924Board.org

joe · Joined: 23 Apr 2004 Posts: 45 Location: Albuquerque

Alright, I am all ready to finish her up. Just put the exhaust manifold on (with the head in)and am ready to adjust the valves. With the first intake lobe pointing straight up I proceeded to adjust. With the guage at .004". After going through it a few times I am unable to get it to fit.

my77porsche · Joined: 09 Jun 2004 Posts: 63 Location: Stonington, CT

that sucks
_________________
looking for a great one......

1982Porsche924 · Joined: 14 Nov 2002 Posts: 679 Location: Cupertino, CA

I think Porsche offered multiple lifter adjustment screws, so that if adjustments was past the point of one screw, you could pick up another one from the dealer. I suggest going down to the dealership and having them find out for you. Not very hard to replace the screw, just take off the cam, take the lifter out, and change the screw.

Here are the different part numbers, not sure which ones allow more adjustability, and in what manner, but they should help somewhat:

046 109 453 C
046 109 453 D
046 109 453 E
046 109 453 F
046 109 453 G
_________________
1979 Porsche 924 "S"
Engine: Euro pistons, Light Flywheel, Weber TB, Bursch Header, Cam Wheel
Suspension: Front coil-overs, adj sways, Solid bush. Thicker tors. bars, 5-bolt, BBS rims
Body: Fiberglass widebody kit, 931 Nose

emoore924 · Joined: 13 Apr 2004 Posts: 2822

Problem is...

...to replace the screw you need to remove the cam. Not that hard if you're careful and follow the haynes or something, but not possible to change the screw otherwise so far as I can remember 'cause you have to take the follower out w/out the pressure on the spring...(if there is another way, please post, I'd like to know about it...)

BTW, it would be very unusual to have to replace a screw without changing the valve geometry, like changing the cam or having the head off and planing it, changing the deck height and therefore having a reason for changing the screw -- unusual unless you have something else going on like a bent valve or a cam lobe failure (cam lobe failure would allow MORE clearance, not less, so probably not your situation.).

Also, be sure you're using the .004 for the intake, follow the runner into the valve to be sure -- s/b .004 does fit, .005 does not for intake; .015 does fit, .016 does not for exhaust. All on a dead cold engine of course. For exhaust, better too loose than too tight, so if you're in a situation where the .016 won't fit and .017 or .018 will, that's ok, better too loose than too tight, especially on exhaust (more time for the valve to contact the head and transfer heat.)

joe · Joined: 23 Apr 2004 Posts: 45 Location: Albuquerque

Are the tappets different for exhaust and intake? Because there is a slight chance that I messed up the order and put in the wrong tappets. Could this be the culprit of my problem?

Smoothie · Posted: Mon Jun 14, 2004 1:42 pm Post subject:

That could easily account for your problem. The intake and exhaust tappets may all be the same size, but they're supposed to go back in their original bores on reassembly. There are several reasons for that. It looks like you found one of them.

_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

emoore924 · Joined: 13 Apr 2004 Posts: 2822

Mixing up the followers will do it...

I would take some time to make a few notes before you disassemble, and you will have to disassemble. BTW, this all assumes you have a Haynes manual, the right tools and some mechanical ability. Not a hard job for the shadetree mechanic but if you have no experience, you might want to find a bud who does before commencing.

Get a good light and one of those "mirrors on a stick". You want to spin the followers around in the bore (two fingers reaching around the cam will do it) so you can shine the light in the little hole on the side and see the marks on the end of the adjusting screw with the light and the mirror. They'll have anything from no little slash marks to up to 4 little slash marks. Some early ones might have paint dots in different colors. I think Haynes has the decode table.

Here's what you do.

