How to remove manifold link arms?

[TonyHayers]

I'm doing a port and polish on a second intake manifold that I bought. The link arms on this one don't look as good as the ones on my existing manifold so I'd like to swap them when I fit it, but I can't see how to remove the flap pivot arm so they can come out. It must be possible since someone (034 motorsport or JHM) sell aftermarket machined replacements.

Anyone done this?

[caldy]

Yup albeit a long time ago.

Knock through the 16 core plugs allowing access to the 16 screws holding the vanes to the shaft. Remove these and the vanes.

I think you then prise off the cap covering the end of the shaft and drift it out.

I sourced new shaft bearings and core plugs for re-fitting.

You gonna re-fit the vanes or leave them out? You already have a cold air feed and you may have removed the secondary air injection pump, in which case you don't need the vanes or the actuating arms as their presence will have been 'mapped-out'.

[TonyHayers]

Yup albeit a long time ago.

Knock through the 16 core plugs allowing access to the 16 screws holding the vanes to the shaft. Remove these and the vanes.

I think you then prise off the cap covering the end of the shaft and drift it out.

I sourced new shaft bearings and core plugs for re-fitting.

You gonna re-fit the vanes or leave them out? You already have a cold air feed and you may have removed the secondary air injection pump, in which case you don't need the vanes or the actuating arms as their presence will have been 'mapped-out'.

Hi caldy - sorry, should have said, I've removed the flaps already - managed to do it without removing core plugs by using a very low profile ratchet. I just can't see how to take the shaft out. Is it held in by friction or do the slotted ends screw out?

I'm not going to refit the flaps, but am thinking of leaving the shaft to rotate freely. Will be getting a remap once I've done the manifold prep and carbon clean.

[TonyHayers]

Just posting some photos of the ends of the shaft. One side has the slotted bit each end and the other side has one slotted end and some sort of cap (first picture).

[adsgreen]

slotted ends look like position sensor mounts - I'd be surprised if it was around there.
Doubt it would unscrew as the arms must be mounted somehow. I would expect turning it would break the arms.
What about pair of pliers on the slot and pulling?

[caldy]

I think if you gently tap on the opposite end to the actuating arm, the shaft should drift out.

[TonyHayers]

Cheers chaps, will give it a try tonight.

[adsgreen]

http://www.youtube.com/watch?v=xaghVWhqXHQ

[TonyHayers]

http://www.youtube.com/watch?v=xaghVWhqXHQ

Haha. I actually have a kilogram of thermite in my garage (long story). That might shift it.

[adsgreen]

http://www.youtube.com/watch?v=xaghVWhqXHQ

Haha. I actually have a kilogram of thermite in my garage (long story). That might shift it.

Try putting some on the bonnet of a car of somebody you don't like very much. The fireworks are fantastic

[TonyHayers]

hrm, gently tapping didn't work. Don't want to give it too much welly in case I damage bearings/seals :/

[billq]

There are black tab things that line the shaft up.
They pull straight out.
Circled in blue..

[TonyHayers]

billq - you utter hero!

For anyone else in future, pull the black plugs out and tap gently on the shaft towards the flap end.

[adsgreen]

pull the black plugs out and tap gently on the shaft towards the flap end.

<fnarr>

[TonyHayers]

pull the black plugs out and tap gently on the shaft towards the flap end.

<fnarr>

I was expecting somebody to comment on that ...

Bit of an update if anyone's interested. Porting is going well, can remove quite a bit of casting imperfections. Started with dremel, but by far the best tool I've found for doing the trumpets is a 50mm x 20mm abrasive flap wheel on my regular electric drill (cordless isn't fast enough). The 50mm wheel *just about* fits in the trumpet and does a really nice job of smoothing out. Because it's a good fit, you can get a nice even shape across all trumpets.

I'm not sure whether I'm going to attempt to grind out the "step" in the runners before the flap shaft. Seems to me that it nicely guides the incoming air over the potentially turbulent flap mechanism. I can see now why people lock the flap shaft, since that leaves it completely flat.

It looks quite awkward to do a really good job. Not sure whether to gamble this is only a spare manifold, but things are going well so far!