to draw it up.

I have photos as well.

Frank

Works great!

 

[frankh]

Yes but

The folks at Sonex are actively researching the use of ethanol blended fuel in airplanes. I applaud their efforts and wish them well. Too bad Vans et. al. just stick their heads in the sand and ignore the problem. I doubt that 100LL will be around ten years from now, options would be nice.

remember Vans sell sheet metal kits, their expertise is not engines/fuel systems. Like us they have their opinions I'm sure but they are just pilots like the rest of us in this regard.

Some are comfortable with unleaded fuel, some don't want to take what they perceive as a risk...I mean it makes sense, the engine cost 25k...it could be an expensive experiement if it went wrong.

Frank

 

[RVbySDI]

You can tell me how to post a diagram......Oh and draw the diagram....
. . .

If folks are REALLY interested in using this system I will figure out how to draw it up.

I have photos as well.

I would be very interested in seeing diagrams and pictures. As far as drawing the diagram surely you can draw it out and then have someone you know handy with a computer scan it in and help you post. I would be most interested in seeing your setup as I am planning to use the ECI IO-340 with ECI's new cold air induction system and return fuel lines. I would like to see how your system might function with this setup.

 

[frankh]

pictures

I have those



The open ends are connected to the tank...The spare 1/4" tube is for the return used with the AFP dump valve.

Frank

 

[frankh]

Pic of mounting bracket

The main pump bracket is made from 4130 steel.

 

[frankh]

Final filter and check valve

The filter is mounted just like the pump. I wouldn't fit the final filter again I don't think. Note the two systems join in the middle at the Tee...No selector valve



Frank

 

[frankh]

System notes

1) There is no mechanical pump used with this setup...Too complex and could be a danger of sucking air into the system.

2) Run both pumps for TO/landing

3) Must leave a reserve in each tank...Has not proven to be a problem in 200 hours.

4) I have the NAPA part number if interested...Pump costs 120 bucks...Much cheaper than the AFP pump and could be used as a substitue in a standard Van's setup.

5) AFP will happily sell you just the valve which is an aftermarket part to them.

6) To shutdown engine I turn off pumps. This drains off fuel pressure.

Frank

 

[WildBill]

diagram...use Dia

Here is a link for a free program for doing diagrams. It is quite well known among the open-source world: Dia

It is available for windows too:
http://downloads.sourceforge.net/dia-installer/dia-setup-0.96.1-7.exe
(includes the required gtk runtime environment)

further info at:
http://www.gnome.org/projects/dia/
or
http://live.gnome.org/Dia

"Dia is roughly inspired by the commercial Windows program 'Visio', though more geared towards informal diagrams for casual use. It can be used to draw many different kinds of diagrams. It currently has special objects to help draw entity relationship diagrams, UML diagrams, flowcharts, network diagrams, and many other diagrams. It is also possible to add support for new shapes by writing simple XML files, using a subset of SVG to draw the shape.

It can load and save diagrams to a custom XML format (gzipped by default, to save space), can export diagrams to a number of formats, including EPS, SVG, XFIG, WMF and PNG, and can print diagrams (including ones that span multiple pages)."

 

[RVbySDI]

thanks Frank

The pictures you show do a lot to help understand your descriptions. I plan to study your design and see how I might incorporate any of it in my installation. If you ever get that diagram drawn I would love to see it too.

 

[zav6a]

Current Draw

Frank

What sort of current draw do you see for each of the pumps?

 

[frankh]

I think

Its in the 3 to 5 amp range for each pump...I was surprised how low they were...I rigged up a little test before I installed them to check...I do know my SD8 backup alt will run pretty much all my instruments and a single pump...I get alow voltage alarm when I transmit on the radio (12.2V).

In a real IMC alternator failure I can turn off quite a bit of stuff though, including the master contactor.

Frank

 

[briand]

Anyone use these?

Frankh, Is the return line as shown in the first picture required?

 

[frankh]

Well

In the AFP system there is a #4 return but it is only used for hot starts.

In other words when doing a hot start you open the valve and it vents the hot fuel directly back to the right tank in my case.

