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Fuel Neck Filler Mods?

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hey guys,

 

so I'm curious if any of you have modded any of your fuel filler necks to prevent fuel from splashing back when refueling? I would also love to have the modern filler necks where you can place the pump and leave it there. Im surprised no manufacture has created a filler neck to treat this issue..weird...lol

 

I Just ordered a replacement gas tank and sending unit (locally) and going to purchase a holley hydramat from summit so it'll be perfect time to do these mods. Im no welder so I'd prolly have to take it to a fab/muffler shop near by and see if they can help me mod one up.

 

I found a couple of threads from VMF that have done this Splash guard filler neck mod but no one has updated it ever since so Im kinda curious if it works or if it was a failed attempt trying to modernize the filler neck.

 

anyways, any ideas would be greatly appreciated.

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I suspect you ran across the same thread I did on VMF titled: "Fuel spilling / burping 67 & 68 Mustang", dated April 2008. He cut a slot in the fill neck 1 1/2" down and brazed in a plate with the inside diameter of the neck and a central 7/8" hole for the gas pump nozzle. At the bottom he had a 1/8 hole for fuel to drain back into the tank. From the posts I've seen there were generally good but varied results. Some people could fill with the nozzle on high with no problems and others had to keep it on low, but all said it improved the situation- which we all know to be terrible. It is my single biggest complaint about the car and has been since it was new.

 

I found fillernecksupply.com and this part that is $12.95 and intended to screw into the end of a modern filler neck:

Product Description

Screw In Automotive Cap Threads With Flapper Spec SAEj1114.
Applications: Fuel/ Gasoline.
Insert Outer Diameter: 1-7/8".
Cap Outer Diameter: 2.1/4"
Height: 1-3/8"
Part# NJ507090G2
Notes: Comes With Flapper. 
Material: STEEL.

These are designed to be pressed into a 2" OD filler neck with a .046" wall, and use a 1990-96 thread-on gas cap.

Our filler necks have a 2 1/4" OD but I think we may be able to cut a hole in the top flange to match this part. I think the flip cap would seal-up to it but since the tank was vented here be sure to vent it elsewhere.

I just ordered one- I'll let you know if it has possibilities.

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Wow, I've been curious about this as well ever since I read that thread on VMF a year or so ago.

 

I'm sure it is not just old Mustangs that have the problem ... we just have it worse than many old cars because our gas opening is surrounded by painted body surface.

 

You would think Scott Drake would be all over something like this.

 

Doug

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Just went to that web site Mach1 Driver mentioned and found it ...

 

post-14006-0-99653600-1455920992.jpg

 

http://www.fillernecksupply.com/fuel-filler-neck-cap-insert-screw-in-cap-gas-engine-NJ507090G2/#ProductReviews

 

 

If that could be modified to slip inside an existing neck (from the bottom) then tack welded in place up at the top, that just might be the ticket !!

 

Doug

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I suspect you ran across the same thread I did on VMF titled: "Fuel spilling / burping 67 & 68 Mustang", dated April 2008. He cut a slot in the fill neck 1 1/2" down and brazed in a plate with the inside diameter of the neck and a central 7/8" hole for the gas pump nozzle. At the bottom he had a 1/8 hole for fuel to drain back into the tank. From the posts I've seen there were generally good but varied results. Some people could fill with the nozzle on high with no problems and others had to keep it on low, but all said it improved the situation- which we all know to be terrible. It is my single biggest complaint about the car and has been since it was new.

 

I found fillernecksupply.com and this part that is $12.95 and intended to screw into the end of a modern filler neck:

Product Description

Screw In Automotive Cap Threads With Flapper Spec SAEj1114.

Applications: Fuel/ Gasoline.

Insert Outer Diameter: 1-7/8".

Cap Outer Diameter: 2.1/4"

Height: 1-3/8"

Part# NJ507090G2

Notes: Comes With Flapper. 

Material: STEEL.

These are designed to be pressed into a 2" OD filler neck with a .046" wall, and use a 1990-96 thread-on gas cap.

Our filler necks have a 2 1/4" OD but I think we may be able to cut a hole in the top flange to match this part. I think the flip cap would seal-up to it but since the tank was vented here be sure to vent it elsewhere.

I just ordered one- I'll let you know if it has possibilities.

 

 

Yeah, that was the thread I was looking at. I think even replied to that asking for a follow up or something.. but that was a few years ago.

 

I'm very surprised that no company has created a solution for this..especially, when we are trying to modernize our cars.

 

let us know how it works out, I would love to see a write up as well if you get around to it. I have even thought of cutting my filler neck in half and placing a metal plate and re-welding it back together.

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I received the part mentioned above and as usual I can't post pictures on this site, perhaps because of my Ubuntu operating system, so please see pictures and comments in the attached. BTW you can't attach files that are 15MB as this site states, this file was 9.1MB and wouldn't attach until I changed the resolution on all the pictures- it is now less than 400k!

mustang filler neck3.doc edit: see filler neck7 below

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Nice write up !!

 

If you were to chuck the insert in a lathe and turn down the 2.263" top flange (or remove it completely) do you think the 1.910" body diameter would be able to make it past the bend in the 2.160" ID neck ?? 

