Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > 911 / 930 Turbo & Super Charging Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered
 
BoxsterGT's Avatar
 
Join Date: May 2004
Location: New Hampshire
Posts: 5,145
Porsche Crest



I can help shed a little light on this subject.......

The 74 model was the only year Porsche used white nylon tunnel lines, with a 10mm supply line to the rear pump and a 8mm return line to the tank. It was primarily a low-pressure system, with suction from the tank to the pump and low pressure return from the motor to the tank.

The exposure to heat generated by the exhaust & drivetrain turned these white nylon lines brown and they became hard and actually brittle, and often cracked when disturbed. They were a failure waiting to happen. Note right center of this photo below.....



Beginning with model year 1975, Porsche went to the Black Polyamide tube made by Cohline. This same type of tube is still used today for fuel systems by Porsche and most auto mfgs worldwide. It is practically bulletproof and will last the lifetime of the car when left alone and not burned by welding or drilled thru by unknowing mechanics installing fire extinguishers or race seats.

For model year 1976 Porsche went to a front pump location, and that meant high fuel pressures front to back. The condition of the rubber hoses before and after the tunnel lines and their connections became critical.

Now, 30 odd years later, these rubber hoses are failing and often the connections have rusted away. The modern fuels just make matters worse.

Fortunately, time and technology has brought improved E-85 rated rubber compounds, and for those of us with turbo power a hidden benefit....... a cooler mixture and "more boost".

I offer these same Polyamide tunnel lines with fittings at both the front and the rear....



....with E-85 rated hoses to fit just about any combination pump and filter and fuel system.

With my tunnel lines I include a M14 coupler to aid in pulling the new lines through as you pull out the old....



I am happy to answer questions by email, although I have been experiencing issues with my Verizon service and seem to miss the occasional message.

I ask your patience in this regard.

Len at Autosportengineering dot com


Old 04-12-2016, 06:01 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #21 (permalink)
Registered
 
onboost's Avatar
 
Join Date: Mar 2006
Location: Metro DC
Posts: 5,628
Quote:
Originally Posted by BoxsterGT View Post


I can help shed a little light on this subject.......

The 74 model was the only year Porsche used white nylon tunnel lines, with a 10mm supply line to the rear pump and a 8mm return line to the tank. It was primarily a low-pressure system, with suction from the tank to the pump and low pressure return from the motor to the tank.

Beginning with model year 1975, Porsche went to the Black Polyamide tube made by Cohline. This same type of tube is still used today for fuel systems by Porsche and most auto mfgs worldwide.

Len at Autosportengineering dot com

Len, thanks for chiming-in.. that's the name/term I was looking for Polyamide.. as opposed to "polyethylene." We upgraded to these as opposed to dealing with the old nylon line.
__________________
RGruppe #180
So many cars.. so little time!!

Last edited by onboost; 04-12-2016 at 06:33 PM..
Old 04-12-2016, 06:29 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #22 (permalink)
Smart quod bastardus
 
fredmeister's Avatar
 
Join Date: Oct 2002
Location: Baltimore, MD, USA
Posts: 2,238
Garage
Cool

Quote:
Originally Posted by BoxsterGT View Post


I can help shed a little light on this subject.......

The 74 model was the only year Porsche used white nylon tunnel lines, with a 10mm supply line to the rear pump and a 8mm return line to the tank. It was primarily a low-pressure system, with suction from the tank to the pump and low pressure return from the motor to the tank.

The exposure to heat generated by the exhaust & drivetrain turned these white nylon lines brown and they became hard and actually brittle, and often cracked when disturbed. They were a failure waiting to happen. Note right center of this photo below.....



Beginning with model year 1975, Porsche went to the Black Polyamide tube made by Cohline. This same type of tube is still used today for fuel systems by Porsche and most auto mfgs worldwide. It is practically bulletproof and will last the lifetime of the car when left alone and not burned by welding or drilled thru by unknowing mechanics installing fire extinguishers or race seats.

For model year 1976 Porsche went to a front pump location, and that meant high fuel pressures front to back. The condition of the rubber hoses before and after the tunnel lines and their connections became critical.

