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-   -   Wayn'es book shows TDC and reinstalling distributor with rotor unlike mine. He writes (http://forums.pelicanparts.com/porsche-911-technical-forum/461216-waynes-book-shows-tdc-reinstalling-distributor-rotor-unlike-mine-he-writes.html)

BReyes 03-05-2009 10:58 PM

Wayn'es book shows TDC and reinstalling distributor with rotor unlike mine. He writes
 
Wayn'es book shows TDC and reinstalling distributor with rotor unlike mine. He writes to align it to its 'tip'. Can't recall his exact words for this post. My question is do you align the small bosch rotor using its center (center to center: brass contact to the notch on the dizzy , or one tooth so the tip', aligns to it?

I know it is tdc, because I used a dental mirror and can see the piston with Z1 matched to the notch on the fan housing. I dont want backfiring on initial crank, and I heard it like backfire when I first cranked her over. motor did not start. Looking into getting the newly rebuilt carbs to squirt a little better, at this initial statrt up too, so, one issue or the other. Did I say the car did not start. I will not be back to the car for few days. Daytona 200 Friday and HSR at Sebring Sunday is my therapy, right. And of course Pelican.

Please post a pic.

I am going to crank it up next. I put it back in to the tip, like as it sweeps it is going to sweep across 1. Think I am on the correct tooth or one off now?

T77911S 03-06-2009 03:01 AM

the piston is always at the top when Z1 is at the top, its just that every other time it is not on the compression stroke. you have to check the intake valve, or, when you take the dizzy out, line the rotor up tip with the mark on the dizzy.

remove the left intake valve cover, turn the motor over until the intake valve starts to close, when Z1 comes around, that is compression TDC.

Zeke 03-06-2009 06:39 AM

I think he is asking whether you want the rotor to point to the notch after the dizzy is down in place or pointing to the notch as you start to push it down. The answer is the former, not the latter.

BReyes 03-06-2009 07:24 AM

I was at the center of the brass contact area of the bosch rotor to the notch of the dizzy, but cylinder no. 4 'squirter' did not squirt fuel into throat, and Gunnar style application of starting fluid gave one backfire i did not like. It was faint but low frequncy. Hope it was another neighbor and not coming from my car.

I had to stop working on it at that point. Next day Iremoved the dizzy again and moved it one tooth because of the word tip written in the book.

Now I am ordering VC gaskets to check the rocker, and install different valve covers while in there. By then I will have more thought to this and probably have to just spin it 180*. I was expecting to wait to remove the valves covers and do all four and after valve adjustment check.

BReyes 03-07-2009 06:49 AM

I am going to put it to the center of the rotor to the notch. I am going to rotate the dizzy 180*. I just removed the VC and have #1 rocker loose.

I will check thread monday.

Thanks again.

Gunter 03-07-2009 08:19 AM

If your #1 cylinder is at TDC with pulley showing Z1 and the intake valve rocker is loose, then you're at the compression stroke. That's good.
Distributor in hand, point the rotor to the notch and insert into the case.
Observe that the rotor will move off the notch position.
Notice which way it moved.
Remove the distributor and compensate one tooth.
Re-insert.
Now the rotor should point to the notch.

To determine compression stroke for #1 cylinder, I remove the intake VC for cylinder 1-3, remove spark plug for #1, insert a chopstick and carefully turn the engine by hand observing the stick.
When it is out (TDC) and the pulley shows Z1, I wiggle the intake rocker for #1.
If it's loose, it's compression stroke; if it's tight, it's exhaust stroke meaning a 360 deg turn of the crank is necessary.

911pcars 03-07-2009 10:58 AM

Removing the valve cover and replacing the gasket is a lot of work compared with just removing one spark plug. Use a compression gauge hose, the screw-in, detacheable from the gauge-type to determine TDC. The Sears or equivalent gauge at around $20 is fine (everyone needs a compression tester anyway).

Screw the tester hose into no. 1 cylinder, then rotate the engine clockwise until the Z1 mark is about 1/4 rev from the split in the crankcase. Place thumb or other body part over the hose end and continue to rotate the pulley. If the cylinder is on the compression stroke, you should feel air pressure escaping from the hose. If not, it's on the exhaust stroke. One more revolution and it will be on the compression stroke.

Different ways to rotate the engine:
1. Wrench on crank pulley
2. Wrench on fan pulley (push belt inward to remove slack and increase friction)
3. Shift to 5th gear, release parking brake, push car forward
4. Gearbox in neutral, jog engine with remote starter switch; (you have one in your engine compartment, right?)

Sherwood

T77911S 03-09-2009 04:19 AM

you will have to put the rotor a little off from the mark before you install, when the dizzy goes in, the rotor will want to turn as it goes in, you want the final position of the rotor to point to the mark AFTER it is installed. you will have to play with it and figure out where it has to be to get there.
go back to the beginning and verify the motor is at TDC compression by either of the methods above. foget about turning anything 180, just start all over.
i dont like to or think you need to stick anything into the motor, it can get wedged and break.
just watch the intake valve, after it closes, when Z1 comes around, you are correct.
compression gages works too, its just a pain, for me sometimes, to get the thing to screw in.


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