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-   -   -6 AN fuel line install? (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/6-fuel-line-install-968638/)

88_N/A_GXL 09-06-11 10:48 PM

-6 AN fuel line install?
 
I've been searching around the forum and I haven't quite been able to find a definitive guide on how to do a -6 or -8, or whatever size really, fuel line install. I was hoping somebody would be able to point me in the right direction or tell me how?

I'm finally getting around to fixing up my 7 that's been sitting for a while with a snapped line and would love to know. Eventually I do have big plans for it and I know I'm gonna need bigger lines down the road, so I figure be prepared and know what to do now, then start. Measure twice, cut once comes to mind. :lol:

PvillKnight7 09-06-11 11:02 PM

Nothing RX-7 specific about your question.

http://www.inlinetube.com/
http://www.aircraftspruce.com/menus/to/tubing.html
http://www.summitracing.com/
http://www.amazon.com/Fasteners-Plum.../dp/0879384069

SirCygnus 09-06-11 11:35 PM


Originally Posted by PvillKnight7 (Post 10776858)
Nothing RX-7 specific about your question.

nice way to not help the guy out, douche.

this applies to s4 fuel rails only. s5 need more modification as they are not the same. you can get KG parts fuel rails to circumvent this.

https://www.rx7club.com/attachment.p...hmentid=147380

Evil Aviator 09-07-11 06:06 AM


Originally Posted by SirCygnus (Post 10776902)
nice way to not help the guy out, douche.

Actually, PvillKnight7 is right, there is not a specific method to do this. The diagram that you posted does not address the hard lines that go under the car, fuel filters, fuel pump(s), and fuel tank/cell, which are all going to be custom.

The OP needs to be more specific about the intent of his car if he wants more specific guidance. Since the OP did not specify the power level, fuel metering method, fuel delivery method, or racing class requirements, I will defer him to the Aeromotive Power Planning website for general guidance:
http://aeromotiveinc.com/power-planner/

A search of the internet will yield various techniques for installing AN fittings and how to bend and flair hard line. Also, you may want to replace the brake lines at the same time.

arghx 09-07-11 08:11 AM

I can tell you right now that the splitter method is perhaps helpful but certainly not necessary for sane power levels. I have been running my 6AN lines in series (like stock) for years.

My best advice would be not to overbuild your fuel system too much because it can be an expensive and time consuming headache. Dual fuel pumps, fuel cells, parallel rails, add up fast. If you plan on running a hybrid turbo then forget it, at most you can install an aftermarket FPR, fuel pump and injectors and you will be fine. That's unless you are really interested in the look of stainless steel lines for aesthetic purposes.

PvillKnight7 09-07-11 09:32 AM

Plumbing a fuel system is a bit overwhelming if you've never done it. There are a lot of decisions that aren't outlined in any single post or write up I've seen. I have a folder on my computer that's full of pics of fuel systems and each fuel system is different. Everyone has their own method of developing and installing a fuel system...some are really bad. Some are good. Some are good and really expensive.

Aluminized steel lines will probably out last any project and they're easy to bend and flare. Much cheaper than SS or running braided lines from the tank to the engine. The Parker 37 degree flaring tool is expensive but it's a good investment if you like restoring cars.

One learning experience I had was discovering Earl's tube mate fittings, which are compression fittings used to go between hard-line and soft line, are not rated for fuel injection pressure.

There is also the potential issue of using the wrong fuel filter and burning out the fuel pump.

88_N/A_GXL 09-07-11 12:27 PM

Specifically, I eventually want to go N/A 20b, for specific horsepower, I'll just throw a dart someday and build for that and run larger lines as I start doing that. I just figure 6AN for now as I hear that is close to stock.

More specifically even, it's just the connections between line and pump, and wherever up front it connects, I don't know how I would go about connecting. I do know how to flare and bend tubing that's not the problem. I guess I've just never had a chance to really sit down and study how the stock line connects to the pump as compared to how a 6AN line connects, mainly because I've never seen a 6AN line fuel system.

