Special Washers

Superman · 03-02-2002, 09:40 AM

I cannot seem to locate my Performance Handbook but I hope to find it before I see your responses. Bruce said something about special washers to be used under case half fasteners (I think). He sais to test them, put them on a stud between two nuts and tighten them to see if they deform. He says not to use the oneds that are not the 'real McCoy.' Does anyone recall this and what is he talking about?

rcwaldo · 03-02-2002, 09:46 AM

He is speaking of the aluminium crush washers. Mostly the 8mm ones. They come in your gasket set. Some aftermarket suppliers use a softer grade of aluminum which crush too much.

Hope this helps..

Chris

Superman · 03-02-2002, 09:50 AM

Okay, so he's just talking about all those washers I am supposed to replace when I adjust my valves, etc?

marcesq · marcesq's Garage

I may be way off base here, but the washers that Superman is discribing are the special washers used on either side of the bolt and nut that hold the engine halves together. They are flat on the out side, and champored on inside.

In the valve adjust kits that come with everything, included are the aluminum washers and nylock nuts that are needed for the valve covers, as well as washers for the sump and oil tank plugs.

FWIW.

Formerly Steve Wilkinson · 03-02-2002, 11:00 AM

No, he's talking about the standard aluminum crush washers that are used in lots of places on the engine. By crushing, they act as seals.

Stephan

bjola · 03-02-2002, 11:55 AM

Stephan and rcwaldo are right Superman is talking about the crush washers. Don't waste time and money buy the original Porsche washer they will not fail.

Superman · 03-02-2002, 05:50 PM

Well, I still need to find my Performance Handbook, but I do remember Brice talking about this 'crush test' for washers, and I thought they were special washers. More special than valve cover washers. I notice that the nuts attaching the case halves on the outer perimiter of the case do have washers under them that are 'standard' looking as opposed to the strange conical ones that the main bearing studs use, with o-rings underneath.

So, I'm still not sure. I'll have to find my Performance Handbook. Where did you guys put it when you used it last?

pwd72s · 03-02-2002, 06:05 PM

Crush washers aren't just crush washers? For years now, I've used both aluminum and copper (?) crush washers on both oil drain plugs, and I've found both to work well. Is one type or material superior? I'm getting confused here. But that's not unusual...

Superman · 06:22 PM

See below.

Superman · 03-02-2002, 06:21 PM

Okay, I've located the Performance Handbook. Someone must have put it in the laundry room. I won't say who I think it was.

On page 124 of the Second Edition Bruce discusses the need to replace the aluminum crush washers as a matter of course, during a rebuild. He says they are not just dead-soft aluminum. Instead, they are a silicon-magnesium alloy. He says put a couple on a bolt and torque the nut to 15 lb-ft. If they distort, they are not the Real Deal.

I think this is important for bolting case halves together, but not for installing valve covers. Softer washers could work loose under nuts that hold the case halves together, resulting in aggravating, mysterious leaks. Again, I doubt this would make much difference under valve cover nuts.

bjola · 03-03-2002, 01:26 AM

I think the problem with the crush washer is that if you get washers with too soft aluminum they will increase in diameter (elongate) when you torque them dowm. So instead of staying as a perfect washer under the nut they will creep out and leave one side of the nut with no support under it. This will result in incorrect torque and possible leak. Could be case or valve cover.

So buy the original part here, they are inexpensive and they work.

Bjorn