Home » Public Forums » GMCnet » Re: [GMCnet] EFI vs Carb
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Re: [GMCnet] EFI vs Carb [message #326461 is a reply to message #326445] |
Wed, 29 November 2017 07:26 |
lqqkatjon
Messages: 2324 Registered: October 2010 Location: St. Cloud, MN
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i agree in-tank pumps are both harder to install, and harder to change. But when you talk to those that went that route it seems vapor lock is gone.
There are trade off's to all systems. A person has to make up there own mind and live with it.
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
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Re: [GMCnet] EFI vs Carb [message #326462 is a reply to message #326459] |
Wed, 29 November 2017 07:34 |
lqqkatjon
Messages: 2324 Registered: October 2010 Location: St. Cloud, MN
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I have dealt with numerous electric fuel pump failures.
Funny about chevy astro's. We changed quite a few. I remember getting one replaced under warantee only to have our mechanic break the replacement trying to install the lock ring. That was a $400 whoops.
Once on a Chevy suburban.
Couple ford e-250's.
My 93 cherokee never had an issue. I did rip the wires off that once in the woods, then punched a hole in the gas tank a year later in that same woods. So had the fuel pump out twice on that. But my 98 jeep wrangler lost a pump as did a friend's 94 wrangler.
3-4 fuel pumps on my vw sand rail. Those I should not count, but I can think of a few after market fuel pumps that were installed in a gmc motorhome that went bad.
I also live where it is -30 some weeks in winter and 100 in summer. Winters are hard on fuel pumps.
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
[Updated on: Wed, 29 November 2017 07:36] Report message to a moderator
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Re: [GMCnet] EFI vs Carb [message #326464 is a reply to message #326461] |
Wed, 29 November 2017 08:18 |
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USAussie
Messages: 15912 Registered: July 2007 Location: Sydney, Australia
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G'day,
I intend to install low pressure in-tank pumps (7 psi) to feed a surge tank up front which can feed the mechanical fuel pump or a
high pressure FI pump. The surge tank will have a return plumbed into the 1/2 inch vent tube for the fuel filler.
1) cut off the tubes off a defective tank sender
2) drill a hole in the center of the tank sender
3) put a screw with a sharpened end through the hole and install in the tank(s)
4) raise the tank(s) into position
5) the screw will put a mark on the aluminum sheet that covers the Styrofoam insulation
6) drill a 1/8 inch hole up through the aluminum sheet, Styrofoam, and plywood floor
7) using the 1/8 inch hole as a guide cut a 6 inch hole using a fly cutter
8) using a router along the edge of the 6 inch hole create a step for a 1 inch thick plug with a stepped edge
9) cover the floor with high grade vinyl
10) carefully cut out the 6 inch hole in the vinyl and glue it to the plug
10) make a custom fit carpet to cover the area and bind the edges
This will provide access to the pumps should they require replacement.
Regards,
Rob M.
The Pedantic Mechanic
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808
-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Jon Roche
Sent: Wednesday, November 29, 2017 7:26 AM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] EFI vs Carb
i agree in-tank pumps are both harder to install, and harder to change. But when you talk to those that went that route it seems
vapor lock is gone.
There are trade off's to all systems. A person has to make up there own mind and live with it.
--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/
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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] EFI vs Carb [message #326465 is a reply to message #326033] |
Wed, 29 November 2017 08:53 |
JohnL455
Messages: 4447 Registered: October 2006 Location: Woodstock, IL
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My personal experiences with Mopar in tank pump assemblies in Jeeps is they are very long lived compared to most other high pressure in tank pumps in the industry, which are short lived. Back to the GMC carb vs EFI debate-- if the reason for doing it is vapor lock, that can be corrected by installing an external feed through low pressure pump near the Aux tank and opperated via the existing Aux seitch via a relay with total parts costs well under $100. I have found all the wrapping and insulating a futile exercise. VL occurs before the mech pump in my opinion. Flip the switch and it's fixed every time. Also a well set up Qjet will start smoothly, transition cold to warm seamlessly and be very dependable. The only reason I would go to EFI is if I lived or drove a lot at altitude. It can't add air density but can pull fuel automatically at altitude keeping the engine more in the correct range to make the most of the thin air
John Lebetski
Woodstock, IL
77 Eleganza II
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Re: [GMCnet] EFI vs Carb [message #326474 is a reply to message #326033] |
Wed, 29 November 2017 12:15 |
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GMC Jimmy
Messages: 199 Registered: September 2016 Location: Niagara, Ontario
Karma: 2
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Thanks again everyone for your input.
