Mike Simard

Don't bring me into your issues and imply I'm responsible for something happening to you. I've never said anything to anyone about you beyond what are in public postings here. I have no problem with you other than messageboard etiquite and we've both said our piece.
I have no idea why your post count is suddenly so low but it is frankly disturbing. Please leave me out of it.

BC

So unless we have drained the tappet, we cannot find out its internal condition by pressing on the button - is my understanding correct?

I have 32 S4 tappets that have been in a box for...oh, lets call it four years. I need to use them now, unless something happens where I buy new ones, but I dread a lower quality item.

Should I polish them, and then make sure they are filled with oil before assembly?

Mike Simard

Brendan, I did mention how the plunger feels with the oil drained but I honestly don't know what to tell from that. Maybe it takes a proper bleed down test under pressure, I don't know. I have put oil filled ones in an arbor press and it is a good way to get a feel for their function but we need someone more knowlegable to chime in.

BTW, there are some good cutaway drawings on the INA website. It might take some work but an enterprising soul could find them I could post the ones on my work computer tommorow if anyones would like.

Kevin Johnson

Erkka seemed to be saying that some tappets had springs present that were not working properly versus springs being absent. For the former situation it is a guess that the spring is compressed in place or otherwise stuck by deposits.

The Suzuki tappets had limited travel but the springs still worked to return the plunger when the tappet was emersed in oil or not.

Dave's tappets appear very clean and deposit-free which is interesting. I would open one up at least to know what components are present.

As to whether the lack of the main spring is a problem -- hard to say. Did Porsche add to or change the galley system with an anti-drainback valve? Was this an experiment by a previous owner? Are these actual Porsche lifters or ? If the lifters clattered every time it was started then I would be concerned.

As for polishing -- be careful. Wet sand with ultra-fine Crocus cloth at most?

Every manual I have ever read says to fill/prime hydraulic lifters with oil when you install them.

jon928se

Do you mean the anti-drainback valve in each head that is in the oil feed into the head ?

If so and perhaps relevant to the clattery lifter element of this thread, the O ring that seals the top part of the anti-drainback valve chamber off from the "cam box" is in my experience about as hard as concrete and as good at sealing as concrete would be on a 20 year old 928 engine.

The leaking O ring allows oil from the cams/lifters side of the anti-drainback valve to leak out but only into the "cam box" so no external leak is apparent. This causes reduced oil pressure to cams and lifter when the engine is running and when not running allows any pressurised oil in the head to seep out and rapidly loose pressure. If the lifter valving is not perfect this help the lifters to also loose oil resulting in clattery lifters.

Re filling lifters with oil on installation this is advisable but if you use oil under any pressure on a perfect lifter it is sometimes possible to over extend the lifter resulting in a lifter that is too big to re-install - dunno if this applies to 928 lifters but I've BTDT on GM engines.

BC

Crocus cloth? Is that like a **** rag?

Kevin Johnson

Yes, that is the valve that I was thinking about. Very good info on the seals. On some other engines these valves sometimes drop out of place when the head is pulled and this goes unnoticed.

David L. Lutz

I have checked the "oil check valve" in the heads and found them to be very sealed and clean. I don't think this is a source or cause of my tapping.

I will revisit the lifters based on discussion here in this thread and report back.

David L. Lutz

Mike,

Is this the INA page you are refering to?


http://www.ina.de/mediaDB/rel%20PubL...rnet/ivt_de_gb

This tappet does have the 2 springs Erkki was talking about. And it sounds to me after reading that the plunger spring is important as it adjust the clearence in the adjustment phase!

There seems to me that there is much more to the tappet operation that I first thought if this is the same design that we have.

Even though my engine looks super clean, it would appear that even the smallest amount of debris would affect the tappets operation!

Mike Simard

That's a good find!
Here's what I had:

Vilhuer

There is drawing of 32V lifter internals in '85 MY yearly changes document which shows similar two spring setup as is shown in INA document. Also some S4 brochures have similar pics IIRR.

After checking lifters from several 32V engines it seems to me that lack of spring action could be result of lifter piston being compressed too long. These springs can be totally dead and have resistance free piston travel. Some of these lifters came out of fully working engine which didn't display any serious symptoms which would make one think lifters are bad. Obviously second spring was put in for specific purpose of lifting lifter body up against valve lobe but it seems lifter can work ok without it. Valve spring must push piston up enough for lifter to get fresh oil feed into it during base lobe or these dead spring lifters wouldn't ever get oil in them and they would remain noisy.

David L. Lutz

Could someone tell me the best way to take one of these lifters apart?

I have cleaned thru the inlet hole with WD-40 and still no spring to the button at all.

David L. Lutz

Erkka,

Are you saying that given all else is correct if my valve spring isn't correct (height wise) this could be a source for tappet noise?

I am by no means capable of redoing my heads and I am sending them out for the valves to be redone. Should I give some special instructions here?

Kevin Johnson

I don't know if it is the best way but I put on a pair of thick leather gloves and grabbed the inner plunger with some small pliers and pulled them apart. There is a circlip sort of retaining wire.

I just sliced one of the Suzuki lifters in half and took a pic for you. It does not have the same extent of labyrinth for the oil but perhaps Erkka can compare it to the 1985 drawings. The Suzuki G10 engine was developed in the 1980s. The wedge head with bucket tappets in the later 1980s.

Edit:

Here are the pictures

Bill Ball

This may help as well.

http://www.nuvision.ndo.co.uk/tappets.htm