Quick Timing Question....
 

Okay here is a quick question I have for the experts.

What would happen if you timed your 1.8 to 15 degrees BTDC instead of 7.5?

Would it run cooler?

Mine was timed to 15 (My Mistake) and when I corrected it to 7.5 it seems to run hotter and rougher. It ran fine before but after looking at it I see the mark (Notch) I thought was TDC was actually the 7.5 mark. It is 3.5 blades to the right of the big support on the fan. not 4.5 likt the TDC mark should be.

Thanks in advance,

I was always told that too much advance on aircooled's was an invitation to disaster,they would overheat rather quickly.

But since it runs better with the timing retarded, I'd doublecheck that the vacuum and mechanical advance mechanisms are working as designed, especially that your vacuum diaphram on the dizzy is working.

Group, when in doubt could he look for maximum advance at 3500 like the 1.7's and 2.0's do?

go to the tech article here at pelican by pete dubler. others certainly know more than me regarding this but i think what you want is total advance @3500 rpm. bumping avance at idle could be a reciepe for disaster.

I took a glance at the tech articles, and there's one for timing carbed cars at 32-33 degbtdc at 3500. Why can you go with more advance on carbed cars than injected, will the fi cars preignite sooner due to leaner mixture? just curious.

I have a sinking feeling that in my cars past it was rebuilt and the person who did it made the 7.5 BTDC mark the TDC mark since it was the only mark on the impellar. When I time it to 7.5 past that mark it runs perfect.

Is is possible to put the Dizzy in so this happens? Or maybe the Cam gear is installed one gear tooth off?

Too much advance is definately a recipe for disaster! I learned the hard way last summeron the track. Mine is a 1.7 big bore but the lesson is the same. I burned two of my 9.2:1 Mahle pistons with timing set a few degrees past the 27 degree factory setting. A very expensive DE event!

that is definitive answer to your question. you've been warned.

Yes, I lernt da hard way. Tweeking da wrong tings on a teener ain't no good!

There's only one key on the fan pulley, so it can't be put on wrong. I could be a pulley from a different car, though, with different marks. TDC is marked on the Flywheel as well, and you can view it through an opening at the top rear of the engine/front of the transmission, under the upright rear engine tin.

what's the nature of the irregular running? a change in timing of that nature should just be engine speed change, anything else might suggest another problem