As mentioned elsewhere in this site, we do not adjust the timing ever to meet idle needs. The critical timing is at the upper end 28*@ 3,200-3,400 rpm. As distributors wear, the range of movement increases, so we take from the idle side. The BobD engine, for example, is now down at 2* BTDC at idle. I can easily increase the idle airflow to nail my 950 rpm idle speed, so I don't care about less advance at idle. You care. You have to care, with that camshaft. BUT, do NOT increase timing at upper end to compensate. If you can narrow the advance range, great, 10* to 12*BTDC at idle increasing to only 28* would be good for that camshaft set up.Ronin10 wrote:Haven't had a chance to straighten out my numbers yet (busy weekend), but did have the opportunity to play with different spring combinations in my 205P distributor, trying to make sure I have a centrifugal advance curve that makes sense. I never achieved spec (7.5 deg @ idle, 8-13 deg @ 1,600 and 20.5 - 24.5 deg @ 3,400 rpm - as given by OldVolksHome), but here's what my curve looks like: 8 deg @ idle; 8 deg @ 1,000 RPM; 16 deg @ 1,600; 18 deg @ 2,000; 20 deg @ 2,500; 24 deg @ 3,000; and 33 deg @ 3,400 RPM.
EDIT: I also received my shipment from German Supply so I removed my EGR and used the block off plate and swapped in the new brake booster tee. Morning drive in was pretty uneven. When the engine pulled smoothly it was really strong, but frequently it was interrupted with misfires either out the tailpipe or simple gaps in then engine pull. Will double check my valves as soon as I'm able.
Colin
(ask Air-Cooled.net if they have a SVDA with that artificially narrowed range)