You do this for say 30 seconds or so and now you have nice cool fuel under the hood and it starts right up.

But it is not a continuous return like there is on some automotive systems.

Frank

 

[briand]

Thanks, I think I might have asked you that before.

Could you give the napa p/n?

Is that a fuel filter inline just before the pump?

I'm thinking I might just use the single napa pump in place of the AFP using the van setup.

 

[frankh]

More

Napa fuel pump number is 2P74028

You could do that

Yes that is an inline filter but I'm not sure i would use that filter in a single filter setup as I bet they are a little cheesy and I don't know how much filter area they have.

I bet Summit Racing would have something more appropriate. I think the the NAPA pump specifies what mesh the filter should have in it if I remember correctly.

Frank

 

[briand]

Thanks. I'll check into the filter.

This is what I get from the napa website:

http://www.napaonline.com/MasterPages/NOLMaster.aspx?PageId=470&LineCode=TFP&PartNumber=2P74028&Description=Fuel+Pump+(OE+Electric+In-Line+Type)

It says 30-40 GPH.

Pressure Rating: 4-6

Just dbl. checking because there is a small price diff..

 

[frankh]

Oh yeah..

Thanks. I'll check into the filter.

This is what I get from the napa website:

http://www.napaonline.com/MasterPages/NOLMaster.aspx?PageId=470&LineCode=TFP&PartNumber=2P74028&Description=Fuel+Pump+(OE+Electric+In-Line+Type)

It says 30-40 GPH.

Pressure Rating: 4-6

Just dbl. checking because there is a small price diff..

That 4 to 6 psi is a mistake. I also called Tracy at RWS who uses them on his Rotary conversions. They are a 100psi pump and Tracy has run them this way for several years and I'm at about 200 hours running just under 30 psi.

Frank

 

[Gary Bricker]

GAry Bricker

That is a Carter Pump # P74028. If you have a parts store that handles Carter. Don't tell them it is for aircraft.

 

[briand]

I called my local Napa today to see if they had one in stock (they do). I also asked for a filter. The guy wanted to know what kind of car it was going on. I said an airplane, he said; oh you just want a 3/8 in-line filter. I don't know if he really knew what he was talking about because I know very little about aircraft fuel systems. I do know the fittings and alum. tube I have been bending is 3/8" though.

 

[frankh]

The fuel pump

has a fixed 5/16th barbed fitting on the inlet (use 5/16th fuel hose and it will easily stretch onto a piece of 8/ths fule hose.

On the discharge it has a removable 5/16th barbed fitting.

The thread is #3 ORB (O ring Boss) which happens to be 3/8th UNF.

I personally ould not rely on a barbed fitting on the discharge...Note the special fitting I welded up...

Actually I tapped out the end of the pump to 7/16ths UNF which happens to be a #4 ORB thread....Bought a #4 ORB plug and welded it to a An6 tee as you see in the pics.

The #4 fitting gives a bit thicker wall which I felt more comfortable with being as I had to wrestle it into the wing roots.

If welding up fittings is something you can't do then I would go for the Carter pump that RWS currently sells together with a pair of adaptor fittings that RWS also sell.

If this is sounding like a PITA then you might decide the standard AFP pump and filter setup that is already engineered for you is worth the extra $150 or so for a pre-engineered solution.

I.e your not saving THAT much simply by going with a different manufacturer of pump.

Cheers

Frank

 

[Aussie 9A]

What would be the consequences of having the fuel tank vent pointing into the air stream? (similar to a pitot tube) Would the positive pressure in the tank at flying speed:
(a) be too great?
(b) be sufficient to eliminate vapor lock problems?
(c) be sufficient to feed fuel to the engine in the event of fuel pump failure?

 

[briand]

"Installation Kit for RV-8/8A including Pump and Filter
Part Number = 8/8A F.I. PUMP INSTAL
Price = $555.00"

http://www.vansaircraft.com/cgi-bin...2967-78-690&browse=engines&product=fi-install


The kit for $555.00 is probably nice but since "retirement" I have much more time than money so I think I'll try to pc. something together.