John, Vapor Lock is one reason for considering EFI, the main reason is peace of mind for all-around driving. I live in Ontario, Canada, not much in the way of altitude in my area although I plan to drive to California in the spring.
I would like reliability, I realize there are challenges with both systems and that a properly tuned carb and distributor can address my concerns. I wasn't looking for a reason to spend two thousand dollars for an EFI set-up, I simply understood that an EFI system could be a more efficient and a potentially less troublesome route... everyone has their own opinion and experience with each.
My initial post asked for real world experiences rather than anecdotal opinions so I could base my choice on practical over theory. I
was directed to FaceBook as there is a group that discusses the Fitech set-up in the GMC motorhome, unfortunately I'm not a FB guy.
The quest continues,
Thanks,
Mike
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Re: [GMCnet] EFI vs Carb [message #326480 is a reply to message #326464] |
Wed, 29 November 2017 14:49 |
lqqkatjon
Messages: 2324 Registered: October 2010 Location: St. Cloud, MN
Karma: 5
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Rob-
2 quick things.
Do you know anybody who has cut the holes in the floor and what diameter and have r+r there fuel pumps through that hole??
I see that option talked about, and good in theory, I never heard how well it worked out in real life. I keep thinking you need a really big hole to manouver the fuel pump in and out of the tank, as well as getting the lock rings twisted and in place square and proper. Not saying it cant be done, but when I have looked at accessing the fuel senders 2-3 " below the floor, i wonder how big of a hole is needed to service?
2nd item is when I have had fuel tanks down it is more then obvious where to drill up. The last coach I did, i hole sawed out the foam, and drilled up into carpet with a 1/4" bit. You wont need to lift the tank to mark anything from bottom.
If you look at my photos you will see the factory already has a hole for senders. At least on my 75 and the 77 i did tanks on.
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
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Re: [GMCnet] EFI vs Carb [message #326481 is a reply to message #326480] |
Wed, 29 November 2017 15:23 |
bdub
Messages: 1578 Registered: February 2004 Location: Central Texas
Karma: 5
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I have 6" holes in the floor rabbited out to 7" on top 1/2" so the cover
won't fall out. I had to put on a new 2" piece of fuel resistant hose to
couple the fuel pump to the output tube. My first one disintegrated after
a couple of months and left me dead on the side of the road. Yes, I
switched pumps to pull from but that pressure went straight into the rear
tank because the pump connection wasn't there to stop it! Anyhow, I was
able to easily pull out the pump and sender assembly, repair, and
re-assemble without any trouble. Even with the o-ring seal.
bdub
On Wed, Nov 29, 2017 at 2:49 PM, Jon Roche wrote:
> Rob-
>
> 2 quick things.
> Do you know anybody who has cut the holes in the floor and what diameter
> and have r+r there fuel pumps through that hole??
> I see that option talked about, and good in theory, I never heard how well
> it worked out in real life. I keep thinking you need a really big hole
> to manouver the fuel pump in and out of the tank, as well as getting the
> lock rings twisted and in place square and proper. Not saying it cant be
> done, but when I have looked at accessing the fuel senders 2-3 " below the
> floor, i wonder how big of a hole is needed to service?
>
> 2nd item is when I have had fuel tanks down it is more then obvious where
> to drill up. The last coach I did, i hole sawed out the foam, and drilled
> up into carpet with a 1/4" bit. You wont need to lift the tank to mark
> anything from bottom.
>
> If you look at my photos you will see the factory already has a hole for
> senders. At least on my 75 and the 77 i did tanks on.
