nelapse

iTrader: (17)

I am planning on upgrading my fuel pump and wiring, however my new made exhaust is keeping me from dropping the tank. I would have to cut my new exhaust in order to drop the tank.

This is a touchy subject... some people think it is ghetto rigging some people think it is perfectly fine.

I was thinking about cutting out a panel on my parts car. Then make a template then on my formula cut a square hatch. on the edges, glue a rubber gasket. Then make a panel that screws on so it seals the square and can be removable.

I understand there is some risk of cutting. I would use a sawzall instead of a cut off wheel to reduce sparks. I will also fill the gas tank up full blast to reduce vapor. I will also put a nomex blanket over the tank while cutting.

I personally think there is more risk welding my exhaust next to the tank than cutting this panel. Post your opinions. If you have pics of this modification please share.

Please visit the poll.

PROCHARGED

Cut a panel for the fuel pump! There are lots of people who will bash this-but that is what I am doing when I put my new fuel pump in come spring.I can fab up a alum.panel in the fire shop to go over the hole.So it does not bother me. Do a .on this mod.

nelapse

iTrader: (17)

This is mostly for a poll. I personally think it is safe and a good idea for a modified car. That sees the track and the road. Anyone else want to chime in?

1991Camaroz28

you own the car. do what you think is bes. my personal opinion is that you should only modify the car if you think it is an upgrade to the vheicle..

firebirdjosh

iTrader: (1)

Good luck getting a sawzall in there- it's a tight fit between tank and body. I personally wouldn't do that to my car.

Wheel Spin

I think it is a worthwhile mod, but must be done properly, all safety factors taken into consideration. I just replaced my stock in-tank fuel pump, it was a PITA. I did not cut an access plate when the tank was off, but that is the proper time to do it. I plan more rear suspension upgrades, will probably drop the tank again and do the access panel mod. I STRONGLY suggest you don't attempt the mod with the fuel tank in place.

Edit: I have to add my exhaust is still slip-fit (Borla), I have left it that way intentionally for future mods....

89_ho_rs

I like the idea of the "easy acsess pannel" but as Wheel Spin stated You should NOT do it with the fuel tank in place. One wrong move and thats it. I would drop the tank and cut the hole. yes it is a long and pita process but it would be the last time you would have to drop the tank for a fuel problem.

Pocket

iTrader: (24)

Opinion here...

If you ever resell the car it will immediately be labled hacked up

If you race it or whatever and need alot of access to teh fuel pump then yeah id say cut a hole

nelapse

iTrader: (17)

I have welded subframes, and a cage waiting to be put in... no matter what it is a hack job. If anyone buys a car with a cage they usually have an idea of modifications as this. As cutting the panel while there is a tank...

What is the difference of doing that and welding your muffler right next to the tank? That muffler produces more sparks and hotter ones.

89_ho_rs

my opinion is that when you are cutting the door you are cutting right above the tank your sparts are falling right on the tank . if any fuel has spilled or anything. it is right there. also if you go too far with a sawzall or a cutting wheel you are in the tank. imo it is a bad idea to cut with the tank in place. but I would still do the door.

Quasi-Traction

My personal opinion is that its fine. Its your car. If you plan on putting in a cage anyways, this is a minimal concern. It'll will probably never be back in stock form for some restoration **** down the road to curse whoever "ruined this perfectly good F-body".

I cut the whole strip out of my old 84 sport coupe I parted to repair this problem for someone else's camaro. If you do cut the piece out use a grinder for some pilot cuts and then a sawzall for the rest. You have about 3" inches at the tighest spots and as much as 5" where the tank contours away from the body. I did it with the tank in halfway full and there were no explosions/burns/lost body parts. If you decide at all to do it, leaving the tank in and using a sawzall is fine, Just be cautious.

firebirdjosh

iTrader: (1)

Vapors rise.

Do you realize how close the body is to the tank? It's a tight squeeze, where as the muffler may be far away depending where you're actually welding.
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By the way, purging the tank is nice if you want to do it the right way.

nelapse

iTrader: (17)

filling the tank to full capacity would be safer than a drained tank. Less vapor.
I have made up my mind. If I cover the tank with a nomex blanket I would not be that worried.

Fastcamaro87

If you want to do it i would suggest using an air nibbler. no sparks, no danger of hitting the tank. just drill your 4 corner holes, and go to town. I did this on my 87, and then cut a panel from a parts car that overlapped the hole by about 1" , put down a bead of sealer, and a couple of machine screws. The las time i replaced the pump it took me about 30 minutes. Also if you do a nice job nobody will be the wiser. summit sells access doors for this type of thing, that would finish it off very nicely.