Would I need a different pump or could I connect a 6AN line to a stock pump for now? That I guess is the main question for now. I could also be rambling as I am sitting in class right now as I type this.

Edit: As I look at the parallel rail picture, does the underbody main line run straight up to the y-block in the picture? If so, I could do that, just the pump connection I'm still not sure on.

PvillKnight7 09-07-11 12:47 PM

1 Attachment(s)
I'd budget $500 for an all new fuel system. If you know what parts you need, keep an eye on e-bay and the classifieds. This stuff is expensive.

-6 AN will be adequate. Run hard lines for the feed and return under the car. Flare the ends and use tube sleeves and tube nuts. Then you can use a -6AN male to whatever connector.

https://www.rx7club.com/attachment.p...1&d=1315417436

-6AN aluminized steel hardline
tubemate tube sleeve
tubemate tube nut
-6AN male to male connector
-6AN female to -6AN hose end
Russel braided -6AN fuel hose


On this project, I used weld on -6AN male fittings on the feed and return at the tank but there are better methods. MIG isn't the best method of welding on the fittings either. It's hard to weld on the small radius of the hard line going into the tank.

https://www.rx7club.com/attachment.p...1&d=1315417961

Another tip: don't mount the FPR on the firewall or at idle and low rpms you will hear the pulsing of the injectors through the firewall. It's a little annoying to me. I'd prefer to mount the FPR on the engine or at least use sound isolating rubber mounts like the kind on the AC line brackets.

88_N/A_GXL 09-07-11 01:05 PM

Is weld on fittings the only way to go? I also plan on an fpr delete.
Thanks for the info and pic though.

PvillKnight7 09-07-11 01:20 PM


Originally Posted by 88_N/A_GXL (Post 10777533)
Is weld on fittings the only way to go? I also plan on an fpr delete.
Thanks for the info and pic though.

You can use bulk head connectors. More fittings. More money.

https://i12.photobucket.com/albums/a...installed1.jpg

I've never heard of not using a FPR. How does that work?

88_N/A_GXL 09-07-11 01:34 PM

My bad, got it switched with an fpd. Oops. How would the bulkheads work in that setup then? Would you just run a line down or what? It confuses me.

PvillKnight7 09-07-11 01:51 PM

1 Attachment(s)

Originally Posted by 88_N/A_GXL (Post 10777567)
How would the bulkheads work in that setup then? Would you just run a line down...

Yes. That's one method. This isn't my pic...forget which member posted this but I saved it because I think it's a fine solution. Obviously he ran dual pumps and has a custom tank access plate but the idea can be applied to the stock tank access plate with the single pump.

https://www.rx7club.com/attachment.p...1&d=1315421123

88_N/A_GXL 09-07-11 02:52 PM

Hot damn, I think I'm all clear now with what to do. If only I knew which pumps those were, or is it kinda standard on some pumps to come with threaded fittings?

RENESISFD 09-07-11 03:01 PM

1 Attachment(s)
Those are most likely Bosch 044






John

PvillKnight7 09-07-11 03:40 PM

In-line pumps like the Bosch 044 have threaded female fittings.

http://www.summitracing.com/parts/VPN-GSL392/

So you would need something like a 10mm x 1.0 male to -6AN male connector.

Rob XX 7 09-07-11 03:51 PM

those are bosch pumps, and good luck getting fittings for them to use with stock lines, bit of a pain in the ass that turned out to be

you cannot possibly get 2 of these pumps through the stock cover, you would need to fabricate a custom cover and backing plate, by the time you did that you would be better off just having the stock tank sumped

http://robx-7.nopistons.com/d/4779-1/fpump+001.jpg

PvillKnight7 09-07-11 04:52 PM


Originally Posted by Rob XX 7 (Post 10777758)
those are bosch pumps, and good luck getting fittings for them to use with stock lines, bit of a pain in the ass that turned out to be

I don't know the bosch thread pattern but summit or pegasus racing doesn't have the male to nipple fitting you wanted for your pump setup in the pic above?