 

Might need to continue turning the insert once the flange is gone to shorten it so it can make the bend.   Of course once up and past the bend, there would be some slop between the ID & OD which might not be desirable. 

 

Ideally having the top flange turned down so it just slips in would be ideal, but that will likely not allow it to make the bend.

 

Just trying to avoid having to disassemble the neck !!

 

Doug

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Nice write up !!

 

If you were to chuck the insert in a lathe and turn down the 2.263" top flange (or remove it completely) do you think the 1.910" body diameter would be able to make it past the bend in the 2.160" ID neck ?? 

 

Might need to continue turning the insert once the flange is gone to shorten it so it can make the bend.   Of course once up and past the bend, there would be some slop between the ID & OD which might not be desirable. 

 

Ideally having the top flange turned down so it just slips in would be ideal, but that will likely not allow it to make the bend.

 

Just trying to avoid having to disassemble the neck !!

 

Doug

Hi Doug,

Dang I wish I had access to a lathe! I don't blame you for not wanting to remove the flange but it will give you much better access to weld if you do take it off. You would have about 0.102" total clearance in the bend if you turn the flange down to the body, so it should fit around the bend, but then you would have a pretty sloppy 0.125" gap all around at the top of the neck. You might be able to play with the flange dimension until it just squeezes around the bend and end up with somewhere around a .075" gap all around at the top. It only costs $18.20 with shipping to try.

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Might just have to buy a couple of them to experiment along side of you !!

 

I think you are right though that it will need to come apart.

 

Thought I had a couple of spare filler necks in my parts stock pile, but did not find any when I searched yesterday in the two places where I thought they would be.  

 

Don't want to take the one out of the car, so I'm going to have to look a little harder or order a new one up to play with if I really can't find a spare one here.

 

Doug

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Finally figured I would attempt this mod and the NJ507090G2 is now OUT OF STOCK at fillernecksupply.com.

CJP has the neck on sale for $15 and I had some RPM points to burn so I at least ways got a neck coming as well as a new hose.

Just sent them a message asking when they will be back in stock ... hopefully the insert is not permanently out of stock / obsolete now.

Doug

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15 hours ago, Mach1 Driver said:

Doug, I finished that project with good results. Its hanging around here in one of the threads, but I attached the write-up below so you don't have to search.

mustang filler neck7.pdf

Oh I've got a copy of your write up saved, it certainly was my inspiration to do further research.   Have since read through a few other threads on the subject ... one on StangFix that you also posted in ... that showed other people's methods, so I'm going to give this a shot.    Filler Neck Supply replied to my message and they say they have these on order and expect them to be available again in a few months.

What this hobby really needs is for someone like Scott Drake to step up and produce fill necks like this. 

Thanks !!

Doug

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20 hours ago, stangs-R-me said:

Oh I've got a copy of your write up saved, it certainly was my inspiration to do further research.   Have since read through a few other threads on the subject ... one on StangFix that you also posted in ... that showed other people's methods, so I'm going to give this a shot.

Good, I'll look forward to seeing your solution. My method required "no welding" since I don't have those skills or equipment. Please keep us posted.

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Just looked at 2 original filler necks, 1 1969, 1 1970. I can scrape a layer off outside close to where the rubber attached with my finger nail and get a shinny surface; just like how you can scrape off the battery terminals. I don't think you can scrape a shaving off (not pealing) with your finger nail if it was galvanized.

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I have two 69 filler necks and both of them are like aslanefe described. There is a soft type coating on them not sure what it is but is not a hard coating. The repo's are junk like Mach1 driver said, the repo seems to be painted with a gray paint that has an adhesion problem.  

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Got my new Scott Drake hose and the cheaper CJP version Filler Neck this week.

Filler neck appears to be "brazed" to the flange so I'm thinking the best way to go about this is to just heat it up enough to "Un-Braze" the two parts, insert the filler neck insert (modify if req'd so it slips in with a friction fit), braze insert into place, then re-braze the flange back on.

Plating on this CJP part appears to be ZINC rather than Galvanized.   Would bring it to a plater to I.D. for sure, have them strip existing plating off, do my modding, then bring back to them to them to re-plate it once I'm done with it.

This CJP neck DOES NOT have the "VENT-DENT"" in the flange like my OE one does so I would also have to try and duplicate this before brazing back together.   Anyone know if the more $$ Scott Drake version has the dent in it or not ??   Can't tell from pictures on CJP or SD sites if it is there or not.   I've also attached Brian Conway's pic showing this "dent".

Doug

 

SD Hose & CJP FF-Neck.JPG

FF Neck no vent dent like OE.JPG

FF Neck Vent Dent-Close up.jpg

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I am planning to do this as it really pisses me off when the fuel kicks back and get on my paint.

 

my plan was to reduce or remove the lip/flange so I can get it past the curve. 

I figured that I would drill 4-6 holes radially in the neck where I want the inser to go.

use a couple of the holes to hold the insert in place with screws and plug weld the other holes to hold the insert in place. Then remove the screws and plug weld those holes.

if there is any gap between the insert and the neck I figure that will be fine as it will allow venting and drainback. Should not get too much of a gap so should not negatively effect the splash back reduction

 

bob

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