>
> --
> Jon Roche
> 75 palm beach
> St. Cloud, MN
> http://lqqkatjon.blogspot.com/
>
> _______________________________________________
> GMCnet mailing list
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bdub
'76 Palm Beach/Central Texas
www.bdub.net
www.gmcmhphotos.com
www.gmcmotorhomemarketplace.com
www.gmcmhregistry.com
www.facebook.com/groups/classicgmcmotorhomes
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Re: [GMCnet] EFI vs Carb [message #326482 is a reply to message #326480] |
Wed, 29 November 2017 15:30 |
bdub
Messages: 1578 Registered: February 2004 Location: Central Texas
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Oh and don't bet the farm on those existing cutouts in the insulation being
perfect fit for the tanks. Both mine were off about a half inch.
bdub
-----Original Message-----
From: Gmclist On Behalf Of Jon Roche
Sent: Wednesday, November 29, 2017 2:50 PM
2 quick things.
Do you know anybody who has cut the holes in the floor and what diameter and
have r+r there fuel pumps through that hole??
I see that option talked about, and good in theory, I never heard how well
it worked out in real life. I keep thinking you need a really big hole
to manouver the fuel pump in and out of the tank, as well as getting the
lock rings twisted and in place square and proper. Not saying it cant be
done, but when I have looked at accessing the fuel senders 2-3 " below the
floor, i wonder how big of a hole is needed to service?
2nd item is when I have had fuel tanks down it is more then obvious where to
drill up. The last coach I did, i hole sawed out the foam, and drilled
up into carpet with a 1/4" bit. You wont need to lift the tank to mark
anything from bottom.
If you look at my photos you will see the factory already has a hole for
senders. At least on my 75 and the 77 i did tanks on.
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
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bdub
'76 Palm Beach/Central Texas
www.bdub.net
www.gmcmhphotos.com
www.gmcmotorhomemarketplace.com
www.gmcmhregistry.com
www.facebook.com/groups/classicgmcmotorhomes
www.facebook.com/groups/gmcmm
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Re: [GMCnet] EFI vs Carb [message #326492 is a reply to message #326033] |
Wed, 29 November 2017 17:51 |
JohnL455
Messages: 4447 Registered: October 2006 Location: Woodstock, IL
Karma: 12
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Mike, if you want piece of mind--you can't beat a Qjet. As far as efficiency, I have never seen a post here about how they get better MPG with EFI. Have seen several posts about dead in water with EFI or orphaned systems with no parts and support.
John Lebetski
Woodstock, IL
77 Eleganza II
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Re: [GMCnet] EFI vs Carb [message #326498 is a reply to message #326493] |
Wed, 29 November 2017 19:46 |
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USAussie
Messages: 15912 Registered: July 2007 Location: Sydney, Australia
Karma: 6
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Wally,
Thanks for responding to this thread, I didn't realize that the tanks were as far forward as they are. I really like the self
adhesive floor tile idea.
I note you've used what appears to be 3/8' flareless fittings to connect the senders to what appears to be Poly Armour tubing, I
have Swagelok 3/8" flareless to 38 degree male stainless steel fittings. The flareless connection would connect to the sender
fittings and the flared connection to the Poly Armour tubing.
How did you connect the lines that go across the top of the tank to the lines that go up the side of the coach in the frame rails? I
plan on having some braided stainless steel flex hoses made up for that purpose.
Regards,
Rob M.
The Pedantic Mechanic
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808
-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Wally Anderson
Sent: Wednesday, November 29, 2017 5:53 PM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] EFI vs Carb
lqqkatjon wrote on Wed, 29 November 2017 14:49
> Rob-
>
> 2 quick things.
> Do you know anybody who has cut the holes in the floor and what diameter and have r+r there fuel pumps through that hole??
> I see that option talked about, and good in theory, I never heard how well it worked out in real life. I keep thinking you need
a really big
> hole to manouver the fuel pump in and out of the tank, as well as getting the lock rings twisted and in place square and proper.
Not saying it
> cant be done, but when I have looked at accessing the fuel senders 2-3 " below the floor, i wonder how big of a hole is needed to
service?
