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| Electric fuel pump safety switch plumbing [message #239076] |
Fri, 07 February 2014 11:26  |
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SeanKidd
Messages: 747
Registered: June 2012
Location: Northern Neck Virginia
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C'mon spring!
I'm installing dual Carter P4070 electric fuel pumps. I will also be replacing my oil pressure sender when I install my safety switch. For those who have BTDT...
What is best practice for installing the 1/8 NPT nipple, tee, sender and switch?
I am leaning toward a 1/8 NPT stainless steel hex nipple, but can only find one in 2 1/2 inches...I've read 3" is needed....is everyone in agreement that brass or bronze is two soft for the additional weight? Do I need to 45 the sender like in some Olds applications, and lastly, do I need a method of bleeding air out (my initial thought is, will the oil stay there? ( finger on the straw trick)) all comments are welcome.
Sean and Stephanie
73 Ex-CanyonLands 26' #317 "Oliver"
Hubler 1-Ton, Quad-Bags, Rear Disc, Reaction Arms, P.Huber TBs, 3.70:1 LSD Honda 6500 inverter gen.
Colonial Travelers
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| Re: Electric fuel pump safety switch plumbing [message #239079 is a reply to message #239076] |
Fri, 07 February 2014 11:45  |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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| SeanKidd wrote on Fri, 07 February 2014 10:26 |
C'mon spring!
I'm installing dual Carter P4070 electric fuel pumps. I will also be replacing my oil pressure sender when I install my safety switch. For those who have BTDT...
What is best practice for installing the 1/8 NPT nipple, tee, sender and switch?
I am leaning toward a 1/8 NPT stainless steel hex nipple, but can only find one in 2 1/2 inches...I've read 3" is needed....is everyone in agreement that brass or bronze is two soft for the additional weight? Do I need to 45 the sender like in some Olds applications, and lastly, do I need a method of bleeding air out (my initial thought is, will the oil stay there? ( finger on the straw trick)) all comments are welcome.
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Sean--I can't remember the exact combination of fittings I used, but there is no need to bleed anything.
Bob de Kruyff
78 Eleganza
Chandler, AZ
[Updated on: Fri, 07 February 2014 12:34] Report message to a moderator |
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| Re: [GMCnet] Electric fuel pump safety switch plumbing [message #239081 is a reply to message #239079] |
Fri, 07 February 2014 11:59 |
James Hupy
Messages: 6806
Registered: May 2010
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Sean, not sure that stainless steel pipe nipples are an improvement over
brass or bronze. Ordinary steel is what I would prefer in this situation.
Just has to be long enough to allow you to get a wrench on the bottom of
the sender easily. Lots of different senders have been used here. For the
fuel pump safety switch, some form of jumper is needed to make the pumps
run for priming before cranking the engine. Otherwise they will not run
until oil pressure is present in the system. One more thing to think about,
I guess.
Jim Hupy
Salem, Or
78 GMC Royale 403
On Feb 7, 2014 9:45 AM, "Bob de Kruyff" <NEXT2POOL@aol.com> wrote:
>
>
> SeanKidd wrote on Fri, 07 February 2014 10:26
> > C'mon spring!
> > I'm installing dual Carter P4070 electric fuel pumps. I will also be
> replacing my oil pressure sender when I install my safety switch. For those
> who have BTDT...
> >
> > What is best practice for installing the 1/8 NPT nipple, tee, sender and
> switch?
> >
> > I am leaning toward a 1/8 NPT stainless steel hex nipple, but can only
> find one in 2 1/2 inches...I've read 3" is needed....is everyone in
> agreement that brass or bronze is two soft for the additional weight? Do I
> need to 45 the sender like in some Olds applications, and lastly, do I need
> a method of bleeding air out (my initial thought is, will the oil stay
> there? ( finger on the straw trick)) all comments are welcome.
>
> Sean--I can't remember the eact combination of fittings I used, but there
> is no need to bleed anything.
