How difficult to remove intake runner tubes?

[bkreigsr]

One of my intake tubes has the original finish worn off.
The other three are okay, but if this is easy enough, I'll repaint all four.
How difficult is it to remove them?
Can they be removed individually?

Car is a 912E, so picture an engine in backwards.
(Should make it easier, right?)

Thanks in advance
Bill K

[Dave at Pelican Parts]

Doesn't really make it much easier.

The tubes are held in by the big hoses that connect them to the plenum (the manifold), and bot three M8 (13mm wrench) nuts at the outer end that hold them onto the head. You'll also want to remove the injectors, which are each held on by one M6 (10mm wrench) nut.

You remove the two M6 nuts on the one side, slide back the metal retaining clips for the injectors, and slide the injectors out of the intake runner pipes. Then remove the three M8 nuts and washers. Pull the two pipes outward and wiggle them. It may take a little effort to get them lose from the head, and it should take effort to slide them free from the plenum.

Note: I am not sure if the 912E has other stuff attached to the runner pipes or that are in the way; you may have other stuff to remove before you start pulling the rest of the things out.

You should plan on replacing the fuel injector seals at the very least. Replacing the gaskets (plastic spacers) between the runners and the heads is probably a good idea too, as is replacing the fat vacuum hoses between the pipes and the plenum.

--DD

[bkreigsr]

Thanks Dave.

Not as easy as i thought - but still way more straight-forward than the six cylinder motors.

Do I need a special tool/pick to slide back the FI retaining clips?

Bill K

[Dave at Pelican Parts]

Nope, no special tool needed. There is a metal ring with a tab on one side. The mounting stud goes through a hole in the tab. Remove the nut and washer from the stud, and the ring just pulls off. Then the injector pulls out of the recess in the intake runner pipe.

--DD