>
> 2nd item is when I have had fuel tanks down it is more then obvious where to drill up. The last coach I did, i hole sawed out
the foam, and
> drilled up into carpet with a 1/4" bit. You wont need to lift the tank to mark anything from bottom.
>
> If you look at my photos you will see the factory already has a hole for senders. At least on my 75 and the 77 i did tanks on.
We made floor access for in tank pumps. 1/8 aluminium plates recessed to floor level over a 6 inch hole. Self adhesive floor tile
over it. Marked hole
location while the tanks were out and I could see where the senders actually were by rub marks.
http://wallyandsue.blogspot.com/2014/07/floor-plates-for-access-to-fuel-senders.html
http://wallyandsue.blogspot.com/2014/07/floor-plates-for-access-to-fuel-senders.html
HTH
--
Wally Anderson
Omaha NE
75 Glenbrook
Megasquirt III injection
Bob Stone hydroBOOOOST
Manny reaction arm system
Branscombe Kelsey Hayes park brake
http://wallyandsue.blogspot.com/
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
_______________________________________________
GMCnet mailing list
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] EFI vs Carb [message #326508 is a reply to message #326498] |
Wed, 29 November 2017 21:08 |
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wally
Messages: 643 Registered: August 2004 Location: Omaha Nebraska
Karma: 5
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Rob, I used Dorman nylon fuel tube like newer cars and trucks use OEM. Those Dorman fittings are made to go from steel tube to their nylon tube. Same scheme to connect the forward end.
I did put external check valves in both pump lines as I had read of others who had issues if a pump check sticks open or a line comes off in the tank leading to an instant stop.
So far so good.
USAussie wrote on Wed, 29 November 2017 19:46Wally,
Thanks for responding to this thread, I didn't realize that the tanks were as far forward as they are. I really like the self
adhesive floor tile idea.
I note you've used what appears to be 3/8' flareless fittings to connect the senders to what appears to be Poly Armour tubing, I
have Swagelok 3/8" flareless to 38 degree male stainless steel fittings. The flareless connection would connect to the sender
fittings and the flared connection to the Poly Armour tubing.
How did you connect the lines that go across the top of the tank to the lines that go up the side of the coach in the frame rails? I
plan on having some braided stainless steel flex hoses made up for that purpose.
Regards,
Rob M.
The Pedantic Mechanic
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808
-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Wally Anderson
Sent: Wednesday, November 29, 2017 5:53 PM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] EFI vs Carb
lqqkatjon wrote on Wed, 29 November 2017 14:49
> Rob-
>
> 2 quick things.
> Do you know anybody who has cut the holes in the floor and what diameter and have r+r there fuel pumps through that hole??
> I see that option talked about, and good in theory, I never heard how well it worked out in real life. I keep thinking you need
a really big
> hole to manouver the fuel pump in and out of the tank, as well as getting the lock rings twisted and in place square and proper.
Not saying it
> cant be done, but when I have looked at accessing the fuel senders 2-3 " below the floor, i wonder how big of a hole is needed to
service?
>
> 2nd item is when I have had fuel tanks down it is more then obvious where to drill up. The last coach I did, i hole sawed out
the foam, and
> drilled up into carpet with a 1/4" bit. You wont need to lift the tank to mark anything from bottom.
>
> If you look at my photos you will see the factory already has a hole for senders. At least on my 75 and the 77 i did tanks on.
We made floor access for in tank pumps. 1/8 aluminium plates recessed to floor level over a 6 inch hole. Self adhesive floor tile
over it. Marked hole
location while the tanks were out and I could see where the senders actually were by rub marks.
http://wallyandsue.blogspot.com/2014/07/floor-plates-for-access-to-fuel-senders.html
http://wallyandsue.blogspot.com/2014/07/floor-plates-for-access-to-fuel-senders.html
HTH
--
Wally Anderson
Omaha NE
75 Glenbrook
Megasquirt III injection
Bob Stone hydroBOOOOST
Manny reaction arm system
Branscombe Kelsey Hayes park brake
http://wallyandsue.blogspot.com/
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
_______________________________________________
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Wally Anderson
Omaha NE
75 Glenbrook
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Re: [GMCnet] EFI vs Carb [message #326510 is a reply to message #326508] |
Wed, 29 November 2017 21:30 |
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Wish I'd a used those check valves.
bdub
On Nov 29, 2017 9:14 PM, "Wally Anderson" wrote:
Rob, I used Dorman nylon fuel tube like newer cars and trucks use OEM.