88_N/A_GXL 09-07-11 05:00 PM

I guess I thought in-line pump meant external to the tank. Learn something everyday haha. And to think, I've been passing up looking at inline pumps.

Rob xx 7, I didn't plan on two pumps, at least for now, or running it to a stock line, I was planning on bulkhead connectors like PvillKnight7 showed in both his pictures, to 6AN lines all the way up to the rails, or at least until I can't run a metal line anymore.

Rob XX 7 09-07-11 05:29 PM


Originally Posted by PvillKnight7 (Post 10777813)
I don't know the bosch thread pattern but summit or pegasus racing doesn't have the male to nipple fitting you wanted for your pump setup in the pic above?



nope, I could either order a entire kit from some guy in Florida or New Jersey, which I didnt need, or order the single fitting from australia and wait 2-3 weeks for it to show up at about $38

I had mine welded up at the local hose shop for like $20
The pumps usually come with the AN fittings but if you want to adapt to the stock fuel system somewhere thats where the problem lies

you want my advice it would be to go with the bosch pump now, it offers the most room for upgrades especially if you ever want to go E85, calculating that E85 requires 30% more fuel remember any pump you read about, like my old pump that said good for 500hp, is now only good for 350. I seen this first hand on the dyno with my own car.

88_N/A_GXL 09-07-11 05:52 PM

I do plan on E85, as I have about 6 stations within 10 miles that sell it and it's almost $1 cheaper, but that's injectors and such that I'm not worried about that right now, unless stock injectors would run it? I just want to get this car up and running. It had it's fuel line snapped like I said, so I figured while I'm at it just start on down the slippery slope.

Edit: Any pumps you guys would recommend over 80gph/300lph? Just for informational purpose, and just incase I happen to need more fuel than that. Don't get me wrong, I've heard a lot about the 044, but sometimes we get power hungry lol. And 350hp, for some like me, could potentially just be an appetizer. I'll just have to see after the 20b, if that's enough to satisfy.

Edit 2: Any recommendations on how long of a run I would need? It doesn't need to be specific, but I don't want to just buy 20' of line just to do that one for now. All I'm looking at for now is getting her running.

PvillKnight7 09-07-11 06:12 PM


Originally Posted by 88_N/A_GXL (Post 10777821)
I guess I thought in-line pump meant external to the tank.

I might have used the wrong term. I do know some tanks must be submerged for cooling and internal lubrication when they run or they can burn up. Others can survive in the air.

If you really think you'll need more than one 044 pump you might want to check into surge tanks and maybe even mechanical pumps:

http://www.fastecracing.com/fuel.html
http://www.watermanracing.com/

-6AN might be too small.

Rob XX 7 09-07-11 06:34 PM

I wouldnt do -6an lines, if you are going to the trouble and expense go larger and be set for the future.

The stock line from the tank to the filter is the last of my stock system

A walbro or a supra pump will be good, but remember what I said about E85- that pump will be no good once you take that step.

I bet for now to get the car running you could buy a used stock TII or even a NA pump, try to upgrade the fuel system once and be done with it when the time comes.
I built the system for 500hp on pump fuel and now with E85 in the tank I have had to change out my pump and my 1600's because they are maxed

88_N/A_GXL 09-07-11 06:47 PM

So, -8 or -10? I'm just afraid of running too rich. I personally won't have a problem with using a new pump later down the road, this will probably be a LONG project, but e85 on a 13b n/a, possibly s5 rotors, and bigger injectors will probably be about as far as I'm gonna go right now.

SirCygnus 09-07-11 08:37 PM

then keep the stock fuel system.

Evil Aviator 09-07-11 10:02 PM


Originally Posted by SirCygnus (Post 10778141)
then keep the stock fuel system.

+1

If you install a fuel system that pumps too much fuel for the engine, then the FPR will bypass a lot of it, which heats up the gasoline, causing about a 10% decrease in power. To stop this from happening, you would need to install a fuel pump controller, which is currently priced at about $150-350.

