Ignition timing, noob question.
 

:confused:hi, just wondering i set my timing gun to 5degrees advanced [stock spec.]and its lined up with engine housing. When i rev the engine pass 2k and up slowly the mark goes around 5 degrees below the main mark and holds steady all the way up the revs. At idle its fine . is this normal? or should i adjust when reving the engine pass 2k to line it up to mark? or in other words i guess put timing to advance 10 to even it out when reving pass 2k and up?1980 911sc 3.0litre

You might want to check the operation of the distributor advance mechanism and make sure everything is working freely. These things have a tendency to get rusted up.

If I understand your post correctly, the ignition only advances 5 degrees when you rev the engine? Sounds like your advance mechanism is gummed up. You should be getting way more than 5 degrees (more like 24 degrees) of timing from the mechanical advance, and another 10-ish degrees from vacuum advance if it's still hooked up.

Wellllll,..not really. :)

SC's have VERY lazy (late) timing curves and you'll not get full advance to around 6K. Run the engine to 6K (quickly) and see if the 30 deg mark lines up with the notch.

Do 1980 SCs have a 30 degree mark? My 79 does not. Maybe his is euro, or maybe I'm mistaken. Or maybe I'm blind.

J

I made a mark on mine, based on the distance of the 5 deg mark. I marked 20, 25, 30 deg.
David

make sure you check all timing advice with Lorenfb



:rolleyes:

Check out the link below; I'm guessing the most you are supposed to get is a 10 deg advance at 3000 rpm because you have a dual vacuum advance/retard.

Im pretty sure you should be getting total advance between 27-30 @ 6000 RPM and max 32 degrees advance. If its not advancing steadily through the RPMs, then its getting hung up which could mean you need to service as Milt said above, or your vacuum line might be cracked, possibly your distributor advance mechanism and springs are rusted or gummed up, it might just need a good cleaning.


http://forums.pelicanparts.com/911-engine-rebuilding-forum/196310-euro-sc-distributor-questions.html#post1654971

http://forums.pelicanparts.com/uploa...1102734079.jpg