12 x 16 steel vs. aluminium washers on cam box oil fittings

[hannu_911]

I was trying to locate aluminium 12 x 16 washers for the cam box oil line fittings from my Victor Reinz gasket set. I only found steel washers on that size and started to wonder why that might be.
I found some washers that were close in size and are aluminium but those are 900 123 116 30 (A 12 x 15.5).
Then I noticed that Porsche indeed says 900 123 005 00 for that washer. So it should be steel!?

Porsche seems to indicate on these 900 123 xxx yy series washer the material by the second last digit.
i.e.
900 123 005 00 would be steel
900 123 005 20 would be copper
900 123 005 30 would be aluminium


Earlier when I was cleaning the cam box I actually noticed deep grooves under those fittings but I just thought that they were just been over tightened by the previous engine builder some 20 years ago. There were no grooves under the blanks at the front of the cam boxes, those were probably not opened by the previous engine builder. So Porsche factory knew how to tighten them up properly but at some point the ones with oil lines had been over tightened.
And yes, those washers I took out from the engine are steel.

I also noticed that when I rebuild my SC some 17 years ago I did not use those steel washers from the Victor Reinz gasket set but used aluminium ones instead. The steel washers are still in the left over back. I probably used aluminium just because Wayne said so in his book. I think that I ended up using the aluminium 900 123 116 30 A 12 x 15.5 in my SC. And because I did not rebuild CIS at that time I did not notice that those 12 x 15.5 washers were missing from somewhere else.

Porsche must have a good reason to use steel washers.
I did search this forum but there is not much to be found I think.
This is was the best hit with a very nice table of washers and their material.
steel cam tower rings who is right
The explanation by 914/6 is that fine thread and aluminium base would be the key for Porsche to use steel washer.
But that does not explain why PET specifies this steel washer also for the banjo fitting. The explanation for that could be that Porsche did not want mix with two different types of washers at almost the same size at the engine assembly line.

Or is the 900 123 005 00 number just some oddity in numbering and that part is meant to be aluminium after all. And the Victor Reinz has just selected the stell with assumption that the 00 means steel? And the previous engine builder used probably the same Victor Reinz gasket set.

My current thinking is that I will use these steel 900 123 005 00 washers between the cam box and the fine thread intermediate piece and then aluminium 900 123 116 30 washer on the banjo fitting.

[gled49]

Yes, steel washer under base fitting, and ALU or copper at banjo with hollow bolt. From about the SC era that’s the way it was, earlier engines didn’t use the steel washer. The big advantage is, once the base fitting is tight, u can tighten and loosen the banjo without counter holding the base fitting, it stays put.

[Henry Schmidt]

We use copper for all three washers. No issues in 30+ years. Install the base fitting with blue LocTite to insure a snug fit.

[Zuffenwerker]

Interesting. Never thought about looking in the catalog for that. I’ve never seen anything but copper or aluminum washers there. Never considered steel because I assumed it would leak.

[porschedude996]

Originally Posted by Henry Schmidt

We use copper for all three washers. No issues in 30+ years. Install the base fitting with blue LocTite to insure a snug fit.

This is true, use a bit of lock-tite. Whenever you try to loosen the banjo bolt the fittings come out of the cam tower. I’ve used both copper and aluminum washers. I never noticed a difference in sealing performance.

[Richey]

These were steel on my SC and were leaking so I replaced them with aluminum , no leaks , but
gled 49 makes a good argument to use them .

[hannu_911]

Funny how PET suggest steel on some years and aluminium on others.


I used steel versions only under oil line restrictors, aluminium on all other places.

[gled49]

Use what u want, they do come in gasket sets. Sealed bag with magnet.

[Henry Schmidt]

Originally Posted by gled49

Use what u want, they do come in gasket sets. Sealed bag with magnet.

That gasket set also includes blue case through-bolt o-rings that should never be used with pre-964 cases. There are always options and compromises with generic gasket kits so be aware. Ask questions and be open to expert opinion.

[gled49]

That’s why the bag isn’t opened, the point is the steel rings come in factory gasket sets.