> --
> Bob de Kruyff
> 78 Eleganza
> Chandler, AZ
> _______________________________________________
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| Re: [GMCnet] Electric fuel pump safety switch plumbing [message #239084 is a reply to message #239081] |
Fri, 07 February 2014 12:34 |
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SeanKidd
Messages: 747
Registered: June 2012
Location: Northern Neck Virginia
Karma: 4
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thanks Jim, I plan on using the original aux/main switch to control a relay for the pumps...the selector valve, despite being reliable (and most likely ) 40 years old is coming out. A momentary prime button adjacent to the ignition switch is in the scope. Despite resealing my Q-jet, it still leaks down, any opportunity to prevent cold cranking is a good one.
Sean and Stephanie
73 Ex-CanyonLands 26' #317 "Oliver"
Hubler 1-Ton, Quad-Bags, Rear Disc, Reaction Arms, P.Huber TBs, 3.70:1 LSD Honda 6500 inverter gen.
Colonial Travelers
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| Re: [GMCnet] Electric fuel pump safety switch plumbing [message #239085 is a reply to message #239084] |
Fri, 07 February 2014 12:37 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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| SeanKidd wrote on Fri, 07 February 2014 11:34 |
thanks Jim, I plan on using the original aux/main switch to control a relay for the pumps...the selector valve, despite being reliable (and most likely ) 40 years old is coming out. A momentary prime button adjacent to the ignition switch is in the scope. Despite resealing my Q-jet, it still leaks down, any opportunity to prevent cold cranking is a good one.
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Sean, another thing I did while I was at it, was to add an idiot light switch that connects to a buzzer. That way if I have a pressure loss, I'll know right away rather than just counting on me to be looking at the gage. The engine will run for a long time even after a pump stops due to low pressure.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: [GMCnet] Electric fuel pump safety switch plumbing [message #239086 is a reply to message #239085] |
Fri, 07 February 2014 12:47 |
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SeanKidd
Messages: 747
Registered: June 2012
Location: Northern Neck Virginia
Karma: 4
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Senior Member |
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[/quote]
Sean, another thing I did while I was at it, was to add an idiot light switch that connects to a buzzer. That way if I have a pressure loss, I'll know right away rather than just counting on me to be looking at the gage. The engine will run for a long time even after a pump stops due to low pressure.[/quote]
Ah.....good idea, I know what it's like to run out of oil...  10 miles into maiden voyage(trip home after purchase) oil cooler line catastrophically failed, didn't make it to the eleventh mile.
Sean and Stephanie
73 Ex-CanyonLands 26' #317 "Oliver"
Hubler 1-Ton, Quad-Bags, Rear Disc, Reaction Arms, P.Huber TBs, 3.70:1 LSD Honda 6500 inverter gen.
Colonial Travelers
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| Re: [GMCnet] Electric fuel pump safety switch plumbing [message #239090 is a reply to message #239079] |
Fri, 07 February 2014 13:01 |
Gary Worobec
Messages: 867
Registered: May 2005
Karma: -1
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I used the brass nipple but then ran a piece of -3 Aeroquip SS hose to the
underside of the floor and remote mounted the sender and low oil pressure
switch. No need to bleed anything.
Thanks,
Gary and Joanne Worobec
1973 GMC Glacier
Anza, CA
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Bob de Kruyff
Sent: Friday, February 07, 2014 9:45 AM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] Electric fuel pump safety switch plumbing
SeanKidd wrote on Fri, 07 February 2014 10:26
> C'mon spring!
> I'm installing dual Carter P4070 electric fuel pumps. I will also be
replacing my oil pressure sender when I install my safety switch. For those
who have BTDT...
>
> What is best practice for installing the 1/8 NPT nipple, tee, sender and
switch?