Stephen

iTrader: (12)

Timing is funny My pump died today, so guess what I'm doing tomorrow? Cutting the access door!

I'll take pics and such, as I go. It's my understanding though, that there is about 1/4" to 1/2" between the tank and the floor. I guess I'll find out tomorrow! I'll be sure to measure with pics, so there can be no doubt. Dad'd gonna help, but get aggrevated as hell, with me stopping to take pics, and write notes! LOL Oh well. I wanna write up a "How to" on this.

6" square hole? 10" square?

Wheel Spin

I did not take pics of mine off, but search around here. IIRC, there are four steel lines fixed permanently to the top flange that comes off the tank. For the mod being discussed here, they will have to be cut and rubber hose inserted to be able to utilize the access door. Not hard to do, but another safety (dangerous) thing to consider.

I still recommend the tank be removed when attempting this mod, once it is off you will better comprehend what is needed with the access door.

jstoltz

iTrader: (16)

not a horrible idea if done right. like stated I would also just remove the tank. yeah it is about a 2.5 hr job but since this is the fab section you could make the time worthwhile. the chrysler new yorkers have a plate in the trunk factory few others also. I myself would definitely think of a better way to attach the screws though because of the risk of puncturing the tank if you were in an accident. on the ones I saw they used studs welded in and then nuts to attach the plate. you could use regular weld in studs and just cut so there is one exposed thread after the nut when the panel is tightened down to attach that way there is no risk to the back seats if you still have them in there and no one would say a word. also use edge molding around it with a rust inhibitor and a gasket on the removable access door. I think if it was done like this it would definitely be worthwhile. also for the sending unit I would either do a quick connect conversion like the fords (this is what I would do) but then again if you were going to do all this why not just remove the in tank pump and go to an external pump. just my

83 Crossfire TA

iTrader: (2)

I think it’s absolutely insane that these cars don’t have one. Most imports and anything that has a tank located above anything else has them, I don’t know why f-bodies weren’t designed with them from the get go.

Not thrilled about the idea of screws… they leave sharp points that the tank can bounch off of and get punctured. Rivets would work better and only take a few seconds longer to take out then screws the next time around, I’ve used riv-nuts for this before (threaded sleaves that are riveted into the hole to act as a nut for the back of a machine screw), then just size the screw so it doesn’t stick out past it.

How exactly do you plan on getting a nomex blanket in there or having enough room to use a sawzall? For that matter if you’re worried about sparks, the teeth on a sawzall blade spark as then cut and so do the motor brushes.

I’d radius the corners to prevent any chance of tearing in the corners, and I’d make sure that whatever you put on top of it as a panel is well fastened. If you have the tools it would be nice to put a bead around the opening also, maybe even setting the “door” inside the bead, but not 100% necessary. I’d do it carefully with an angle grinder, of course I cut stuff with an angle grinder reglarly and can practically do it with surgical precision. If you’re worried about that then just step down, die grinder with a cutting wheel or even a dremel will do it, just slower.

Nope, vapors fall.

For that matter, with anything resembling reasonable ventilation you shouldn’t have enough vapor build up to burn anything, even if the fuel lines were cut and open, or if you cut into a line.

Are you serious??? I suppose if you really want you can fill the tank with some CO2… either from a pressurized CO2 bottle or a little dry ice, but that would just prove a big waste of time.

jstoltz

iTrader: (16)

what about using dzus fastners? anybody think it would work?

nelapse

iTrader: (17)

[QUOTE=83 Crossfire TA;3145470]I think it’s absolutely insane that these cars don’t have one. Most imports and anything that has a tank located above anything else has them, I don’t know why f-bodies weren’t designed with them from the get go.



Not thrilled about the idea of screws… they leave sharp points that the tank can bounch off of and get punctured. Rivets would work better and only take a few seconds longer to take out then screws the next time around, I’ve used riv-nuts for this before (threaded sleaves that are riveted into the hole to act as a nut for the back of a machine screw), then just size the screw so it doesn’t stick out past it.



How exactly do you plan on getting a nomex blanket in there or having enough room to use a sawzall? For that matter if you’re worried about sparks, the teeth on a sawzall blade spark as then cut and so do the motor brushes.


QUOTE]

Well I have decided to use bolts and anchor nuts. I do not want to rivet it because I want to make this removable in the future. So 4 bolts long ways 3 bolts shortways with anchor nuts that clip in the holes drilled.