A basic NA 20B or high-output street NA 13B is about 200-220bhp, which is supported by the stock lines just fine.

E85 is shit. It loses about 30% power and about 30% gas mileage vs. gasoline, plus it is more corrosive.

88_N/A_GXL 09-07-11 11:24 PM

E85 is no more corrosive than gas Evil Aviator. Why else would we be running 10% blends of that instead of methanol, which is quite corrosive. And, if you tune e85 properly you can get better gas mileage and/or more power, not saying it's easy on a rotary, but I've done it on a couple builds before, but that's changing compression ratios and cams and such that is not possible on a rotary. But, if one was inclined and had deep enough pockets, I think they could get <10:1 rotors and run on a very lean mixture.

Then again, this is all a matter of opinions too and how you drive. You can't say you've never heard that how you drive has one of the biggest impacts on mpg. If your shooting for big numbers there, it is possible.

Also, this is why I was saying a -6AN line now and the Walbro GSL392 pump, or something smaller? I have a feeling it's all rusty in there anyways.

Evil Aviator 09-08-11 01:22 AM


Originally Posted by 88_N/A_GXL (Post 10778364)
E85 is no more corrosive than gas Evil Aviator.

When you read the E85 propaganda that says that it is not corrosive, they mean in a chemical sense, which simply means that pure ethanol is not an acid. The problem is that ethanol is very polar, and as such it attracts water and other contaminants into the fuel system where they can cause damage. While studies are continuing in this realm, the main offender seems to be the chloride ions that are in ethanol blended fuels, which are shown to cause pitting corrosion, galvanic corrosion, and stress corrosion. Gasoline is very non-polar and does not exhibit this problem to a significant degree. If you look in your RX-7 owner's manual, you will see that the stock fuel system is rated for not more than 10% ethanol, and no methanol. Modern flex-fuel vehicles have fuel systems specially designed to resist deterioration caused by the fuel contaminants. If you insist on using that shit fuel, then when shopping for aftermarket fuel system components you should make sure they can handle E85, although most of them do nowadays.


Originally Posted by 88_N/A_GXL (Post 10778364)
And, if you tune e85 properly you can get better gas mileage and/or more power

There is no current technology that allows E85 to produce more power than gasoline in an NA engine. Ethanol simply has less energy content and a lower AFR, and that is just plain physics.

Rob XX 7 09-08-11 06:04 AM

you want to make more power and not run race fuel the answer is simple, fuel economy isnt the issue at that point. Want fuel economy then buy a Prius

Switch the map over and run regular gas again if you wish- its not for everyone but its certainly not shit

88_N/A_GXL 09-08-11 07:48 AM

The water problem with blended mixtures is only because everything separates at mixtures under ~e30, might be a little off on the blend. And anything above that point and you can't saturate the ethanol enough for the mixture to separate or even cause any problems. What do you think iso-heet and heet, the fuel line deicers and water removers, are made out of? Last I checked isopropyl alcohol, chemically c3h8o, and ethanol is c2h6o correct? I don't know about you but those seem to be pretty similar to me, yet one is marketed for REMOVING water from a fuel system so that it does not cause any harm.

And, yes I do know e85 on an NA will not give any more power than gas, but when it's ~$1 cheaper per gallon, you do the math on which one is more economical.

Sadly Rob XX 7, we don't have a Prius, we have a Civic Hybrid if I really was concerned about mpg. It may not be the Prius, but it sure as hell gets better mileage than the 7.

87RXsexy7 09-08-11 10:47 AM

Just thought i might as well share my knowledge on ethanol based fuels.
1st off everyone who said it is less efficient is totally correct - ethanol contains less energy than gasoline so for the same gallon you get fewer miles. While these may be less expensive after you've run your tank, ethanol is a subsidized production last i checked and subsidizing is detrimental to economic stability because it is supporting industry that shouldn't exist according to the market. You pay for subsidy through taxes. And the price of corn goes up.
2nd to produce ethanol from plant materials, the use of other fossil fuels is far greater than in the production of regular gasoline. This means that you aren't even being green because you are polluting the earth even more by using a fuel that pollutes in production and combustion = worse for the environment. Not to mention you are driving a sports car...