>
> I am leaning toward a 1/8 NPT stainless steel hex nipple, but can only
find one in 2 1/2 inches...I've read 3" is needed....is everyone in
agreement that brass or bronze is two soft for the additional weight? Do I
need to 45 the sender like in some Olds applications, and lastly, do I need
a method of bleeding air out (my initial thought is, will the oil stay
there? ( finger on the straw trick)) all comments are welcome.
Sean--I can't remember the eact combination of fittings I used, but there is
no need to bleed anything.
--
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: [GMCnet] Electric fuel pump safety switch plumbing [message #239101 is a reply to message #239093] |
Fri, 07 February 2014 15:30 |
Mr ERFisher
Messages: 7117
Registered: August 2005
Karma: 2
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Senior Member |
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here it is from Carter themselves
http://www.gmcmhphotos.com/photos/misc/p19123-electric-fuel-pump-wiring.html
and the why
http://gmcmotorhome.info/engine.html#pump
gene
gene
On Fri, Feb 7, 2014 at 12:53 PM, Jon Payne <embrep@sbcglobal.net> wrote:
>
>
> [quote title=James Hupy wrote on Fri, 07 February 2014 12:59]
> "For the
> fuel pump safety switch, some form of jumper is needed to make the pumps
> run for priming before cranking the engine. Otherwise they will not run
> until oil pressure is present in the system".
>
> As I understand, the safety switch is also wired to the starter so when
> the key turned to start, power is applied through the NC which is connected
> to the pump. Then when sufficient oil pressure is present the switch is
> moved to the NO which connects to the IGN terminal on the ignition switch.
>
> Jon
>
> http://www.gmcmhphotos.com/photos/data/5607/OilPresSchem.jpg
>
>
> --
> Jon Payne
> 76 Palm Beach
> Westfield,IN
> _______________________________________________
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--
Gene Fisher -- 74-23,77PB/ore/ca
"Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
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| Re: Electric fuel pump safety switch plumbing [message #239105 is a reply to message #239076] |
Fri, 07 February 2014 15:48 |
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=SeanKidd wrote on Fri, 07 February 2014 09:26]C'mon spring!
I'm installing dual Carter P4070 electric fuel pumps. I will also be replacing my oil pressure sender when I install my safety switch. For those who have BTDT...
What is best practice for installing the 1/8 NPT nipple, tee, sender and switch?
I am leaning toward a 1/8 NPT stainless steel hex nipple, but can only find one in 2 1/2 inches...I've read 3" is needed....is everyone in agreement that brass or bronze is two soft for the additional weight?
Sean, McMaster-Carr has all kinds of pipe; I used regular iron/steel to make the fitting, as I previously had brass/bronze crack.
geo groth '73 260 Sequoia
Carson City Nevada 89703
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| Re: [GMCnet] Electric fuel pump safety switch plumbing [message #239106 is a reply to message #239076] |
Fri, 07 February 2014 15:49 |
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USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
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Sean,
I used stainless steel pipe fittings from McMaster Carr.
Click on this link: http://www.mcmaster.com/#stainless-steel-pipe-fittings/=qlesyb
A page will open that has all the different type of fittings you'll need.
In the column to the left you will see Material click on Stainless Steel.
The column will change and under Pipe Size click on 1/8
The column will change again and under Connection click on National Pipe Taper (NPT) Thread
You've now bored down to all the Stainless Steel 1/8" NPT fittings McMaster Carr has.
Click on Pipe Nipples and Pipe and a new window will open.
Click on Threaded on Both Ends
Scroll down to Thick-Wall Stainless Steel Threaded Pipe Nipples and Pipe
There you will find thick wall SS nipples starting at 1 1/2" up to 4" by 1/2" increments.
Those are the nipples I used, unfortunately I'm at home and don't have access to the ones I bought for The Blue Streak which are at
my workshop. I stacked two "T's" on top of each other as I have a Digi Panel that requires a separate pressure sender and a remote
gage so I needed three ports:
1) OEM sender
2) Digi Panel sender
3) Remote gage sender
Regards,
Rob M.
