924Board.org

JjyKs · Joined: 05 Oct 2015 Posts: 114 Location: Finland

I put the head back to the car today, and when i started adjusting valve lashes everything went well, except for this one tappet.

My head was machined couple months ago. I'm 99% sure that i didn't mix the tappets witch each other. Is this machine shops fault and what are my options? Is this ok, or should i do something about it?

jason c · Joined: 13 Jan 2014 Posts: 1018 Location: Nwi

That looks to be right at the limit. You should verify that the screw is fully threaded into the tappet, not just catching by a couple threads. If its fully threaded & as long as its not sticking out it should be OK. However, you should remove it and find a scew with at least one less line so you'll have adjustment. The clearances should be checked hot & things will change with heat & wear.

Its normal to need different screws after head/valve work. As the valves & seats are ground, the valve moves up in the head, effectively lengthening the stem. This makes less clearance between the stem & cam which requires a smaller screw.

Fifty50Plus · Posted: Wed Mar 30, 2016 1:41 am Post subject:

I am in the process of adjusting lifters on a new cam/engine combo and that is too far out in my opinion. The far end of the screw in your photo is not in the threaded portion of the lifter. At best, barely one thread. You should replace it with a screw one mark lower (if it has 3 slashes on the end, replace it with one that has 2 slashes).
_________________
1979 924 NA race car H-Prod SCCA
1982 924 NA race car - Sold
1981 924 Turbo sold
1982 924 Turbo sold
1972 911 E race car - traded for Cayenne Diesel
1975 914 1.8 Building for H-Prod SCCA

JjyKs · Joined: 05 Oct 2015 Posts: 114 Location: Finland

Where can i find those screws?

Porsche dealer? Or are these some generic ones used in some VAG car as well?

fiat22turbo · Joined: 18 Jan 2006 Posts: 4040 Location: Portland, OR

They are VAG parts.

From the 924.org link above:

http://www.924.org/parts/parts.htm

different notches for different sizes, see the maintenance manual for application. 1 notch is thinnest, 4 thickest.

046 109453 C - 0 Notch

046 109453 D - 1 Notch

046 109453 E - 2 Notch

046 109453 F - 3 Notch

046 1094533 - 4 Notch
_________________
Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

Thought they were nla
_________________
Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

fiat22turbo · Joined: 18 Jan 2006 Posts: 4040 Location: Portland, OR

Wouldn't doubt it.
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Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

JjyKs · Joined: 05 Oct 2015 Posts: 114 Location: Finland

Thanks guys, I found couple shops which seem to still have them in stock (quite pricey considering that it's just a screw, 27€ but if i just couple of them it's not that bad) . Gonna adjust the 3 tappets i still have unadjusted and check if one of them has this same problem. After that i'll order the amount needed.

Another thing i was thinking was grinding down the current screw like 0.15mm or something like that.

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

You need screws with MORE not FEWER hashes on the end. And yes, they are NLA from Porsche, so the only option is finding new old stock or salvaged pieces.
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erstwhile owner of just about every 924 variant ever made

JjyKs · Joined: 05 Oct 2015 Posts: 114 Location: Finland

I had 1 more screw which got quite far out. I ended up carefully grinding both screws down by 0.2mm. However they were still on the treads on the both sides, and even had 2 turns more before they would've touched the wall so they should've been safe to use. Now they're 4 more turns in so that's good.

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

Are you saying you ground the flat? Rolling the dice... that is a hardened surface that takes a lot of abuse. Keep an ear on it.
_________________
Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

Fifty50Plus · Posted: Thu Apr 07, 2016 12:05 pm Post subject:

What Rasta said.
_________________
1979 924 NA race car H-Prod SCCA
1982 924 NA race car - Sold
1981 924 Turbo sold
1982 924 Turbo sold
1972 911 E race car - traded for Cayenne Diesel
1975 914 1.8 Building for H-Prod SCCA

JjyKs · Joined: 05 Oct 2015 Posts: 114 Location: Finland

Hmm, thanks for the warnings. I ground the flat part of the screws, not the tappet itself if it sounded like that. Gotta check them again after a while of driving.

Shouldn't the whole screw be hardened anyways? I used a flat piece of glass and like 3 arcs of fine sandpaper and measured every side of the screw multiple times during the sanding to ground it down symmetrically (it was so hard material that it took like 20 minutes per screw with 600 grid paper. Could this cause some damage to the hardened surface or should it be safe to assume that it's just as hard 0.2mm inside the screw as well?

The shops i found didn't ship to Finland so i'll keep an eye and ear on these two and if it seems like they're wearing down faster than they sould i'll just get the solid tappets with shim plates.