1) Write this on a piece of paper: I E I E I E I E. That's Intake, Exhaust, Intake, Exhaust..., follow the runner to the head to figure out which is which.
2) Starting at the front of the motor, under each I or E, put a Y if you can get the follower adjusted in spec, or put a T or an L if you can't, either too tight or too loose -- BTW check the adjusting screw to be sure you're not screwing it in TOO FAR or NOT ENOUGH!! (the factory adjusting tool won't let you do this but most of those little allen wrenches will...) Also, be sure the screw has "clicked" into place and before you check clearance, and you've turned the cam once each time you've made an adjustment.
3) Use the light and mirror to identify the adjuster screw in each follower -- write down the number of marks for each follower beneath the Y, T or L.
4) If you can't get one or more valves into adjustment, remove cam.
5) Now here comes the hard part --- you'll have to identify the "optimal" orientation for all 8 followers and screws based on the notes you took above. CHECK ME ON THIS but I recall that more marks = thinner screws. So if you have an adjustment that is too loose with a #3 or #4 screw, look for an adjustment that is too tight with a #1 or #2 screw. Make note of those two buckets and screws and move on. Leave the Y's alone if you can. BTW, since we're assuming you misordered the followers, you should not remove the screw and put it in another follower to get things to work -- swap followers together with their screws, not screws alone. The goal is to get the followers and their accompanying screws back to where they were.
6) Based on your notes from above, swap buckets to get the "best" fit. Most likely it will be in pairs (think about it...

7) Put the cam back in and check your results. I'd probably just put the caps on and check clearances before I put the dizzy back in, the belt on and re-timed the motor. Don't forget to re-time the motor. Don't mix up the cam caps either!!

If that doesn't work, a piece of your story is missing or something else is going on.

FWIW, these screws are like hen's teeth and people don't like to sell them separately from the head or followers. Nevertheless, if you find only one bucket is out, call a junkyard and you might find someone with a drawerful someplace.

Paul · Posted: Tue Jun 15, 2004 7:40 am Post subject:

Did you have the valve springs off?

If so, did you seat the keepers once you reinstalled the springs, by hitting the top of the valve stems with a brass hammer?

CMXXXI · Joined: 05 Nov 2002 Posts: 1939 Location: Vicksburg, MS

The higher the number of slashes, the thicker the adjusting screw. If you can't get adequate clearance on a "no notch" adjuster, you'll have to grind it down ever so slightly. If you still have too much clearance on a "four notch" adjuster, you'r SOL.

emoore924 · Joined: 13 Apr 2004 Posts: 2822

Couldn't remember off the top of my head whether more marks = thicker or thinner hence the "check me" comment. 'preciate the clarification. As for the cold engine thing, the clearances given were for a cold engine because I assumed this is the first check coming off an apparent rebuild and therefore the engine would be cold. You're right, you do want to readjust after the motor is warm but I don't think they're there yet. In any case, the idea was to get the right buckets back in the right holes and I think the procedure probably works for that.

joe · Joined: 23 Apr 2004 Posts: 45 Location: Albuquerque

Ok, I got everything in it's place, and I am sure. Which leads to something else. I am unable to adjust the #1 and #3 exhaust valves. And those cylinders had some welding done because of pitting next to the valves. However, I can't remember where exactly it was done. So, could this be just a coincidence? Or the cause of my problem?

Thanks

Joes924Racer · Posted: Sun Jun 20, 2004 8:19 am Post subject:

Why cant you are they to loose, you most likely
have the adjusters mixed up still. Man times like these Im
thanking my lucky stars I have 3 good na heads 2 are the early
ones and tha other is older an 81. Had some welding done huh.
_________________
1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.

joe · Joined: 23 Apr 2004 Posts: 45 Location: Albuquerque

Yeah, your probably right. You know I wish there was some way I could know the thickness of each adjuster screw needed for each valve. Or maybe the machine shop screwed it up when they were doing the valve job. By the way, it's too tight, not too loose.

Joes924Racer · Posted: Sun Jun 20, 2004 4:03 pm Post subject:

Your missen something.. when you adjust the adjuster it gets hard to turn then loosens up thats the way it should be ..maybe you just have to look for a couple of the thinner adjuster. I dont have my book handy so I coudnt
tell you if more notches is thicker or what ...though seems you need to juggle the adjusters a little more to get it right... whatever you do dont drive it all messed up.
_________________
1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.