924Board.org

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

I set the upper flywheel with the valve cover notch. Now I am trying to adjust the valves. haynes says to get the #1 cylinder to top dead center by turning the motor over via the oil pump bolt. But how am supposed to know when the number one cylinder is at top dead center? Is there a mark on the bolt corresponding with the oil pump itself? Any advice would be appreciated. Thanks

Paul · Posted: Tue May 18, 2004 9:05 am Post subject:

Just put the car in top gear, and push it until one of the lobes is pointing straight up and adjust it.

Repeat 7 times

Smoothie · Posted: Tue May 18, 2004 9:06 am Post subject:

You're over-thinking this and Haynes has it overcomplicated.
Just check clearances for the valves that have their cam lobes pointed up away from the tappets, then turn the engine to point the lobes away for the next ones you want to check, etc., etc.
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"..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

augidog · Joined: 03 Mar 2003 Posts: 1360 Location: New Jersey

Lobes up .

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1978 924 95 mile daily driver.
Audi TB/POR174M/High Flow Cat/2.25" exhaust
I knew that positive thinking thing wouldn't work.

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

Turning the engine over via the oil pump will not let me point some lobes up. and as the first lobe is just about up it locks up on me.

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

This post <click> will answer your original question about aligning #1 TDC with the camshaft. Make sure the cam gear is aligned with the pointer, and the TDC mark is in the the little window.

If you aren't able to turn the motor over by hand using the 24mm nut on the crankshaft, remove the spark plugs then try it again. If it still "locks up", then you've got somthing wrong, and setting the valve clearances are the least of your worries for the moment. You have to be able to rotate the crank in order to adjust the valves.
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'79 Eurospec 931

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

It isn't completely locked up. i can only go so far before it lockes up in either direction. there like a space where the everything moves freely. Taking the plugs out didn't make a difference, thanks though.

Smoothie · Posted: Thu May 20, 2004 8:16 am Post subject:

Joe - Which is this... an '80 924na or a 924 Turbo?
_________________
"..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

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

80' 924 turbo

gohim · Joined: 02 Nov 2002 Posts: 4459 Location: Rialto, CA

joe,

Have you been remembering to put the transmission in "Neutral" before you try to rotate to the engine?

Smoothie · Posted: Thu May 20, 2004 9:19 am Post subject:

If it has been in neutral and you're getting resistance, then there's the possibility that your timing belt isn't on right and your camshaft isn't oriented correctly with the crankshaft. If that's the case, then the resistance you're feeling is pistons meeting valves. There's more than one mark on most cam sprockets (aka- "upper flywheel"). Make sure the mark you're using is the one that sits between two teeth (at a valley between 2 teeth) as shown in CMXXXI's pic, - not the mark that's right on a tooth.

Also make sure that when the flywheels' tdc mark is visible in the bellhousings' window, that the notch on the front crankshaft pulley lines up with it's pointer on the oil pump - at the same time. This will verify that the flywheel was replaced in the correct orientation (in case it was ever removed in the past) - and that the flywheels' tdc mark is really tdc.
_________________
"..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

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

I know what mark you are talking about. but how exactly do you set the valves with the pistons? I figured this was the problem, all i have to go on is the haynes manual and they do not do a very good job.

Smoothie · Posted: Thu May 20, 2004 9:56 am Post subject:

You have to have #1 piston set at tdc. This is when you have the "Z1" mark on the flywheel visible in the bellhousings' timing window -and- you should at the same time see the front pulleys' notch line-up with the pointer on the oil pump. That's tdc for the crankshaft, but don't set it there yet...

Camshaft tdc is simply lining up the cam sprockets' mark (the one between two teeth) with the valve covers' pointer and viewed from behind.

Since this is an "interferance engine" you can't just set the crank at tdc then go and turn the cam to tdc because you could have valves hitting piston in the process, so... with the spark plugs removed, Start with the crankshaft set, oh say at least 15 or so degrees away from tdc or bdc (bottom dead center) (basically anywhere but tdc or bdc) - so you don't have a collision. -Then set the cam sprocket on its' mark, then rotate the crank back to tdc gently (if you find resistance, stop and try rotating the opposite way to find tdc - gently). When both the cam and crank are at their tdc marks, you put the belt on, rotate the tensioner wheel counter-clockwise to tension the belt, then tighten the bolt or nut on the tensioner.
_________________
"..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

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

Thanks a lot there smoothie.

Joes924Racer · Posted: Thu May 20, 2004 12:22 pm Post subject:

and if its done right with the plugs out yoube able to turn the motor over using a socket with a 1/2 drive prety easily. when the pointer on the valve cover ligns up with the mark on the back of the cam gear that should be tdc the lobes should be up after you adjust the first 2 valves intake
exhaust turn the motor again.
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1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.