Now, 30 odd years later, these rubber hoses are failing and often the connections have rusted away. The modern fuels just make matters worse.

Fortunately, time and technology has brought improved E-85 rated rubber compounds, and for those of us with turbo power a hidden benefit....... a cooler mixture and "more boost".

I offer these same Polyamide tunnel lines with fittings at both the front and the rear....



....with E-85 rated hoses to fit just about any combination pump and filter and fuel system.

With my tunnel lines I include a M14 coupler to aid in pulling the new lines through as you pull out the old....



I am happy to answer questions by email, although I have been experiencing issues with my Verizon service and seem to miss the occasional message.

I ask your patience in this regard.

Len at Autosportengineering dot com

Awesome, thanks for doing this.

I will contact you if I need any parts in the future. so far I am not leaking fuel except thru the fuel head into the intake ports when on full throttle at the track.
__________________
1979 930 Turbo....3.4L, 7.5to1 comp, SC cams, full bay intercooler, Rarlyl8 headers, Garret GTX turbo, 36mm ported intakes, Innovate Auxbox/LM-1, custom Manually Adjustable wastegate housing (0.8-1.1bar),--running 0.95 bar max
---"When you're racing it's life! Anything else either before or after, is just waiting"
Old 04-14-2016, 09:54 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #23 (permalink)
Registered
 
Join Date: Aug 2004
Location: Maryland
Posts: 802
Garage
I just sprang a leak in the hose between rear pump outlet and fuel accumulator/fuel filter inlet. Len, I sent you a message, please check your inbox.

Thanks
__________________
Emery

1988 930 coupe - Silver Metallic
3.3L w/GT35R, B&B Headers, RarlyL8 muffler, TurboKraft IC, Tial WG, tecGT based phased sequential EFI & ignition, Wevo shifter/coupler, ...
Old 09-17-2016, 09:34 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #24 (permalink)
Large Member
 
krasuskyp's Avatar
 
Join Date: Nov 2001
Location: top of 3rd
Posts: 4,307
Garage
Len does not use PM, he only uses email. Text me at 860 490. 9808 and I will get you his address.

I just finished replacing my line from the pump to the through the tub line that I just got from Len. Took mere minutes.

Len's the man!
__________________
Paul... CT | '87 930 | '08 M3 6gang vert |
past:

| '07 S6 | '98 M3 vert | '01 M5 | '96 993 C2 cab | '05 S600 Sport - biturbo V12@Just Not Right 495rwhp / 612rwtq |
| '58 TR3A | '01 S8 | '95 S6 6gang | '88 M5 | '87 190E 2.3-16 |
Old 09-17-2016, 02:35 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #25 (permalink)
Registered
 
Join Date: Aug 2004
Location: Maryland
Posts: 802
Garage
I did get in touch with Len and have a complete set of replacement lines on the way. I plan to replace the rubber lines in the front all the way through the tub to the fuel filter.

It appears that the front lines are not threaded couplings to the lines that go through the tub, so there is no practical way to leave the through the tub lines in place when replacing the front lines, since the line would have to be cut.
__________________
Emery

1988 930 coupe - Silver Metallic
3.3L w/GT35R, B&B Headers, RarlyL8 muffler, TurboKraft IC, Tial WG, tecGT based phased sequential EFI & ignition, Wevo shifter/coupler, ...
Old 10-13-2016, 04:28 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #26 (permalink)
 
Registered
 
Join Date: Jun 2014
Location: Denver, CO
Posts: 1,068
Garage
I picked up a complete set of lines for mine earlier this year from Len.. Just wanted to chime in as a happy customer

__________________
'79 930 turbo RoW - Oak Green Metallic - k27-7200 - Kokeln Intercooler - RarlyL8 headers/muffler - Leask WuR - Tial 46mm - Rebel racing bushings front/rear - ER Monoballs front/rear - ER adjustable spring plates - 29/23mm TBs - Wevo engine mounts - Rebel racing transmission mounts - Ruf speelines 17x9-10
'99 4Runner Sr5
Old 10-13-2016, 09:03 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #27 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 04:10 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2020 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.