They make some nice short sawzall blades that would work great, Or maybe I could use an aircutter, which is like a one handed sawzall. You can easily slip in a blanket, at least on my car. I can still drop the tank a little bit and let it sit on the rear while I perform this mod.

8492bird

This link (with pics and measurements) is for a fourth gen, but should be applicable for a thirdgen also. Not sure what he finally did for a cover though.

http://www.worldisround.com/articles/12533/index.html

And yes this is a very touchy subject - see this link

https://www.thirdgen.org/forums/tpi/...ghlight=access

nelapse

iTrader: (17)

It is funny, 80% according to the poll think it is a good idea. If you research previous threads like these. They are all closed. Because one or two people go off on a tangent and flame everyone saying it is a hackjob. I have seen some really nice ones.

After I cut my square I will add a rubber weatherstripping to the edges, that will serve as my gasket for the new panel. What about the metal lines. What is a proper solution for those. What I read, says that the lines will most likely need to be cut. Is the high pressure rubber lines all we have for options?

Wheel Spin

They will have to be cut. High pressure rubber hose is an option, or use compression fittings. Go read the TGO thread linked just above your last post.

jstoltz

iTrader: (16)

I would use AN line and just get a 37 degree flaring tool
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found this also I think it would be ok and it comes with low profile attachment hardware.

http://store.summitracing.com/partde...5&autoview=sku

not sure if it will be big enough though. but nelapse with you fab skills should be no problem anyway. have you decided to make anything else anytime soon or everything at a halt so far.

nelapse

iTrader: (17)

Actually last night I fabbed me up a nice aluminum console lid/ cover

The foam ones rip alot so I fabbed up a nice thick .060 aluminum plate that fits the contours. I was thinking about either making it a lid, or cutting two large holes in it to make adjustable drink holders. I will get a pic in a few. I will PM you so we stay on topic.

You are right though, that access cover is no where near big enough.

jstoltz

iTrader: (16)

good deal. hopefully this doesn't get locked out. however you end up doing it post up some pics I am curious to see how you do it. I will probably do mine sooner or later but I am thinking about dzus fastners and a strip under it so no chance of puncturing the tank at all.

nelapse

iTrader: (17)

dzus fasteners are great. I am an aircraft mechanic and we have them everywhere. The only thing is to mount a mounting nut/ pin for a fastener can be a pita and would not be worth it to me. I am going to use the weather strip and a thick aluminum panel. I am just thinking whether or not I want to make that panel a hinge or bolted in with anchor nuts.

jstoltz

iTrader: (16)

that's true. I think I would make it completely removable since you would probably not be getting into it all the time. I would just do studs like the chryslers then and just leave a little bit of thread and get plastic cover quick access screws I found them somewhere but don't remember where. I would do edge molding instead of weatstripping though just because it won't deteriate. also a little cleaner looking in my opinion. or make it exactly like the moroso piece I posted and make it about 12x12

nelapse

iTrader: (17)

The weather stripping looks like what we have for the rear hatch. It will slide into the edges and have that thick squishy rubber that will make a great seal.

Spike-Z

iTrader: (4)

Best pic I have of mine.

laiky

I did this a while back when all the posts were getting closed due to the hack job battles.

1) you can do it with the tank in. Use a cut off wheel but don't penetrate farther than necessary to sever the metal.

2) You will need to cut almost to the back seat (as far as the deck is flat).

3) You will need to separate the lines under the car.

4) Open the tank, remove the pickup/pump assy.

5) Cut the metal lines (stagger the cuts)

6) using an an union flare the lines and test fit the unions

7) replace the pickup and reconnect with the unions, then reconnect under the car.

**** Note *** the tubing used for fuel lines in these cars is welded, there is a raised seam inside the tubing. If using a single flare as in an AN 37 degree. You must polish the ridge out after flaring, a pointed tootsie roll works well. DO NOT do this on lines with fuel or connected to a fuel supply. Make SURE to thououghly check for leaks after your done.

89pontiac400

iTrader: (1)

I did this and I'm glad. I wish I would have done it sooner. I used a shear air tool to cut a hole in the sheet metal. then when you get access to the fuel pump you need to cut the lines I used a lock cutter to limit sparks. next I cut the crimped ends of with a cutoff wheel the lines to the motor you don't need to worry about but the ones to the tank made me nervous. If the tank is full you won't kill yourself though. I filled the lines with something to keep the sparks from entering the tank I think I used wood dowels. then just use high pressure hose to reconnect the lines. I just use speed tape to fasten it back up and it works great. I also keep a subwofer on top of it. I carry a spare pump and tools to change it so if it ever goes out agian I can change it in 20 mins on the sid eof the road. I also don't care what anyone thinks of it cuase I'll never sell it.

