85/86 metal oil filler neck part number(s)
05-24-2018, 09:04 PM
#1
Three Wheelin'
Thread Starter
85/86 metal oil filler neck part number(s)
referring to 1985 and 1986 metal oil filler necks:
can someone tell me if there is a difference between 928 107 303 1R and 928 107 303 5R?
early v. later version or different parts?? can seem to find in PET
can someone tell me if there is a difference between 928 107 303 1R and 928 107 303 5R?
early v. later version or different parts?? can seem to find in PET
05-25-2018, 12:50 AM
#2
Rennlist Member
The neck and baffle have been NLA for years as far as I know and have been superceded by the plastic neck.
I would just search for them on Ebay. That's where I got mine and I think a few are on there right now.
I would just search for them on Ebay. That's where I got mine and I think a few are on there right now.
05-25-2018, 05:34 PM
#5
If you buy a used one make sure you get the valve with it for the oil breather line. It often gets lost or thrown out with the old hose.
05-25-2018, 05:43 PM
#6
Three Wheelin'
Thread Starter
If you buy a used one make sure you get the valve with it for the oil breather line. It often gets lost or thrown out with the old hose
FWIW: the numbers that I provided are not part numbers at all; they are casting numbers. the correct part number for the 1985/86 metal filler tube
is 928 107 083 02 and since this is NLA, it supersedes to the later plastic version of 928 107 303 07.
05-25-2018, 11:07 PM
#7
what is this valve? not on my 1990 plastic one? is there a separate part number in PET?
FWIW: the numbers that I provided are not part numbers at all; they are casting numbers. the correct part number for the 1985/86 metal filler tube
is 928 107 083 02 and since this is NLA, it supersedes to the later plastic version of 928 107 303 07.
FWIW: the numbers that I provided are not part numbers at all; they are casting numbers. the correct part number for the 1985/86 metal filler tube
is 928 107 083 02 and since this is NLA, it supersedes to the later plastic version of 928 107 303 07.
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05-26-2018, 11:52 AM
#8
Three Wheelin'
Thread Starter
[QUOTEThe plastic neck has the valve built in, 85 to early 87 had the metal neck and a seperate valve that sits in one breather tube port. Many run without it as there is no solution if you loose it. ][/QUOTE]
-can the built in valve be removed from the plastic neck and retrofitted into the metal?
-or is there a part number for that valve? I don't see it in the PET
-which breather port does this valve reside in?
-can the built in valve be removed from the plastic neck and retrofitted into the metal?
-or is there a part number for that valve? I don't see it in the PET
-which breather port does this valve reside in?
05-26-2018, 01:00 PM
#9
most people change the hose, and throw it out WITH the valve in it still......
05-27-2018, 01:00 PM
#11
Nordschleife Master
No. The 928 doesn't use a PCV valve method, it uses a metered orifice method.
The hose directly from the oil filler neck to the tri-port plastic piece in the rubber MAF elbow is a safety feature for a situation in which the restricted orifice from the rear passenger side valve cover port freezes due to condensation water.
In my opinion, that hose that goes from the filler neck into the MAF boot elbow is a safety device only. It's for some major pressure problems in the crankcase or (amounting to the same thing) if there's water in the other hoses that have frozen and is blocking the paths. It's not supposed to be just a check valve, it needs to have a cracking pressure that is pretty high, that is, over 1.5 psi (90 millibar). If you've got 1.5 psi in the crankcase, then having that hose run directly into the intake is a lesser of the two evils. In normal operation, nothing is supposed to flow thru that circuit.
Here's what Porsche patent filing says about it:
In my opinion, any check valve with similar cracking pressure anywhere in that hose would work just as well.
You don't want to run that hose without a valve, though, because otherwise the engine ingests too much oil during braking-to-WOT sequences.
The hose directly from the oil filler neck to the tri-port plastic piece in the rubber MAF elbow is a safety feature for a situation in which the restricted orifice from the rear passenger side valve cover port freezes due to condensation water.
In my opinion, that hose that goes from the filler neck into the MAF boot elbow is a safety device only. It's for some major pressure problems in the crankcase or (amounting to the same thing) if there's water in the other hoses that have frozen and is blocking the paths. It's not supposed to be just a check valve, it needs to have a cracking pressure that is pretty high, that is, over 1.5 psi (90 millibar). If you've got 1.5 psi in the crankcase, then having that hose run directly into the intake is a lesser of the two evils. In normal operation, nothing is supposed to flow thru that circuit.
Here's what Porsche patent filing says about it:
When the main ventilation system 6 fails, for example, caused by icing (=closing of the throttle bore and/or of the outlet opening of the connecting piece), the excessive pressure in the cylinder block and crankcase 3 will rise because of lacking pressure balance and the safety ventilation system 7 will be actuated. In the case of the safety ventilation system 7, the crankcase gases, via an opening of the cylinder block and crankcase 3 that is not shown, will reach the oil filler neck 8. At 16, a safety valve is inserted into a connection of the oil filler neck 8 that opens at an excessive pressure of 80 to 100 mbar. When the safety valve is open, the crankcase gases, via a line 17, flow directly to the air guiding housing 15 (FIG. 2).
You don't want to run that hose without a valve, though, because otherwise the engine ingests too much oil during braking-to-WOT sequences.
05-31-2018, 04:11 PM
#12
Three Wheelin'
Thread Starter
The plastic neck has the valve built in, 85 to early 87 had the metal neck and a seperate valve that sits in one breather tube port. Many run without it as there is no solution if you loose it.
still available; I can't any reference in PET? anyone have a part number?
05-31-2018, 04:52 PM
#13
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06-01-2018, 12:01 AM
#14
Electron Wrangler
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The valve in the plastic one is not at all the same as the inline valve press fitted into the hose end. The plastic valve relies on the filler body. You probably need to investigate an inline valve with the right crack pressure, temp tolerance & chemical resistance - it could be a barbed inline fitting as long as it can flow enough volume
Alan
Alan
06-01-2018, 12:46 AM
#15
Former Vendor
Why, why, oh why?
The plastic filler neck has the proper oil deflector built into it to go with my extra baffle. It has the proper check valve built into it.
The plastic version "warps" way less than the metal filler neck....I have to surface those things to death to get them flat.....and the plastic one has metal inserts to keep it from being crushed where the hardware it.
All one needs to make a plastic filler neck not leak (forever) is a fine bead of Drei-Bond on top of a new O-ring.....which I include with my extra baffle (along with the O-ring.).
Why are you beating yourself to death trying to get a metal filler neck and the associated pieces?
The plastic filler neck has the proper oil deflector built into it to go with my extra baffle. It has the proper check valve built into it.
The plastic version "warps" way less than the metal filler neck....I have to surface those things to death to get them flat.....and the plastic one has metal inserts to keep it from being crushed where the hardware it.
All one needs to make a plastic filler neck not leak (forever) is a fine bead of Drei-Bond on top of a new O-ring.....which I include with my extra baffle (along with the O-ring.).
Why are you beating yourself to death trying to get a metal filler neck and the associated pieces?