Those Dorman fittings are made to go from steel tube to their nylon tube.
Same scheme to connect the forward end.
I did put external check valves in both pump lines as I had read of others
who had issues if a pump check sticks open or a line comes off in the tank
leading to an instant stop.
So far so good.
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
bdub
bdub.net
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Re: [GMCnet] EFI vs Carb [message #326514 is a reply to message #326508] |
Wed, 29 November 2017 22:29 |
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USAussie
Messages: 15912 Registered: July 2007 Location: Sydney, Australia
Karma: 6
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Senior Member |
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Wally,
I want to use Poly Armour and put it on the outside of the frame because I'm hoping to plumb the water that condenses on the A/C
evaporator to the fuel line and the latent heat of vaporization will cool the fuel.
Regards,
Rob M.
The Pedantic Mechanic
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808
-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Wally Anderson
Sent: Wednesday, November 29, 2017 9:08 PM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] EFI vs Carb
Rob, I used Dorman nylon fuel tube like newer cars and trucks use OEM. Those Dorman fittings are made to go from steel tube to their
nylon tube. Same scheme to connect the forward end.
I did put external check valves in both pump lines as I had read of others who had issues if a pump check sticks open or a line
comes off in the tank leading to an instant stop.
So far so good.
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
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] EFI vs Carb [message #368535 is a reply to message #326498] |
Sun, 23 January 2022 11:16 |
Ken M
Messages: 32 Registered: December 2019 Location: Redding, CA
Karma: 0
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Member |
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USAussie wrote on Wed, 29 November 2017 17:46Wally,
I note you've used what appears to be 3/8' flareless fittings to connect the senders to what appears to be Poly Armour tubing, I
have Swagelok 3/8" flareless to 38 degree male stainless steel fittings. The flareless connection would connect to the sender
fittings and the flared connection to the Poly Armour tubing.
Regards,
Rob M.
Hi Rob,
I’m resurrecting an old thread here… I am working on adding hard lines to the top of my tanks. I have purchased some of the swagelok that you have often recommended in various postings. I also have the polyarmor line… my question is - what kind of fitting should be used to connect the two, in order to facilitate separating the two if needed. I am adding in tank pumps, and will be cutting an access hatch in the floor. So I’m needing a good way to separate the swagelok to hardline in the event that I have to work on the fuel pump. Do I just use some sort of 3/8” union or??? Do you have a link to a particular Union that you’d recommend?
1975 - 26’ Eleganza II
Unsure of what upgrades may have been done. I'm working on sorting that out in the coming months.
Ken Morefield - Redding, CA
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Re: [GMCnet] EFI vs Carb [message #368536 is a reply to message #326498] |
Sun, 23 January 2022 11:49 |
Ken M
Messages: 32 Registered: December 2019 Location: Redding, CA
Karma: 0
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Member |
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USAussie wrote on Wed, 29 November 2017 17:46Wally,
I note you've used what appears to be 3/8' flareless fittings to connect the senders to what appears to be Poly Armour tubing, I
have Swagelok 3/8" flareless to 38 degree male stainless steel fittings. The flareless connection would connect to the sender
fittings and the flared connection to the Poly Armour tubing.
Regards,
Rob M.