Also i don't know about these compounds that clean out water from your gas tank but it sounds like they do exactly what Evil Aviator said ethanol does: collect water. Only difference is typically you aren't running them for fuel. So they collect water out instead of collecting it constantly. I dunno. Could be wrong on that but makes sense to me.

88_N/A_GXL 09-08-11 11:16 AM

To your first, yes we all know it has a lower energy content, but that does not mean it is less efficient. It all depends on how it's used (ie. higher compression definitely ups the efficiency). That's like taking a Prius and acting as if your foot is made of lead, yea it's gonna be less efficient, but only because it's being used improperly.

To your second, I agree with you that current mass production techniques for making ethanol are detrimental to the environment, but there are better ways. They just need to up the scale on current eco-friendly ways to numbers that would actually matter to the world.

Also, ethanol and water are miscible, meaning they mix at all proportions. But, as gas is added, it tends to break up that miscibility and that is why we get corrosion in the fuel system. As I said before, anything above ~E30, and there isn't enough gas to affect the miscibility of the ethanol and water. And, on a side note, last I heard, water is great for carbon cleaning our motors and as long as it's not sitting separated in my tank and lines and such, I'm going to use it.

RotaryEvolution 09-08-11 11:48 AM

i don't really understand the idea behind E85 on a naturally aspirated engine unless you are running a peripheral port with a standalone.

-6 with the stock lines will push up to about 450 wheel horsepower with E85, when you go to -8 or -10 then the stock lines become the bottleneck and you still retain the same peak range for the fuel system.

you're going for extreme overkill, i'm not sure who you have been talking to but a turbo pump, stock lines and even the stock FPR are plenty for most n/a builds.

Rob XX 7 09-08-11 11:49 AM

Its funny hearing RX7 owners talk about the environment, these cars are filthy.

I could give a rats ass about how E85 is made, all I care is I can run more boost and not come home smelling like I was mowing grass all day, the car emits almost no emissions now which makes my wife and I happy after a day with the top down. Our taxes pay for it, so what- less money in the hands of people who despise us the politicians and the lobbyist will always line their pockets its better then shiek a' stinky pitts shitting in one of his 38 gold plated toilets. while counting his money

For a car I drive way under 1000 miles a year I don't really care if I get less fuel economy, it doesn't effect me in the slightest, think I care if a day's drive cost me $20 or $24? its the least of my ownership expenses

88_N/A_GXL 09-08-11 08:03 PM

Karack, would all that work on a 20b also? How about 26b? If I get that adventurous one day. Then again both of those on E85? Someday I may boost, but as of right now that is currently out of my budget. I want something that will be fairly easy to upgrade down the road, hence all the AN fittings and plumbing right now. I don't want to have to completely rip everything apart just so that it can keep up with my upgrades down the road. I figure a nice semi-large pump for now up to a 8 or 10AN bulkhead right angle fitting on the tank, then run 6AN line under the car. That way, if I need more fuel for just bolt-on's and maybe a Power FC, I don't need to pull the pump and change the bulkhead, I could just run a larger line.

Correct me if I'm wrong but an 8 or 10AN line should be fairly sufficient even into boost on a 20b or 26b right? That's what I'm basing most of this project on right now, future "plug-n-play" upgrade ease. Even though I know to some of you this may seem pointless, but I know where I want to go someday and this just seems logical to me, and I don't have money just laying around to bigger and better fuel pumps, lines, injectors, etc. everytime I want more power.

Sorry if any of that sounds like I'm coming off as an a$$, I really don't mean to.

