TheSamba.com :: View topic

Tue Feb 09, 2010 12:17 pm

Didn't see a separate thread on this, figured I'd start one working off KCrow's recent thread on his bus fire.

Not knowing the first thing about the details of fuel flow, etc. hoping to get some direction from you all on how to install a solenoid fuel shut off valve between the tank and the engine bay.

First off what product to use, what specs to look for?

I found this site that seems to have plenty and affordable:
https://www.altfuel.com/solenoids.htm

[edit]
***NOTE***
These valves will not work gravity fed, confirmed by the dealer:

"Unfortunately, our valves do require pressure on the seat to seal. When the valves are de-energized the fuel is on the backside of the seat pushing it down on the orifice. The higher the pressure, the tighter the seal. The valves must have a minimum of 1/4 p.s.i. to seal. Gravity flow is not enough."
[/edit]

Paired with two NPT fuel line hose barb fittings any of those should be good to go it seems.

Assuming those would work physically, hoping you guys who know about such things can advise what specs to look for in the valve itself:

Max pressure?
Temp. range?
Flow rating?
Do I need the 1/4" orifice, or would the 1/8" Century one be ok?

Would that Century inline one be too whimpy, or a concern because the solenoid surrounds the line?

Tue Feb 09, 2010 1:12 pm

It seems to me that the thing to do would be to contact the vendor, email them a photo of the under-tank area and the size of the fuel line, and ask them what they recommend in terms of the solenoid and mounting so it is secure.
It would be nice if it could be mounted rigidly to the bottom of the tank, and then go to flex line so a filter could be installed, before connecting to rigid line on the engine. Ideally they would provide fittings as well.

Those are good prices. I would be down for one after we know all that is needed.

Thanks for the legwork!

Tue Feb 09, 2010 1:16 pm

Considering you just saved me trying to make a drag link puller out of hardware parts, I'd say we are more than even on the exchange! 8)

My concerns foremost are the specs on the pressures, flow and inner diameter of the valve.

What does a 1600 dp draw in terms of fuel flow?
I have to assume pressure is not an issue unless these things are EXPECTING pressure to work right.
What's the diameter we are looking for on standard fuel line?

Those are the things I don't know, and contacting the supplier, they'd probably ask.

My instinct is that whatever a 1600dp will need, these things will more than provide, considering they are made for modern engines. Just want to be sure, considering its the fuel line we're messing with.

The other concern would be electrical draw, current, amps.

Tue Feb 09, 2010 1:25 pm

As far as install, I've not gone too far on that yet, waiting to figure which is the best of the products before I figure out how to install it.

But...

I figured first and foremost it would be outside the engine bay. The idea is to stop flow in a fire situation, and a fire could damage the valve open if its mounted in the engine bay.

Next, it would need to have the water proof electrical connectors. That's just smart.

Third, 1/4" NPT fittings with compression fitting on the other end, that's probably the way to go as then it could be in-line mounted right to the metal fuel tubing instead of in-line on the metal tubing but with flex tubing to make the connections. The compression fitting would also help stabilize it however its mounted.

Finally, without looking at it directly, rather by memory, seems like you could use a little bracket to hold the solenoid, and screw the bracket to the wall of the engine bay, behind the fan shroud, right where the fuel line goes into the bay. But if compression fittings are possible, might not even need to screw it anything; a zip tie might be all that's needed.

Tue Feb 09, 2010 1:47 pm

I have a question. Does it work better with fuel pressure
pushing through it or fuel pump pulling fuel through it.

I have a fuel injected block in my bus and use a rotory
pump mounted on the frame horn next to the transaxle.

Tue Feb 09, 2010 2:58 pm

polo wrote: Considering you just saved me trying to make a drag link puller out of hardware parts, I'd say we are more than even on the exchange! 8)

My concerns foremost are the specs on the pressures, flow and inner diameter of the valve.

What does a 1600 dp draw in terms of fuel flow?
I have to assume pressure is not an issue unless these things are EXPECTING pressure to work right.What's the diameter we are looking for on standard fuel line?

Those are the things I don't know, and contacting the supplier, they'd probably ask.

My instinct is that whatever a 1600dp will need, these things will more than provide, considering they are made for modern engines. Just want to be sure, considering its the fuel line we're messing with.

The other concern would be electrical draw, current, amps.

the valve to avoid is a pilot operated valve meaning that a pilot opperated valve requires pressure to opperate and we are trying to cut the fuel off at the tank. Also of importance is the valve needs to be "power open" or "normally closed" as when you turn the key off that valve loses power and slams shut. I personaly would avoid compression anything as compression fittings belong under a sink in your home they are no place being used with fuel. I just don't trust them. I have seen compression nuts lossen or crack as well as the ferrel itself split in two. Ill stick with good ol' stainless hose clamps on brass barb mechanical fittings on fuel line that will get replaced yearly. just my .02

Tue Feb 09, 2010 3:08 pm

My plans for my bus are...
AN-6 fitting from the tank
AN-6 90 degree fitting to a manual shut off valve
AN-6 braided hose to billet fuel filter
An-6 fitting from filter to electric shut off valve
AN-6 hose from valve to bulkhead fitting through firewall
AN-6 line from bulkhead to electric fuel pump & regulator.

