as many of you know, i've recently swapped an SE engine into my 85 GS. with that tonight, i swapped in an SE gas tank to accomidate the engine. upon hooking up the rubber lines coming from the tank to the hard lines on the car i noticed that there is a difference in fuel line size on the return line rubber to hard. i was thinking of using the current rubber line and clamp it to the smaller hard line. then i thought even more into it. am i going to see an abundant increase in fuel pressure if i use the 12A's fuel return line, engine to tank?

 

if it does increase the fuel pressure i may have to look into replacing the line with the correct line. luckily i happen to have the part number for the correct line..my guess is that its no longer available...

 

You need to upgrade the supply line to the SE size, which is approximately 5/16". 3/8" aluminum line works fine, then use the old supply line as the return.

 

^^excellent idea! thank you. if i cant get the line new from the dealer i'll make the line myself.

 

I doubt they would still have them listed. Making it yourself is very easy. I replaced both feed and return with some aluminum line I got from Summit. 25 feet was like $30 with shipping and was more than enough to remake both lines.

 

just go to a wrecking yard and jack the fuel lines of a SE. I did that with my old FB.

 

^^ i have never seen an SE in a bone yard. if i did, i'd buy the whole car. RX-7's are scarce as hens teeth in these parts. i buy every one i come across.

i may end up buying the aluminum roll from summit. it was suggested by a good friend of mine as well to do that last night.

 

One of the upgrades I did on the widebody was to replace the stock carbed fuel lines with 3/8" supply and return, in anticipation of a future TII swap. It's not hard, remove the old line and use it for a pattern. You will need to replace the mounting clips as the stock ones will crush the aluminum tubing. Found the replacement clips at a local parts store that specializes in large trucks/semis. They have a rubber sleeve that holds the lines quite well. The tubing came from the local speed shop for 20 bucks.

While bending the tubing, I found that careful use of the thumbs work better than the tubing bender I have for making the bends. At the ends of each tube I made a bulb flare to insure a good seal with the rubber fuel line and prevent the tube ends being crushed by the clamps. Any flaring tool can bulb the ends, practice on scraps first. All of your rubber fuel line must be replaced with FI rated hose and use the solid FI clamps, the worm clamps don't have the needed higher clamping pressure and chew up the hose.

The 25' roll of tubing leaves one with about 4-5' of extra tubeing if replacing both lines. If you have trouble locating the lines and clamps, I can pick them up locally and ship. I do have a set of SE lines, but shipping them is impractical and probably cost prohibitive.

 

^^thank you for the advice and parts offer Scott!! i do very much appreciate it. i'll call the dealer tomorrow with the part numbers and see if the lines are still available and if so, an eta. if not i may go the route of making the lines myself. if i am unable to locate the line, i will contact you and if your schedeule is free i may pay you to snag the line and ship my way.

 

Dave,

This is a good site to check to see if the parts still come up. :-)

http://www.mazda-parts.com/

 

^^awesome site!! thanks Doc!! according to that site, the lines are no longer available..

 

i didnt get a chance to call the dealer today...tomorrow. work was super busy..

 

well, i checked with the dealer and the lines are in fact no longer available. i will get some new line from summit as trochoid suggested and we'll go from there

 

Hey guys, be careful with aluminum fuel lines! If you have an injected car, make sure the psi rating is high enough! Recently I went to purchase aluminum lines and was warned that it was rated to only 35 psi. Find it hard to believe that aluminum is only rated that high, but I'd feel really stupid if I burn my car to the ground after being warned!

 

thank you for the advice!!! i'll be checking into that when i head to summitt this coming week!

 

Well, one of the guys already mentioned it, but it bears mentioning again - be sure you upgrade ALL of your fuel lines to FI-rated hoses.

I made the mistake of trying to use some standard fuel lines for carb's on my 84SE and within a month, I had fuel misting inside the engine compartment from pinhole leaks in the non-FI-rated plumbing.

It's important, and would be a shame to see a 1st Gen bite the dust because of an engine bay fire. HTH,

 

LongDuck, thank you for drilling that into my head. it is a pleasure to see you posting again! i will definatly make sure i get the proper line. all of the rubber hoses that i have replaced thus far have been replaced with F.I. rated hose. i.e. feed and return lines in the engine bay and the three lines on the gas tank. when i do a job i want it done right the first time. if it takes me another couple of weeks to aquire and run the new fuel lines then so be it. i just want the car to be put together correctly and since i'ver never converted a 12A car over to the S3 EGI 13B this is something new. i enjoy the challenge.

 

Can't wait to see pictures of it when you get it done. Take care,

 

thank you! here is the thread containing some current pics of the car:

https://www.rx7club.com/1st-gen-general-discussion-207/finally-got-my-l6-project-796342/

tomorrow i will upload the pics i took tonight of the interior and the wiring. the interior is 90% reinstalled.

 

as for trochoid's reccomendation on the fuel line:

here's a pic of the roll of 3/8" aluminum fuel line that i bought:

 

i must say that i really liked workng with the aluminum fuel line! easy to bend and flare. i used my current 5/16" feed line and used the 3/8" aluminum line as my return.

 

So, what's left? Are you close to ready to go?

 

the parts that need to be installed to finish the car are the fuel pump, exhaust center section (which i have to custom build because i do not have one), bleed the brakes and clutch, change the trans fluid, install the hood..after attempting to remove the rest of a bolt that broke off... hood goes on today

oh and pray that the engine is good

 

Can you squeak by with the smaller diameter line or do you need to upgrade to the larger size?

 

i'm hoping that the current 5/16" feed line will suffice for the needed fuel. i replaced my return line with the 3/8" and am using the current 5/16" supply line. i figured that since the fuel lines on the engine were 5/16" that it shouldn't be a problem.