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
-----Original Message-----
From: Sean Kidd
C'mon spring!
I'm installing dual Carter P4070 electric fuel pumps. I will also be replacing my oil pressure sender when I install my safety
switch. For those who have BTDT...
What is best practice for installing the 1/8 NPT nipple, tee, sender and switch?
I am leaning toward a 1/8 NPT stainless steel hex nipple, but can only find one in 2 1/2 inches...I've read 3" is needed....is
everyone in agreement that brass or bronze is two soft for the additional weight? Do I need to 45 the sender like in some Olds
applications, and lastly, do I need a method of bleeding air out (my initial thought is, will the oil stay there? ( finger on the
straw trick)) all comments are welcome.
--
Sean
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Unsubscribe or Change List Options:
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Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
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| Re: [GMCnet] Electric fuel pump safety switch plumbing [message #239114 is a reply to message #239084] |
Fri, 07 February 2014 16:25 |
mikethebike
Messages: 331
Registered: January 2014
Karma: 0
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| SeanKidd wrote on Fri, 07 February 2014 12:34 |
thanks Jim, I plan on using the original aux/main switch to control a relay for the pumps...the selector valve, despite being reliable (and most likely ) 40 years old is coming out. A momentary prime button adjacent to the ignition switch is in the scope. Despite resealing my Q-jet, it still leaks down, any opportunity to prevent cold cranking is a good one.
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If your carb is leaking down it is probably a blocked air passage causing the fuel to siphon out through the booster venturi.....at least that what caused Holleys to leak down when there was no evidence of gasket failure.
Start the engine for a moment then shut it down, remove the A/C top, release the choke and shine a light down into the primaries and observe for a few minutes. If your throttle plates are wet and remain so or you SEE fuel dripping from the booster venturis you have isolated your leak.
If this is indeed your problem the secondary problem will be shortened ring life due to the fuel washing the cylinder walls.
[Updated on: Fri, 07 February 2014 16:32] Report message to a moderator |
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| Re: [GMCnet] Electric fuel pump safety switch plumbing [message #239116 is a reply to message #239093] |
Fri, 07 February 2014 16:38 |
gbarrow2
Messages: 765
Registered: February 2004
Location: Lake Almanor, Ca./ Red Bl...
Karma: 3
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If one chooses to run both the mechanical and electric pump and is not concerned with a "priming" function is there any reason not to power the pump directly from the alternator output or from the center post of the battery isolator(same thing)?
Much simpler and cheaper than wiring in a LOP cutoff switch. Same result- engine dies- no alt output-no power to the pump.
Is the constant 13-14 volts detrimental to the pump?
AND
What is desirable about a priming circuit to achieve instant starting of a cold engine? What happened to the concept of cranking the engine to build oil pressure before firing it off?
Just curious
Gene Barrow
Lake Almanor, Ca.
1976 Palm Beach
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| Re: [GMCnet] Electric fuel pump safety switch plumbing [message #239117 is a reply to message #239114] |
Fri, 07 February 2014 16:39 |
Bruce Hart
Messages: 1501
Registered: October 2011
Location: La Grange, Wyoming
Karma: 5
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Here are plugs for the Q-jet
http://quadrajetparts.com/secondary-well-plug-fix-t-21.html
On Fri, Feb 7, 2014 at 3:25 PM, mike foster <mafoster1@bellsouth.net> wrote:
>
>
> SeanKidd wrote on Fri, 07 February 2014 12:34
> > thanks Jim, I plan on using the original aux/main switch to control a
> relay for the pumps...the selector valve, despite being reliable (and most
> likely ) 40 years old is coming out. A momentary prime button adjacent to
> the ignition switch is in the scope. Despite resealing my Q-jet, it still
> leaks down, any opportunity to prevent cold cranking is a good one.