$152 for a filter. Is the gas drinkable after it goes through there?

How did you regulate your system to 30 PSI?

Also noticed an Andair check-vavle in your system. Is that really needed?

Whats the big blue fitting all the way to the left in your third picture (post #24)?

Whats the brass colored 90 and the blue fitting that comes right after that in post #22?

Sorry for all the questions, I just don't know where to go with this. The only thing Vans instructions say is: "Install F-875PP FP Brkt., if you are using a low pressure boost pump (carb engine). They do not cover FI at all. Probably because they want you to buy that $555.00 kit.

I have a disassembled oxy/acetylene torch in the corner of my garage that I haven't used in about 12 years; so I could do some brazing/welding if I had to.

If I get it back together maybe I can do a couple garbage bag bombs too.

 

[frankh]

Answers

What would be the consequences of having the fuel tank vent pointing into the air stream? (similar to a pitot tube) Would the positive pressure in the tank at flying speed:
(a) be too great?
(b) be sufficient to eliminate vapor lock problems?
(c) be sufficient to feed fuel to the engine in the event of fuel pump failure?

a) No, I seen this done a lot and the difference is measured is very small.

b) Not a defined question...There no vapour lock problems with 100LL. Not an ideal system but it works....Now if you want to fly at 30,000ft there WILL be VL problems... The only reason I went the pumps in the wing roots method was because I want to run autofuel and I design these systems for a living...Not in airplanes but hydraulics don't know the difference.

c) Nope...for carburetted and DEFINATLY NOPE for fuel injected.

Now the down side...Pitot type vents are more prone to icing over due to impact ice...We heat the pitot for IFR normally but no heat for the vents.

Frank

 

[frankh]

Or a potatoe gun...

"Installation Kit for RV-8/8A including Pump and Filter
Part Number = 8/8A F.I. PUMP INSTAL
Price = $555.00"

http://www.vansaircraft.com/cgi-bin...2967-78-690&browse=engines&product=fi-install


The kit for $555.00 is probably nice but since "retirement" I have much more time than money so I think I'll try to pc. something together.

$152 for a filter. Is the gas drinkable after it goes through there?

How did you regulate your system to 30 PSI?

Also noticed an Andair check-vavle in your system. Is that really needed?

Whats the big blue fitting all the way to the left in your third picture (post #24)?

Whats the brass colored 90 and the blue fitting that comes right after that in post #22?

Sorry for all the questions, I just don't know where to go with this. The only thing Vans instructions say is: "Install F-875PP FP Brkt., if you are using a low pressure boost pump (carb engine). They do not cover FI at all. Probably because they want you to buy that $555.00 kit.

I have a disassembled oxy/acetylene torch in the corner of my garage that I haven't used in about 12 years; so I could do some brazing/welding if I had to.

If I get it back together maybe I can do a couple garbage bag bombs too.

You can get much cheaper filters than $152 bucks...I would get one with a NON-paper element....Both my filters are almost certainly paper...But I have two of them so if one plugs up I simply switch pumps. The theory is if you get water sucked up into your filter it could expand the paper and choke off the fuel supply....Has it ever happened to me?...No...Am I worried about it..NO...and do I sump my tanks?..Yes!...So your job is to weigh the risks of a single paper filter vs the cost...Mine cost $5 each and will change them everytime I happen to open the wing roots...Namely at the annual.

Regulation...Right the blue fitting (next to the gold coloured 90)is the pressure relief valve...It basically has a ball and a spring inside thats what sets the pressure...The pump simply recirculates back to its own tank...through the valve...The valve restricts the flow and sets the pressure to about 27psi.

The take off to the engine comes from upstream of this valve...Hence the regulated supply. See the welded up TEE on the discharge of the pump.

The gold fitting is simply a 90 deg fitting from the hydraulics shop...as are all the fittings that are welded...They have every thread you ca imagine. The AN threads are called JIC and are the same as aircraft AN fittings, just made of steel.

Yes the Andair check valve is needed otherwise the system will cross feed to the other tank.

The big blue theng to the left of the check valve is the final filter that I would not bother fitting if I were doing it again.

Frank