83 Crossfire TA

iTrader: (2)

You know, this was said in the other thread and I just don’t get it…. Drilling out a bunch of rivets will not take any longer then pulling out the same number of screws, what maybe 10 seconds per rivet? There is no reason why it wouldn’t be removable.

Dzus fasteners are nice, but contrary to what a lot of proponents of this are saying, the floor there is a stressed member, the car does get some strength from it and being basically a spring loaded fastener, dzus fasteners will never hold something rigidly/without moving.

It’s not a question of short blades…. Sawzall have 2-3” stroke lengths and there is only about 1” space between the top of the tank and floor. You’ll either be poking a hole in the top of the tank on every stroke or pulling out of the hole and bending the blade every time.

Just use a cutting wheel or some shears and quit ****ing around

laiky

[/quote] It’s not a question of short blades…. Sawzall have 2-3” stroke lengths and there is only about 1” space between the top of the tank and floor. You’ll either be poking a hole in the top of the tank on every stroke or pulling out of the hole and bending the blade every time.

Just use a cutting wheel or some shears and quit ****ing around[/quote]


Absolutely! The tank is sealed, the sawzall will be far more dangerous and messy. I cant remember if i hole sawed the corners or not. Either way the pilot bit is too long so you will need a very short one. This is good since as 83 points out the floor is stressed in this area.

found a pic, no hole saw used sorry!

laiky

won't let me upload!

https://www.thirdgen.org/forums/fabr...ever-just.html

TexasSilhouette

iTrader: (4)

I’m curious, are your fuel pumps failing so much that this is worth all the trouble? If you keep your fuel filter changed, your pump should go 150K+ miles. It takes me about 2 1/2 hours to change one if I take it easy and < 2 if I need to get it done. Don't take this as flaming, so don’t retaliate by berating me. If I were considering purchase of a car and saw the sender and floorboard were hacked up, I'd pass.

The rubber line adds the potential for leaks; the cuts in the floor add the possibility for water leaks and rust. If not a complete vapor barrier, exhaust and fuel (from leaky rubber lines) can use it as an entry. The cars with factory access had the pan shaped in such a way as to provide a positive sealing surface and reinforcement and even then many had rusted screws that would round off or break when you tried to use them.

This is just not a "mod" for me.

So I am one of your eight votes against, I would not do it myself. My $.02

But remember, you asked.

A full tank and/or one purged with an inert gas (CO2 or Argon) would be safer to work around than an empty or low one. Do not disconnect any fuel line or gas cap until all cutting is done. Sawzall's and nibblers both produce sparks albeit at a much diminished level than an abrasive cutter. Use caution as if your life depended on it, as it does.

jstoltz

iTrader: (16)

I think I may do this next week if I do I will post pics. if done correctly it will be alot easier all around to do alot. true it isn't something that is normally messed with on a regular basis but if you are going to the track or car show and it happens to go out would you rather do it in around 20 mins or "duh I can drop the rear and exhaust and take anywhere from an hr to 3 hrs." this is the kind of hobby where easier and faster is always better. I love to work on cars but I hate to do retarded a** things to get them done. taking 5 steps to actually move one isn't my thing. I will probably brace around it to be on the safe side. and it will be a stock look. honestly by the time I finish it you won't know unless you know about these cars. I have seen them on unibody cars before and I thought the factory did a hack job but it did what it was intended to do. so to each his own but why make things harder???

MrDude_1

in the time it took me to read this entire thread, i would have the car ready to drop the tank, and have the first strap bolt completely out.


maybe im just a super awesome mechanic.... or maybe its because i realize that it just looks hard, but isnt.... but i can drop the tank and swap pumps in under a hour with hand tools.

sure, after the first time of cutting the hatch, its faster.. but i can honestly say, with all the GM pumps ive changed, i have yet to go back and swap one again after changing it.... (except for one, but i TOLD him not to use the crappy Autozone pump... it failed, and a month later we swapped it for a walbro... took a hour out of our day.)




totally ignoring the hole in the car issue... totally ignoring the fact that most people suck at fabricating and cutting.... and assuming you make a nice cover with radius corners and evenly spaced rivets, ect....



the bigger issue to me is the hardline connections... i dont like having rubber connections where i cant supervise them regularly... and i have yet to see a compression fitting under there that doesnt eventually leak from the stress of line movement... and like stated above, this type of fitting is a PITA to flare because of the way the tubing is made... if flared successfully, it may still form a crack over the area next to the weld on the flare.... so you want to keep an eye on it...

now, with a 4thgen tank, the lines connect to the top of the tank with snap connectors... so the lines are no big deal.. but i dont like the options available with the 3rdgen lines....

