Installing a 3.2 into a 73

[Shaun @ Tru6]

installed today new, final rear fuel lines from Pelican BoxsterGT. these are gorgeous custom fuel lines. also got the special high clearance oil lines in, pics to come soon. car now yard drives.

[crashr]

I have two questions. When doing the conversion why is it necessary to:

1) move the fuel filter to the front of the car from the rear? I have heard people say that the 3.2 fuel pump prefers to push the fuel instead of pulling it, but does it really make a difference? Does it affect fuel pressure, and if so in which way?

2) replacing the oil tank with a 3.2 tank. Other than the AAV and PCV vacuum circuit which most people cap off, why would this be required?

[Flieger]

Moving the fuel pump to the front gets it further from the engine heat (for less chance of vapor lock) and also allows for easier reinforcement of the rear anti-sway bar mounts.

[Shaun @ Tru6]

Good questions. Flieger has answered one and my understanding is that the later tank has better baffling inside than a 73 tank.

But my primary reason for duplicating factory conditions for the fuel pump and the oil tank is that they are...factory.

3.2 engine, oil, and fuel are all complex interrelated systems that work together. Makes troubleshooting easy and takes guesswork out of "why is this happening" as you have a factory system, whether it's in an 86 or a 73 body. Also makes for a more professional install, nothing goofy or half-assed like I've seen on way too many cars.

Any time I've deviated from factory, I've used professionally developed parts such as the fuel lines and the high clearance oil lines which are functionally indistinguishable from OEM.

[Shaun @ Tru6]

Took the car out yesterday for a quick lap, brakes felt terrible and had almost no brakes by the time I got back in. Took the car out of the garage today, big puddle of brake fluid where the center of the car was. the passenger side hard line from the block to the rubber line had rusted through. Naturally, it is one of the easiest lines to replace with the engine out and the hardest to install with the engine in. Had to remove the trans crossmember, lower it, and finally get a replacement line I had sitting on a shelf, installed.

Then I got the Steve Wong chip in. Then I went out again.

the car is fast, almost scary fast, and I don't even think I'm getting wide open throttle and know that I must be losing something to the 1 5/8 inch headers stepping down to the 1 1/2 inch 69E muffler. Still, it's fast, and fun. Big smile day. Now I've got about 10 hours of detail clean-up to do as well as lower the front end and get it aligned. Has been a great project, certainly worth all the time, effort and money.

Still have to post the custom high clearance oil lines too once the special S tube from the tank has gone through 1 or 2 more revisions.

[Gerry van]

Hi Shaun,
There's a fair chance you already have checked this but how does your air filter housing look on the intake side, there is a hose bracket that mounts off the back of it and over time cracks your housing,as l'm new to 911's just luckly found mine with 6k on a fresh engine.And lucky for me it had just started to crack.Good luck sounds like you got it sorted.Cheers Gerry

[Shaun @ Tru6]

hi Gerry,

Good advice for all to check this out. My housing is OK, it's all the hoses that will get replaced this winter. I don't have any leaks, but virtually every single rubber hose on the motor is on borrowed time.

[BK911]

Originally Posted by Shaun 84 Targa

Took the car out yesterday for a quick lap, brakes felt terrible and had almost no brakes by the time I got back in. Took the car out of the garage today, big puddle of brake fluid where the center of the car was. the passenger side hard line from the block to the rubber line had rusted through. ....

the car is fast, almost scary fast.....

That could have been very ugly.
Let this be a lesson to all the kiddies out there.
The STOP pedal is more important than the GO pedal.

Glad all is well.

[jm993rs]

I search and I would make !!!!

[JeremyD]

Originally Posted by Shaun 84 Targa

a little more progress.

Front and Rear factory metal lines running through the center tunnel flared with fittings.

Hey Shaun - if you don't mind - can you share some details on these fuel lines??

I'm looking to do the same in my car - Sizes of lines? Did you flare them and with what? Thanks in advance - love the progress.

[Shaun @ Tru6]

Originally Posted by JeremyD

Hey Shaun - if you don't mind - can you share some details on these fuel lines??

I'm looking to do the same in my car - Sizes of lines? Did you flare them and with what? Thanks in advance - love the progress.

Hi Jeremy,

Sure. My car is a 73T that once had CIS with the metal fuel lines through the center tunnel. Some time in it's life, a mighty 69 2.0T motor was installed. Whoever did the job simply cut off the fittings and flares on the tunnel fuel lines and added rubber fuel line and standard clamps, which was fine for the 3 psi.

Working with member BoxsterGT, I used a standard metric flaring tool like the one below, simply clamping each line in the block and then flaring it with the tool and pointy tap head. I guessed on the depth of tube needed to give a nice flare and got lucky. Important to slide the new fitting over the tube before flaring. Note that I made just a single flare, not a double as the tool allows with the adapters.

Len supplied the correct fittings to match to his custom made lines. the black ones are just for testing, he made beautiful braided ones for final.

My car came with 10mm feed and 8mm return lines as stock.

For your 3.6, I'm guessing you may want to go this route creating your own center tunnel lines out of a stainless tubing from McMaster Carr, just in 11mm or whatever diameter is appropriate for a thirsty 3.6, installing and flaring. I'd flare the front end by the way, then install, then flare the rear. it's tight back there so leave enough space for the fitting, the tool, and working space. if you have just a bare tub, you could install and flare both ends in the car I think. I'd put some rubber fuel line over the stainless here and there just so it doesn't clang around too much. Then you could just zip tie it to other stuff in the tunnel and not worry about sharp, factory tabs.

Give BoxsterGT a PM if you have any questions on fittings and custom fuel line, he can make some beautiful stuff for you, oil as well.

hope this helps.

S

[JeremyD]

Thank you - appreciate it - and know Len -as I sold him the 2.7 to make room for the 3.6...

[Shaun @ Tru6]

Good deal!