Two timing marks?

1bad914 · 03-31-2003, 08:10 AM

I have two timing marks on my fan, one is a groove and is painted red, the other is a circle and has a little white mark. I went with the red one when I set up valve lash and geometry, but I'm not sure. My flywheel is lightened so I have nor mark on it. Don't you love it whe the PO's do this fun stuff, Someone needs to design an indexed/numbered fan, as in the Type I pully!

rockaria · rockaria's Garage

The red mark looks like 27 Degrees BTDC and the other mark looks like TDC. On my 1.8 I have one red notch at 7.5 BTDC wich I used to think was TDC, but I was corrected by my mechanic and now it runs much better. Luckily I had not done my valves yet...

I was told that on the 914 engine fan approx. 4.5 blades from the right of the big support was TDC, 3.5 blades is 7.5 degrees and that blade just to the right is 27 degrees. Just in case that helps.

Bleyseng · Bleyseng's Garage

As Chris said "the red mark is 27 BTDC and the white is TDC. Time the car at 3500rpms to the red mark, it might help your idle problems.
Geoff

maf 914 · 03-31-2003, 12:33 PM

Now is a good time with the fan exposed as in the picture to add some timing marks if you want to play around with the timing. You can measure the circumference of the fan with a tape or long piece of paper. Divide the circumference measurement by 360 degrees and you will get the distance between degrees as marked on the circumference. Use a triangular file or other cutting tool and add a few degrees marks on either side of the red mark. Leave the red mark red and paint the new ones another color.

Mike

Dave at Pelican Parts · Dave at Pelican Parts's Garage

Try checking the fan "0" against the notch in the flywheel. You might find a surprising bit of difference!

Evidently the fans aren't as exact as I'd always believed...

--DD

1bad914 · 03-31-2003, 04:25 PM

I reset the valve lash using the white mark. I also pitched the 911 adjusters and went back to stock, the valve geometry is spot on! I have a lightened flywheel Dave, it has no mark...oh well.

bander · 04-01-2003, 07:29 AM

I did exactly as Maf 914 discribed but first I found TDC and marked the fan 0 throught the fan housing. I used number punches to mark 10degree incriments, 27, 30 and 35.