Electric shut off valve located AFTER fuel filter to prevent it from getting gunked up. Manual valve right off the tank is left open, but enables manual shut off for maintenance (cleaning filter) or for by-pass of electrical valve if it fails. I route the fuel line through the body (yes I had to drill a hole) so I can disconnect the fuel supply from one easy to reach spot in the engine compartment (at the fuel pump/regulator) when dropping the motor.

I am searching for an affordable solenoid activated switch that opens when energized and doesn't require fuel pressure in front of the valve to open. This valve may be it.

Tue Feb 09, 2010 3:22 pm

I have never bought AN-6 fittings but heard they are costly. How much for all that?
I like hardline plumbing but would be concerned about metal fatigue unless the valve was independently supported. Would not want to screw into the shelf beneath the tank, but a quick rosette weld of a bracket would fit with my approach of "do no harm".

I think flare fittings would work well for something like this.

As I read it,t the internal bore is 1/4" full port. That is more than adequate for anything other than full-on racing engines.

Tue Feb 09, 2010 4:09 pm

Well, looking into it, the solenoid valves in that link are Imperial sizes, and the stock hard fuel line is metric, so compression fitting wouldn't work unless you use a metric solenoid valve (or imperial tubing.) To be pure, I suppose one should use a metric valve.

For hard valve, I was planning on using this:
http://www.wolfsburgwest.com/cart/DetailsList.cfm?ID=211209021E

From there am thinking the simplest is cloth covered rubber connection to the solenoid valve fitted with hose bib inserts, from there another soft connection to hard pipe that takes it to the fuel pump on the other side of the firewall.

If I can find a reasonably priced solenoid pump with metric compression fittings, that'd be my ideal, leaving all hard pipe until you get to the fuel pump.

Tue Feb 09, 2010 4:16 pm

Major Woody wrote: Would not want to screw into the shelf beneath the tank, but a quick rosette weld of a bracket would fit with my approach of "do no harm". There's the little tabs under the tank shelf that are there to hold the fuel line, probably could use those somehow to hold the valve...

Tue Feb 09, 2010 4:36 pm

sventinker wrote: the valve to avoid is a pilot operated valve Well, the ones in my link state "Two stage - pilot operated for opening assurance at high pressures" :(

Tue Feb 09, 2010 4:54 pm

I'm wondering if it wouldn't be simplest to just take that WW reserve valve, crimp the top intake and set up a fuel reserve cable system as the emergency shut off...

Tue Feb 09, 2010 5:47 pm

I have a 66.
I have read that the earlier buses are gravity fed to the fuel pump.
My question is....does my 66 gravity feed?
So if I take off the fuel line to the pump it will run with gasoline pressure from the bottom of the tank?
New bee questions..appologize in advance... :oops:

Tue Feb 09, 2010 5:49 pm

mick av-8 wrote: I have a 66.
I have read that the earlier buses are gravity fed to the fuel pump.
My question is....does my 66 gravity feed?
So if I take off the fuel line to the pump it will run with gasoline pressure from the bottom of the tank?
New bee questions..appologize in advance... :oops: Yup.

Tue Feb 09, 2010 11:21 pm

I suppose one could use a solenoid or servo to operate a manual valve, such as the WW one above.
Or maybe using an electric pump outside the engine compartment - I'm assuming that fuel wouldn't flow freely out of a pump that is off.

Tue Feb 09, 2010 11:58 pm

How about this one? http://cgi.ebay.com/3-8-Electric-Solenoid-Valve-12...439d151bd9

Wed Feb 10, 2010 7:50 am

Teeroy wrote: How about this one? http://cgi.ebay.com/3-8-Electric-Solenoid-Valve-12...439d151bd9 Nope. That one specifically says "not suitable for gravity feeds" in the description.

This may be more difficult than we thought...

Wed Feb 10, 2010 7:54 am

I've got an email into the guys at the original link I posted to inquire if they have any valves for a gravity feed application.

There was also this one that malachai posted in KCrow's thread:
http://www.autoelectricsupplies.co.uk/product/731

I've got an email in to them as well.

Wed Feb 10, 2010 10:48 am

Email response from AFS:

Quote: Michael,

Unfortunately, our valves do require pressure on the seat to seal. When the valves are de-energized the fuel is on the backside of the seat pushing it down on the orifice. The higher the pressure, the tighter the seal. The valves must have a minimum of 1/4 p.s.i. to seal. Gravity flow is not enough.

Strike their products off the list, I'm editing my original post to reflect this.

Wed Feb 10, 2010 10:54 am

Did get a confirmation from Auto Electric Supplies that their's "should" work gravity fed:

"Hello,

Can you tell me, will this valve work for a gravity fed fuel (petrol)
line?

http://www.autoelectricsupplies.co.uk/product/731

===

Should be fine

Best regards

Matt"

I'm not satisfied with "should" (looking for "will" or "has") and have pressed back for any testing done on it as gravity fed, how is the valve closed? etc.