ErnestSw

When I sent my intake in for powder coating I did not plug the top or bottom holes for the flappy valve shaft. The holes were coated at least part way down and I had to ream them out to get the flappy shaft to turn. The flappy now turns very freely and when I put a vacuum tester (my mouth) on the actuator the whole system works perfectly.
I'm still pretty sure the needle bearings are trashed and that most of them don't turn.
Any suggestions, predictions, observations? (Other than that I'm a dumb s--t)

Jay Wellwood

When I refinshed my Intake I had questions about lubrication requirements, as these bearings are not mentioned anywhere.

The bearings can be replaced - but I don't know the part number off the top of my head. Maybe someone else knows?

For lubrication, I ended up using a dab of anti-sieze material (nickel based - trade name N-5000). No problems to report to date.

hth-

ErnestSw

Are they supposed to turn like real bearings?

Dave H.

only 90º and back...

mine got filled with glass bead when i blasted my intake. i just put a rag with some grease over the end of a 1/4 drive extension and shoved it into the bearing and twisted. kept repeating and working the glass out. then packed the bearings with grease. smooth...

Steve J.

Mine had the holes plugged during prep and powder coating. Afterwards, I used brake-kleen solvent and compressed air to get all the needles clean and dry and moving freely. Then I packed the bearings with grease using a toothpick.
<img src="http://www.flash.net/~ego/flpybrg3.jpg" alt=" - " />

ErnestSw

Hey Steve,
No fair planning ahead!!

Steve J.

Ernest - Sounds like you got yours working OK if the flappy actuates freely with your "vacuum tester". It will probably be fine. My understanding is that the bearings are not available as a Porsche replacement part, but some have had good luck matching them at the local bearing supply house.

ErnestSw

The flappy seems to work fine. I'm going to take the cam covers back Monday. I'll probably tackle the switchover next weekend.

Earl Gillstrom

This came out of my archives from rennlist:

Subject: Flappy Bearings BTDT
From: "Ralph S. Smith" &lt;rssmith@easystreet.com&gt;
Date: Tue, 19 Feb 2002 23:11:57 -0800
X-Message-Number: 5

Finally something I can contribute, just a moment to thank the collective
wisdom and especially the core experts for many little bits of knowledge
over the years.

OK, flappy bearings are supposed to be INA F-957762, but HK10 10 bearings
fit perfectly at about $3.00 per bearing. Now the caveats. The Porsche
part has a seal incoporated into the bearing, the ones I used don't. There
is a need for a seal of couase since this is the intake manifold. BUT,
vacuum leakage would be pretty minor since the shaft clearance is pretty
small and on the top end the cap completely seals the hole anyway.

A better solution than the HK10 10 bearing might be the HK10 12RS (rubber
seal) which has a seal and is 12 mm thick as is the original. Unfortunately
the RS was not available from the local suppliers, the story I got was that
it was something that was not in high volume so they built them once in a
while, probably when a mega order came in, but in between builds you were
just SOL.

Add a 10x2 O ring behind the HK10 10 and viola we have a seal again. The O
ring probably is fine in Buta alhough I was trying to get Nitril, I can't
actually remember what I put in I think Buta. The seals go in first then
the bearing, the retention lip for the bearing in on the interior side of
the intake manifold and the bearings press in from the outside. Be careful
to only press the bearings into the flush level. In other words the O ring
should be touching the lip and the bearing, but you don't want the bearing
crushing the O ring.

I can't tell you about the long term reliability for sure, but I have been
running this arrangement since February 2001 with no apparent problems. I
was most worried about too much friction with the O ring instead of the
seal, but after a little hand testing and then observation of the vacuum
actuator at startup I am pretty sure that the O ring does not inhibit the
flappy motion. I would guess that any leakage would show up as idle
problems. I was suspecting leakage a while back and did the test of
preasurizing the intake discribed in the manual and found no leakage.

Well, good luck, if someone else tries it, let us know how it goes, also let
us know if the RS is available this year.
RSS

&gt;Where did your mechanic get the replacement flappy bearings?

I got mine from Motion Industries (www.motionindustries.com), but you
should be able to get them from any number of bearing suppliers. The part
number you want is HK 1012 RS. Bearings like that are made by several
manufacturers including INA, NTN, and others. They all use the same part
number.

ErnestSw

Thanks Earl

Mattman928

Now for a dumb question! What does the flappy valve do?

ErnestSw

Why----it flaps----open to change the intake configuration under high acceleration loads.