83 Crossfire TA

iTrader: (2)

Hole saw… use one with a removable pilot and cut it down so it’s only 1/8” or so past the teeth… I have a pilot bit that I bent, replaced but straightened that one and cut it down just for this kind of thing. Or if you can hold it steady or have access to a mag base drill press use it without a pilot.

Texas… Failing a lot… I’ve never had one fail in my own car. I have gotten 3 bad replacements in a row working on someone else’s car and the next time I’m monkeying around with this it will be to mess with a dual pump setup and I’m going to want access to the wiring and plumbing on and off to experiment, so I have _no doubt_ that I’ll cut a hole, and I have no doubt that my access panel will take this to a whole new level of **** retentiveness. Actually, I’ll probably do it when I have the axle and exhaust out of the car anyway, it’s not an issue of getting to it or dropping the tank, it’s an issue of what I want to be left with when I’m done.

Mr dude… it’s because you’re a cocky SOB.

And some 4th gens use rubber hose connections up there, and some use the push connects, depends on what year. For that matter I don’t see how it really makes a difference. All but the feed line you can get away with just putting a rubber hose on it and not even using clamps, I’d put clamps on the return “just in case” though.

In my case I plan on ditching the factory pressure line anyway and replacing them with 2 bulkhead fittings of sorts… and running 2 filter assemblies before y-ing the lines together. And mine WILL be fabbed correctly.

jstoltz

iTrader: (16)

I will probably do stainless line.

MrDude_1

i'll go along and agree with that.


and yea, by 4thgen i really was thinking of 99+ fbodies...

laiky

I did mine for many of the same reasons 893 did his, I retrofitted FI and didn't know what to expect. Was the Walbro any good (yes of course but i was unsure then) and will it be big enough? Will i have a sender issue with my 22 year old car? I don't have enough room in my gararge to remove the exhaust either. Just seems like a great mod for a hotrodder who is in it for the duration, if you can do it safely. I'm happy with my outcome.

8492bird

Just want to say Thank You! to everybody responding in this thread. This is probably the most civilized discussion on the subject on TGO yet, and that dreaded four letter word **ck (begins with "h") has'nt even been used.

nelapse

iTrader: (17)

Let me ask you guys something... Since we are talking about reliability eariler... walbro the most reliable? I am not down the bosch, I have seen a hundred people take them back when I had my second job at autozone.

TexasSilhouette

iTrader: (4)

Well, I think everything at VatoZone is defective so i just don't go there, ever.

EFF26

I think you should and here is why. I recently had to change my fuel pump and decided to cut an acess panel. I am glad I did. The NEW fuel pump I bought the motor would run but it would not pump. If I had dropped the tank and put that pump in and it did not work I would have been very mad. So I used a pair of air operated sheet metal nibblers. Did not have a problem at all. there is about 2 inches of clearence between the tank and the body. I went down to the local hose and fitting store and bought stainless steel compretion fitting for the fuel lines because I didn't like tha idea of using clamps and hose. After done I took a piano hinge and a thin piece of stainless stell and made a access door. Take soom RTV sealent and make a seal around the door for sealing and you are done. Like I said the first pump was bad and I had no way of knowing until I got it put back in. So I say do it!!

RBob

iTrader: (1)

And the welded seam is why single flairs are not to be used. Single flairs are ONLY to be used on seamless tubing.

On welded or seamed tubing, a DOUBLE flair is required. This prevents the seam from cracking. Check out the older vehicle fuel and brake lines. All used double flairs at 45 degrees.

I've stayed out of every 'cut a hole in the floor' thread for the simple fact that the single most important area: re-connecting the fuel lines, not one has yet to be done correctly.

RBob.

Fastcamaro87

forget the sawzall, and cut off wheels.

92rs365hp

I think its a good idea but should you drain the gas first??

laiky

I'm well aware of how it's "supposed" to be done. Since polishing the flare i now have a "seamless" line. Not advisable unless dry and disconnected from the tank but it is effectively "correct". The double flare is a crutch the auto industry uses because they like cheap tubing. I have not had an issue in going on 4 years.