Standard return fuel line with l28 turbo

[260z.76]

Hey as tital says will the stock return line be fine to use with a l28 efi turbo

 

Running a surge tank and wanted to know if the return line will keep up ot be to small

 

Will be in a 76 260z bus

[pauly_adams]

dont see why not mines fine but i  have a larger fuel pump

 

[RB30X]

Why are you worried if your 'return' line can keep up, surely your supply would be more important.

[nizm0zed]

because the return line is the potential weak point in the whole system, being the smallest diameter line.

From what i know of it, unless your planning on building a 500hp motor, your return will be fine.

 

Now that you have that answered, you can concentrate on making sure the pump, rail, injectors, pressure reg and feed line are all up to spec too.

[260z.76]

Thanks thats good

Yea i wanted to know if ill have to get a bigger return line just incase

[Retro Z]

I would upgrade it. Or use the standard evap line as your return instead.

 

I upgraded mine as i was having high fuel pressure and trouble starting sometimes as fuel was not returning fast enough on load..

 

Now running 3/8 for feed and the stock (5/16?) As the return. With the pickup from the bottom of the tank plug bolt.

 

Then again my l28 has a fair few bolt ons..so may work with stock, but going by what everyone on Hybridz says its not recommended.

 

Stock return is thinner than a drinking straw from one of them juice boxes

 

 

[jamo240]

I had both my L28 turbo and now RB25DET (435HP at the flywheel) plumbed like this:

 

- Lift pump draws fuel from standard 5/16 tank pickup and feeds into a 1 litre surge tank.

- Main Bosch 044 pressure pump picks up from surge tank via a 5/8 inlet to pump

- Feed to the engine goes through a new 3/8 feed line (reduce to standard RB 5/16 feed at the fuel rail)

- Return to tank goes through original 5/16 feed line (now a return line)

 

This setup works fine and I have never experienced fuel starvation or problems returnining the fuel to the tank via the 5/16 return.

 

Cheers

 

Jamo

[Retro Z]

I had both my L28 turbo and now RB25DET (435HP at the flywheel) plumbed like this:

 

- Lift pump draws fuel from standard 5/16 tank pickup and feeds into a 1 litre surge tank.

- Main Bosch 044 pressure pump picks up from surge tank via a 5/8 inlet to pump

- Feed to the engine goes through a new 3/8 feed line (reduce to standard RB 5/16 feed at the fuel rail)

- Return to tank goes through original 5/16 feed line (now a return line)

 

This setup works fine and I have never experienced fuel starvation or problems returnining the fuel to the tank via the 5/16 return.

 

Cheers

 

Jamo

 

So basically what i done..

 

What i found with the stock 3/16 return line. Is the car would run really really rich on idle as seen on the dyno at time of tuning. Was advised to change to 3/8 feed and use 5/16 (original feed) as return and problem went away.

 

 

[Zedman240®]

240Z's ahd a minature return line but I know the later 260's had a pretty decent return. I'm running a 260 return line with my efi (non turbo) with no problems..

[Six_Shooter]

I would upgrade it. Or use the standard evap line as your return instead.

 

I upgraded mine as i was having high fuel pressure and trouble starting sometimes as fuel was not returning fast enough on load..

 

Now running 3/8 for feed and the stock (5/16?) As the return. With the pickup from the bottom of the tank plug bolt.

 

Then again my l28 has a fair few bolt ons..so may work with stock, but going by what everyone on Hybridz says its not recommended.

 

Stock return is thinner than a drinking straw from one of them juice boxes

 

This is how I have mine set-up, 3/8" feed, used the original feed (8mm), as return, also pulling fuel from the tank drain plug.

[nizm0zed]

i would imagine that pulling from the tank drain bolt would be a real bad idea?

It'd be a higher risk of being snagged/damaged by debris causing a fuel leak and it'd be pretty effective and funneling any junk in the tank straight into your pump/filter setup. Especially if the fuel level was real low.

[Retro Z]

Maybe.. Has pretty good clearance as the tank curves up before the plug in which is a 90 degree fitting with a small tap lever.

Been done by many and no different to the many fuel cells also with the pickup on the bottom.

 

Also done the same on my ra28 Celica been running for years like that no problems..just start with a clean tank and have appropriate in-line fuel filters i guess?

 

For a racecar maybe not, but for a street car nothing would snag it unless you run over a basketball or something and if it does its a $5 peice of efi hose or at worse a new fuel tank.

[Six_Shooter]

My car has had this fuel pick up for about 5 years, never an issue. My entrance to my driveway is also pretty steep and it's never scraped or caught on anything.

[Zedric]

240Z's ahd a minature return line but I know the later 260's had a pretty decent return. I'm running a 260 return line with my efi (non turbo) with no problems..

I have a 76' 260z 2 seater and the return line might look OK but if you have a close look it has a tiny hole in the end of the steel line just after it swings around the rocker cover back to the tank. I'll take a pic and post.

[Zedric]

Here is a pic of the end of the fuel line.[/img]

[pauly_adams]

that is a cap, it can be removed or drilled out

[Zedric]

that is a cap, it can be removed or drilled out

Yeah, you can just cut it off. The point is why is it here in the first place. The only thing I could think of is a very crude fuel pressure regulator, since it is in the return line. I have a big problem at the moment because I have HS6 SU carbs and they have a return line from the fuel bowls and if they aren't returned to the tank without the restriction the front carby just pisses out fuel. I know it could just be a needle and seat problem but how do I know? These carbs aren't meant to be on this engine but the hitachi's didn't have a problem with this fuel pressure, so I'm thinking needle and seat in the fuel bowl.

[Ben]

That restriction is effectively the 'pressure regulator' for the OEM Hitachi setup.

 

I agree with those that have used the OEM feed as a return and fitted a new 3/8 feed. I have had starvation issues - but that was because I had to remove the surge tank and ran the fuel level too low. I'm now converting to a drain-plug setup, not sure if I'll fit a surge tank again - space is real tight now that the R200 is fitted, and I've got my Racor high-pressure filter at the back of the car too.

[Zedric]

That restriction is effectively the 'pressure regulator' for the OEM Hitachi setup.

 

I agree with those that have used the OEM feed as a return and fitted a new 3/8 feed. I have had starvation issues - but that was because I had to remove the surge tank and ran the fuel level too low. I'm now converting to a drain-plug setup, not sure if I'll fit a surge tank again - space is real tight now that the R200 is fitted, and I've got my Racor high-pressure filter at the back of the car too.

Like I said it's obviously a fuel pressure regulator setup. I don't think I would be comfortable with a drain-plug feed, although it's worked on motor bikes for god knows how long, but a bike tank is allot easier to keep debris free.