fastduck

So sorry, but I can't find a post that said not to turn the cam gears a particular direction once at TDC even using a Bumpstick and 32vR. It might have been how to sneak up on the 1-4 setting if it's too advanced? - by changing them at 20 BTDC?
Wouldn't this all be easier to record just how far off I am at TDC, then rotate crank to 45 BTDC and adjust the cams gears that number of degrees?

Thanks, in despiration,

John - (not so) Fastduck
Tucson
'88 S4

MBMB

Doesn't the 32v'r have a notch for setting the cam timing at 45º?

fastduck

Yes it does, but everyone recommends that the 45 measurement is used only as a "rough-in" setting to safely get you close to then be able to check it (adjust?) it at 0 TDC.

Leon Speed

I don't get the issue your trying to solve. You can set timing at 45 degrees, then go to TDC and make final adjustments, together with setting the correct tension. At TDC if you loosen the clamp rings on 1-4 you need to hold the bumpstick tightly because the cam will try to rotate counter clock wise. Cam 5-8 will try to rotate clockwise.

PorKen

Crankshaft. Don't turn the crankshaft CCW.

Once loosened, cams can be turned CW or CCW.

(Not too many attempts w/o spinning the engine again, though. Adjusting back and forth changes the belt tension and the reading will be off.)

Leon Speed

Ken, a quick hijack: at TDC I accidentally let cam 1-4 rotate CCW way past the 32Vr, maybe twice as much. I caught it and didn't feel or hear an impact. Kind of freaked but since the pistons weren't moving I figured if any valve hit a piston, it wouldn't be bent. Do you know if a valve would hit if cam 1-4 rotated let´s say 20 degrees CCW?

the flyin' scotsman

Remeber the basics guys.
At 45 BTDC all 8 pistons are far enough away from the top of their respective strokes that the cams can be turned 360. The closer the crank is turned to TDC the cams will be opening some of the valves.

fastduck

An extreme thank you to all commentors; I'll be interested to read the reply to Aryan's last question - no it hasn't happened to me yet!
I had been mis-remembering one of the PK instructions in which it's mentioned sneaking up on timing using the crankshaft position before TDC. Again, Ken's handholding comment - crank ALWAYS clockwise, cams no problem.
I pulled everything and reset the cam gears to the middle of their adjustment range (PK32vR bolts in gear slots) and now I think that everything will be fine.

John

SeanR

Put it to TDC and adjust the cams. Yes the valves can touch but unless you are doing some serious cranking on it, no damage will happen.

the flyin' scotsman

Aryan.......the reason the cam falls back in that direction is because of valve spring pressure.

the cams turn to open the valves but they close by the springs so when the cam has nothing to keep it from self turning the valve spring forces the cam and the valves slam close not open and would not bend.

Remember that at TDC #1 and IIRC #6 pistons are at TDC, the other cylinders are on compression or exhaust or power.

Leon Speed

Right, that's was I was thinking/hoping.

I follow you, but maybe I'm not seeing it completely. When cams on 1-4 turn ccw at TDC the valves on cylinder 1 are closed since it's on the compression stroke. Valves on other cylinders will close as well since the spring pressures force the cam to turn. I am wondering though if all other valves are closed or if some are opened because turning ccw is the net result of springs working against each other. Don't know if I am making sense here. Anyway, since the pistons were not moving this might be an academic discussion damage-wise.

the flyin' scotsman

ok.....at TDC the #1 cyl valves are closed but others are open....and there'll be at least 2 (4 valves per cyl) and both intake and exhaust cams are tied by the chain.

I dont recall which valves would be open but the cams turn back CCW to a position where most of the valves are closed.