>
>
>
> If your carb is leaking down it is probably a blocked air passage causing
> the fuel to siphon out through the booster venturi.....at least that what
> caused Holleys to leak down when there was no evidence of gasket failure.
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Bruce Hart
1976 Palm Beach
Milliken, Co
GMC=Got More Class
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Bruce Hart
1976 Palm Beach
1977 28' Kingsley
La Grange, Wyoming
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| Re: [GMCnet] Electric fuel pump safety switch plumbing [message #239121 is a reply to message #239116] |
Fri, 07 February 2014 16:50 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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""What is desirable about a priming circuit to achieve instant starting of a cold engine? What happened to the concept of cranking the engine to build oil pressure before firing it off?
Just curious ""
I agree-I'm sure the timing is just by accident but when I crank mine with the electric pump off, it will start just about when the oil pressure gage shows good oil pressure.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: Electric fuel pump safety switch plumbing [message #239142 is a reply to message #239076] |
Fri, 07 February 2014 20:35 |
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WildBill
Messages: 232
Registered: January 2014
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The faster an engine starts the better. More bearing wear happens while cranking than running. If you could release the compression or had a pre oil system that would be another matter but how much pressure and volume do you think that pump can produce at 180 cranking rpm compared to an engine lighting off and going to 1200 rpm. Why do you think manufacturers have gone to synthetics and 5w/20 for instance.
Problem with running mechanical fuel pump and electric, you can't pull much
fuel through a rotary vane pump should the electric pump fail. Use a plunger/diaphragm electric in that case, they will free flow.
On my airboat I ran a 3position toggle switch with an emergency cover and oil pressure switch also wired to starter solenoid . Centre position was pump off, useful if flooded for some reason. Cover down was normal run position with crank prime through oil pressure switch and cover open and switch flipped up was hot to pump should you have an issue with a oil pressure switch or operate pump manually for mtc reasons, adjust fuel bowl levels, for, etc.
[Updated on: Fri, 07 February 2014 20:45] Report message to a moderator |
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| Re: Electric fuel pump safety switch plumbing [message #239144 is a reply to message #239142] |
Fri, 07 February 2014 21:02 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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| WildBill wrote on Fri, 07 February 2014 19:35 |
The faster an engine starts the better. More bearing wear happens while cranking than running. If you could release the compression or had a pre oil system that would be another matter but how much pressure and volume do you think that pump can produce at 180 cranking rpm compared to an engine lighting off and going to 1200 rpm. Why do you think manufacturers have gone to synthetics and 5w/20 for instance.
Problem with running mechanical fuel pump and electric, you can't pull much
fuel through a rotary vane pump should the electric pump fail. Use a plunger/diaphragm electric in that case, they will free flow.
On my airboat I ran a 3position toggle switch with an emergency cover and oil pressure switch also wired to starter solenoid . Centre position was pump off, useful if flooded for some reason. Cover down was normal run position with crank prime through oil pressure switch and cover open and switch flipped up was hot to pump should you have an issue with a oil pressure switch or operate pump manually for mtc reasons, adjust fuel bowl levels, for, etc.
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Well that's an interesting perspective and I need to think that through. However, the reason OEM's have gone to "low" viscosity numbers is for fuel economy. Synthetics are there due to high stress operation on certain but not all engines. As far as reaching relatively high oil pressure during cranking, that is a reality and anyone with an oil pressure gage can attest to that.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: Electric fuel pump safety switch plumbing [message #239150 is a reply to message #239076] |
Fri, 07 February 2014 21:22 |
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WildBill
Messages: 232
Registered: January 2014
Karma: 1
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Yes 5/20 fuel economy but lighter oil gets places quicker and low oil pressure during cranking results in metal to metal contact. A running engine doesn't have metal to metal contact between bearings and crank with sufficient oil supply. Know of lots of guys with 500 to 600 hp ls engines under severe duty that run 5/30 synthetic.
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