RotaryEvolution 09-09-11 04:55 PM

know how many people come in my shop asking about even the cheaper alternative which is a 20B? quite a few, wonder how many eventually go with a 20B? almost none(only one so far and he has dumped well over $20k into his FD in the past several years while it takes up garage space). for a 4 rotor expect to be knee deep into your car for at minimum $40k by the time it's all said and done, of which you'll only see a fractional return on your investment.

i'd worry about overdoing the fuel system once you actually need it, otherwise you're just spending money for absolutely nothing right now.

believe it or not we're just trying to save you money and headache.

Rob XX 7 09-09-11 05:24 PM


Originally Posted by Karack (Post 10780558)

i'd worry about overdoing the fuel system once you actually need it, otherwise you're just spending money for absolutely nothing right now.

believe it or not we're just trying to save you money and headache.

this


people are always very motivated, but unless you have very deep pockets and the commitment for the project practically none of these 3 rotor projects ever come to life

PvillKnight7 09-09-11 05:33 PM


Originally Posted by Rob XX 7 (Post 10780590)
this


people are always very motivated, but unless you have very deep pockets and the commitment for the project practically none of these 3 rotor projects ever come to life

Or if they do they break and/or get parted out in the for sale section. :/

RotaryEvolution 09-09-11 05:34 PM

anything over a 2 rotor is impractical, i know of many 3 rotor cars but i never see them because they simply are driven about 2-3 days a year.

what's the point having a car that no one sees?

if/when i ever do convert to a 3 rotor i would build it to be driven, not a garage ornament. my TII has 220k miles on it and looks better than the day i bought it 10 years ago.

88_N/A_GXL 09-09-11 07:04 PM

My 3 or 4 rotor will be a daily driver, I'm not big into keeping cars in garages. Like I said though, this is going to be a long project as you guys have pointed out that it takes a bit of money, that I don't have laying around. Maybe I'll pass my ASE tests and can get a nice paying job and specialize in rotaries, specifically pre-renesis, on the side, cuz we all know how common they are anymore.

RotaryEvolution 09-09-11 08:13 PM


Originally Posted by 88_N/A_GXL (Post 10780708)
Maybe I'll pass my ASE tests and can get a nice paying job and specialize in rotaries, specifically pre-renesis, on the side, cuz we all know how common they are anymore.

all i can say is best of luck, been doing it for 10 years and barely hang on day by day. renesis is the only way a shop these days will survive and even then i have a hard time convincing people that their 8 is worth spending $3k on for a rebuilt motor/install. and plenty of people tell me i'm too cheap, yet more often than not people scratch their head and dig into their mothballed wallet to usually not be seen again.

it's only just now that the first models are coming out of warranty, as everyone was taking their cars to the stealership to have the basics covered by the warranty.

Rob XX 7 09-09-11 08:45 PM


Originally Posted by Karack (Post 10780788)
all i can say is best of luck, been doing it for 10 years and barely hang on day by day. renesis is the only way a shop these days will survive and even then i have a hard time convincing people that their 8 is worth spending $3k on for a rebuilt motor/install. and plenty of people tell me i'm too cheap, yet more often than not people scratch their head and dig into their mothballed wallet to usually not be seen again.

it's only just now that the first models are coming out of warranty, as everyone was taking their cars to the stealership to have the basics covered by the warranty.

and no more RX8s, if nothing replaces them who knows what the future will bring for these cars

RotaryEvolution 09-09-11 09:17 PM


Originally Posted by Rob XX 7 (Post 10780808)
and no more RX8s, if nothing replaces them who knows what the future will bring for these cars

you're probably looking at the last mass production rotary engine which was the 8(renesis 13B).

Rob XX 7 09-10-11 07:08 AM

if your business plan is to fail then cater to rotary engines, cars and their owners are getting cheaper and cheaper.
Best to leave it as a side biz and pick and choose your customers carefully, more mature understanding customers versus whiny kids with shoestring budgets

88_N/A_GXL 09-10-11 07:57 AM

Like I said, rotaries on the side. One day I'll own my own shop hopefully.

cbrock 09-16-11 10:20 PM

If you run E85 plan to find hose with liners for alcohol or stainless hard line.


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