QUOTE(emerygt350 @ Mar 17 2022, 05:15 PM)
Interesting Wonkipop, I hadn't really considered building my own lines in the tunnel. I had forgotten about that pressure issue too. Just worried about reliability now. When you guys say you put it on the firewall, what do you mean? Where did you put it exactly? Filter too?
by firewall i mean in the original position for 74.
which is the cabin/engine wall area.
strictly speaking its mounted off the metal panel off the edge off the longitudinal.
jambed right up in that corner underneath to get it as far from radiant heat sources as factory could. think earlier cars than 74 had it mounted on rear wall of cabin, engine side.
i've gpt a standard old style plastic cube filter pre pump. (have a stash of those in a box i bought 30 years ago). clipping still into the clips in that area the factory fitted.
its fine because that line is still gravity feed (or weak suction take your pick) from the tank.
after the pump and up in the engine bay i have a full flow high pressure filter (larger metal cylinder type) and i mounted that off the bracket that the decel valve bolts to.
thats not standard and i did it for two reasons.
1) i probably got the last set of original bosch injectors i will ever find. though thanks to mr. p i know now the datsun and other ones i could get. but i wanted to protect those injectors.
2) modern pumps when they spit their internal guts can put it through the fuel lines.
interestingly having pulled apart two original three port pumps those pumps i believe would never blow their guts into the fuel system. the way they are built and engineered.
you would have to be really unlucky. probably why porsche and vw left off any kind of high pressure filter post pump.
post above by
@Rob-O brings up interesting point.
think possibly fuel lines on 75 on had different diams due to pressure as well.
but really don't know.
i imagine the ss line kits with whatever diams they are work just fine as folks seem to do them with pump up front and it all works.
i've always wondered how many pre 75 914s are out there as ticking time bombs with 80s front pump conversions but still have low pressure clear plastic fuel lines through cabin.
EDIT
making your own fuel lines is fun.
but you don't want to be on a cold garage floor trying to endlessly fit them trial and error.
i think it took me about 3 days.
but i had to take a lot of breaks, walk away and come back.
i also had a person assist me at crucial times when i was actually test fitting to guide the upper end through the upper end of tunnel.
you get all the curves and kinks right for the tunnel and when they fit well,
you pull them out and do the last set of tight and tricky bends out of firewall and into engine area.
thats the fun bit when you go back to do the final fit.
intense.
you need the car well up in the air and take the rhs rear wheel off.
and once they are in have about 15 beers to celebrate.
also i found it a good idea to protect with reflective insulation where they travel across rear of cabin.
when you drive the car and stop the magnesium fan shroud is a heat sink and gets real hot and radiates right at those metal lines.
the original plastic lines did not have that problem.
so all the vapor lock problems get intensified without proper attention to remedies.