chuckaroo

Hi Guys
I'm timing my 66 327/300. To set the initial advance, you have the idle adjusted to 500 rpms and disconnect the vacuum and plug. My question ...do you set the idle speed before or after you disconnect the vacuum? I checked Service Manual and many post....no answer. Thanks.

Gary's '66

Your idle should drop after you disconnect the advance so you'll need to increase it. Google "Lars Tuning Secrets". Lots of very good info there.

Gary

Godholio

I've never been able to get mine to idle smoothly under 800 rpm or so, same year/engine.

Frankie the Fink

An unmodified SBC 250/300 HP should idle fine a lot lower than 800 RPM. My SWC idle is intentionally high at 750 RPM so when I cut the A/C on it goes down to a nice, smooth 600 RPM (4 speed car). Of course age, vacuum leaks, timing variations, centrifugal advance coming on too soon, are all factors.

lars

When setting/checking initial timing, you have to do so with the rpm at a point lower than the start point of the centrifugal advance curve. Most centrifugal curves start adding advance at about 800 rpm, so you check the initial at an rpm a bit lower than that. If you can get it to idle at 500, that's fine, but may be a bit over-kill on the low rpm... It doesn't matter if you set the low idle before or after you yank the vacuum hose off, as long as the rpm you're checking the timing at is low enough to assure that the advance weights are fully retracted.

Lars

chuckaroo

Try again...Pecked out 2 emails to answer your replies but before I could send... Puff gone.

Thanks Lars and all replies.
Now at 3000 rpm all in is 30 deg recommended 36 deg. Should I adjust to 36 Deg? Would like it correct so how to fix? Car has hesitation above 4000 and accelerating. Wanted to adjust timing set up so I could feel I address any electrical gremlins. Bottom line the car runs rich and Holley has a high pitch whistle. Want rebuild but wanted to address any timing problem first. Thanks BTW initial set at 10deg.

MelWff

did you adjust the points dwell angle to 30 degrees before adjusting the timing? You should aim for a total of 36 with vacuum disconnected while setting it.

chuckaroo

Yes sir
Dwell dead on 30 degrees. I have an advance timing light and it will check volts, dwell, timing, rpm, maybe even barometric pressure and wind direction. How do I go about obtaining 36 deg? Up initial, change centrifugal advance springs? Is there a kit to handle this adjustment? Thanks for all your help I appreciate.
BTW I don't remember disconnecting the vacuum. Will that effect the final degree?? Apparently or you wouldn't mentioned lt. I'll try again. Thanks.

MelWff

You set the initial to, in your case 16, but than recheck it at 3K to insure you have a total of 36, you most definitely have to do this with the vacuum disconnected.

chuckaroo

Will do and check for 36. Will try later when I get a chance and let you know. Is this the usual way to get 36 deg just by adjusting the initial timing?? I will do this in the future. Sure appreciate your help. Thanks.

JohnZ

With base timing set at 10* and total timing showing only 30*, the distributor is supplying 20* of centrifugal. You can get to 36* total timing two ways - either add 6* to the initial (to 16* BTDC), which will add that 6* to the total (36*), or add 6* to the centrifugal by removing the limit bushing or lengthening the slot it moves in - that will get you 36* total while keeping initial at 10*. The 6* is purely an estimate - you'll have to check with a light to see exactly how much you gain by removing or changing the limit bushing.

You need to check for detonation in either case, but definitely if you crank the initial up from 10* to 16*.

If the Holley has a high-pitched whistle, you have a vacuum leak - usually that's a wrong baseplate-to-main body gasket and/or loose baseplate-to-main body screws.

chuckaroo

Sorry for the delay in a reply but when I went to apply some of your suggestions my advance timing light broke. I did set the initial timing to 8 deg. Will reply later. Thanks

chuckaroo

Hi Guys

I'm back again. I haven't done much with my timing since advanced light isn't working so I started to checking out my distributor. Now, I remember being able to turn the rotor a few degrees against some spring tension and then return. When I tried mine it didn't budge. When I checked the centrifugal weights they moved in and out with no resistance...totally free to move. The small springs were in place. I would guess the weights would move out when cranking to start....no centrifugal advance. What's up with that?? What parts would be needed to fix the advance mechanism?? Thanks.