That may very well be; I don't know how much advance the centrifugal mechanism adds in your particular distributor as the engine speed increases. I recommend a "wired" tachometer that is triggered by the distributor. If you want a tach in the passenger compartment that's fine, but it's tough to rely on that when you're tuning under the hood. I still use one of these when tuning: http://www.sears.com/shc/s/p_10153_...921x00003a&ci_src=14110944&ci_sku=00902165000 Devon
that's exactly the one i have! As you can see it only goes to 2000rpm. So how will i know what my total advance is at 2500rpm as Larry suggested?
Ha! Sorry, I missed that! My old Sears meter reads to 3000 rpm. Now I see why we need to find you a different tach! Of course you can use the Equus tach. Either temporarily wire it so you can see it under the hood or have a helper watch from inside the car. Devon
ha, i thought you were just offering the piston stop. About what time do you pass through San Jose? ---------- Post added at 01:29 PM ---------- Previous post was at 01:28 PM ---------- just to clarify, advancing is turning my distributor clockwise and retarding is counter... my dist is in the front of the engine, i think thats common for most buicks.
:rant: Gah Dammit! ---------- Post added at 01:50 PM ---------- Previous post was at 01:50 PM ---------- I'll take what i can get at this point.
update: I think i may have found the sweet spot. Initial timing at 14* Total timing at 30* The car starts and stops perfectly. When i punch it, it's very responsive. I do not hear any pinging or detonation and it idles at 600-650. There is still a slight shake to the engine, but i think it may be due to the carburetor. I think it may time for a rebuild. When i turn the screws there isn't much response unless i bottom out either one of the screws. Bring them back out (rich) stops affecting the idle at a about 2 turns. then nothing. My vacuum gauge reads about 5 steady and revving to 2000+ hits 20.
Glad your car is running better and now you know how to set the timing. Your vacuum readings sound REALLY low at idle, I would search for a vacuum leak somewhere. I would take up mhgs's offer to visit and have a look.
well, i kind of just guessed with the timing. I had it set at 32* total in the beginning and tried to bring the idle down and smooth out the engine, but it just didnt sound right. So i brought it down to 30 and it made it a little smoother. Maybe im just crazy and maybe 2* wont change anything that much o No: Any idea what the vacuum should be at idle? Maybe that's why the engine is shaking a bit due to a vacuum leak. I still do plan on meeting up with mhgs.
5" at idle is VERY low. I'm not sure you understand how to time the engine. Every time I think you understand, you say something that tells me you don't. Some guys need to be shown. If I lived close by, I would show you myself. Take advantage of mhgs's offer. Let him look at it. Your engine is no where near to running right. A healthy stock engine should make 20" of vacuum at IDLE.
where are you taking the vacuum reading ??...almost sounds like you are on a ported line...which might not be truly closing and showing the 5 inches. With 5 at idle I'm surprised it would even run.
I am taking the reading from here, this is also where my vacuum advance is plugged into. I understood that this was manifold vacuum. I can try it from a source directly on the manifold (behind the carb) and see if it changes. if it's supposed to be at 20 at idle, how high will it go when accelerating? I know that at wide open throttle it will drop, but it usually increases until that point, right?
I am not familiar with that carb however: If you have a ported vacuum source it will give none or very low vacuum at idle and then max out at part throttle under light load. The manifold vacuum will usually give 15-20 inches of vacuum at idle and this will decrease as the RPM and load increases. Under full throttle either vacuum source should be close to zero.
