Mike O

I've been playing with my flywheel and this is what I think the clocking is



I'm in the process of installing a TECgt and it needs to know which tooth is under the sensor when the engine is at TDC. The flywheel is a Fidanza and it has a scribe line that lines up with the bellhousing index when the belt driven cam gear lines up with its TDC reference and the #1 piston is at TDC. My problem has been that turning the crankshaft smoothly enough to count the teeth accurately has been impossible. If you have a 968 flywheel laying around I'd appreciate a tooth count from #1 as shown above to the TDC ref scribe.

TIA!

Mike

PorscheDude1

here is a link to a picture
https://rennlist.com/forums/showthre...=60-2+flywheel

RajDatta

I have a spare unit sitting out. Send me a PM with your email address and let me know exactly what pictures you are looking for.
Raj

Mike O

Pictures are hard to work with for this. The tooth count from the -2 gap to the TDC scribe line is all that I need. I believe the answer is that the TDC mark is aligned with the the trailing edge of the 22nd tooth. As a tooth moves by the sensor, the leading or rising edge is first, then the flat top of the tooth followed by the trailing or falling edge and the bottom of the gap. If the printed info on the sketch is too small, save the sketch to your hard drive and zoom in with a viewer until you can see how I have numbered the teeth. Then just count

Raj, I believe you recently posted some flywheel pics showing the "OT" marking. That's really the only picture I'd like to see. That and the number of the tooth on either side of it would be perfect. PM on the way

Smokie - Alas, those pics don't show the "OT".

RajDatta

Mike, I sent you two high resolution picture to your email address. I think the pictures are good enough to get your answers. I have also posted these here in case anyone else has any question now or in the future.




I think you have your clocking flipped.
Regards.
Raj

Mike O

The pictures are perfect! Thanks!

I am flipped (off) many times. This time i think i'm in the clear. My sketch is looking at the opposite of the flywheel, the friction surface side, so rotation is CCW from that point of view.

Using Electromotive's terminology, the trailing edge of tooth 20 is under the centerline of the sensor when the engine is at TDC. My sketch is off by half a tooth. Now to figure out just why I made that error.

Thanks again!

RajDatta

My pleasure.
Raj

FRporscheman

Is that OT mark visible from the inspection hole on top of the bellhousing? I've never seen it.

RajDatta

Yes, that is the only place you would be able to see it. Its tough with all the other stuff in the area. That is why I try to use the 3 scribe marks and align from the bottom inspection hole.
They talk about it on 15-5 section of the factory manual.
Raj

FRporscheman

My flywheel doesn't have the 3 scribes. I looked through the little round hole (it still had the little rubber plug!), at all angles possible, and when the engine was near TDC, I would see 1 scribe. But that one scribe was not exactly at TDC - I found TDC using a dowel in spark plug hole 1. Now I have a dial indicator and I'll use that in the future.

Mike O

The Fidanza flywheel on my car only has a single scribe mark and I belive it is off TDC by half a tooth. That is what had me screwed up with the clocking.