Hi Rob,
I’m resurrecting an old thread here… I am working on adding hard lines to the top of my tanks. I have purchased some of the swagelok that you have often recommended in various postings. I also have the polyarmor line… my question is - what kind of fitting should be used to connect the two, in order to facilitate separating the two if needed. I am adding in tank pumps, and will be cutting an access hatch in the floor. So I’m needing a good way to separate the swagelok to hardline in the event that I have to work on the fuel pump. Do I just use some sort of 3/8” union or??? Do you have a link to a particular Union that you’d recommend? http://www.gmcmhphotos.com/photos/member-galleries/p68417-swagelok2polyarmor.html
1975 - 26’ Eleganza II
Unsure of what upgrades may have been done. I'm working on sorting that out in the coming months.
Ken Morefield - Redding, CA
[Updated on: Sun, 23 January 2022 11:58] Report message to a moderator
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Re: [GMCnet] EFI vs Carb [message #368543 is a reply to message #326033] |
Sun, 23 January 2022 18:12 |
Bullitthead
Messages: 1411 Registered: November 2013
Karma: 5
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Senior Member |
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GMC came with Weber Edelbrock carb when I got it...noticed the hatch was crushing the air cleaner but still made it home from Danville OK. Drove it around town twice before swapping out the 600CFM Weber for the Quadrajet I had on my Bronco II V6. Runs nice, smooth, and have to be slow taking off in the rain going right. Even with the 3.07 F.D. And doesn't crush the air cleaner (which also came from the Bronco II).
Anyway, I went and bought a '69 Firebird and drove it up from Florida back in 2019. Came with a Holley 750 and corresponding Edelbrock intake. Terrible gas mileage, terrible fumes, reasonable power, didn't start right up when cold, and didn't run worth a fart until it was warm. Hood also trying to crush air cleaner. I knew I was going to change that carb before I bought that car but it ran good the day I got it.
After it's introduction to cold, damp Virginia, driveability became worse every ride and finally decided to put the Quad on there, like from the factory, but this meant changing the manifold since I could not use an adapter, just like on the GMC (because of extra height).
Gotta bench full of Quads, so bought and swapped manifold using crossover block plates (have not done this on GMC yet)and proceeded to play musical carbs using stock on hand and had one that really agreed with the engine. It came off my boat, and had no PCV or power brake vacuum ports. Started right up, ran like crazed cocroach in full escape mode. Decided to get a rebuilt Quad from EBAY, bad move, assembled from mismatched parts (airhorn not right for main body)and no returns. Found correct parts in collection and assembled working carb. Put on car and would not run right, figured I didn't get the rebuild right, but couldn't see what was wrong. Got another rebuilt quad, this time from JEGS. Really pretty, matched parts, replated butterflys, polished exterior, same $300. as the one from EBAY.Started right up, ran 8 seconds and quit. then repeat, holding/pumping throttle until it was warm but still would not run right. CLUE: only pulling 7 inches of vacuum at idle, NO vacuum leaks, smoked it to be sure. Finally took a functioning carb off other Firebird and tried that, could not adjust it to run even though smooth as glass on other engine (these are both 350s).
Well, rowing across the fuel induction river I was now halfway to the price of fuel injection, so do I keep plugging/sinking with these carbs or row back and get a different kind of boat? I chose the new boat and ordered the F.A.S.T. system since it was advertised as fitting the Quad manifold I had installed. I have decided that the P.O. put too big of a cam in there and the injection removes the variable fuel delivery at low RPM due to the low vacuum.
It's wonderful, starts right up, lopes a little until I load it going up the hill, and then I have to be careful to not tear up the gravel driveway. System comes with its own external H.P. pump that I am feeding off the stock mechanical pump. They want the pump lower than the tank and that isn't happening until the front of the car. Might be a little power drop-off at full throttle right now, but it's still real quick the 100mph, good enough to get me arrested so I'm just liking it right now. It was expensive, but at least I can now drive my antique car without a half-hour prep. And hardly any fumes from unburned fuel, actually cleaner than the GMC.
Now I see the price has gone up $400. !!! I just got it back in December for $1467...ridiculous,price gouging, but here is a link:
https://smile.amazon.com/gp/product/B016V2BB3U/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1
Terry Kelpien
ASE Master Technician
73 Glacier 260
Smithfield, Va.
[Updated on: Sun, 23 January 2022 18:15] Report message to a moderator
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