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Re: Spark curve
[Re: RoyceFlo73]
#217257
02/07/09 10:43 PM
02/07/09 10:43 PM
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Joined: Mar 2007
Posts: 3,285
West Coast, USA
jbc426
master
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master
Joined: Mar 2007
Posts: 3,285
West Coast, USA
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Are you hooking the vacumn advance to a manifold vacumn source or to the spark port vacumn source?
There are a lot of variables that come into play when determining the best curve to use for a given application, but in general, some would say to skip the vacumn advance, run more initial, less advance and limit your total timing to 38 or less.
It all depends on what your engine/car combination is. More information would help. There are a lot of knowledgable people on this site, but they need more info to help you get started towards sorting this out.
1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 4.10's
1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3800 stall lock-up converter and 4.30's (closest thing to an automatic 5 speed going)
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Re: Spark curve
[Re: RoyceFlo73]
#217259
02/08/09 08:08 AM
02/08/09 08:08 AM
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Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
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Why is the idle speed so high? Wild cam? The vac adv amount is OK. You want your initial ~10 btdc with or without vac adv(whichever your eng/cam runs best with). You need enough(initial) adv so it will idle right with that cam but yet not go over 35(checked w vac adv disconnected) & since you have had it at 10 & it ran I'd put it back there & work on lowering your idle speed & each time resetting your initial to 10. 24 initial is way too much
live every 24 hour block of time like it's your last day on earth
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Re: Spark curve
[Re: Dodgem]
#217261
02/08/09 01:11 PM
02/08/09 01:11 PM
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Joined: Oct 2007
Posts: 3,893
Oregon
hooziewhatsit
master
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master
Joined: Oct 2007
Posts: 3,893
Oregon
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 Try moving the vac advance to the ported port, rather than full manifold vacuum. My truck was just like you describe, stuttery from a stop, then woke up. Once I went to ported vacuum (and reset timing, etc), it was great off the line. -Dave
If you ever find yourself in a fair fight, your tactics suck.
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Re: Spark curve
[Re: Dodgem]
#217264
02/11/09 03:27 AM
02/11/09 03:27 AM
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Joined: Jan 2009
Posts: 374
CONNECTICUT
RoyceFlo73
OP
enthusiast
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OP
enthusiast
Joined: Jan 2009
Posts: 374
CONNECTICUT
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No, I wish it were a BBD. I have a stromberg WW. Have no idea how that found its way onto the motor, i thought all were stock with BBDs and i bought the engine from a guy who did nothing but restorations, seems like a carb is an obvious thing to get wrong in an all original resto. Anyways, I'm pretty sure i have the vacuum advance in the right spot. I have a stromberg WW. The vacuum advance is plugged into a port on the back of the carb right above where the PCV is plugged into. The V.A. port is not below the throttle plate, its half way up. My ideas from here are to frig with the mixture as much as possible to allow the idle to drop until I don't get any vacuum from that port. As of right now, if i unscrew the idle screw any more, the engine wants to stall. So i figure I'll lean it a little bit and keep dropping it. I have to get a vacuum gauge maybe, that could probably help get best mixture. Then, i'll play around with the timing until i can get it right. I set the intitial (with V.A. plugged) at 10btdc. With the V.A. to the carb i shouldnt see any more than 14btdc right?(at idle). Because right now I have 24btdc once i attach the V.A. 
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Re: Spark curve
[Re: Dodgem]
#217267
02/11/09 08:49 PM
02/11/09 08:49 PM
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Joined: Jan 2009
Posts: 374
CONNECTICUT
RoyceFlo73
OP
enthusiast
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OP
enthusiast
Joined: Jan 2009
Posts: 374
CONNECTICUT
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I advanced the timing to about 14btdc. I adjusted mixture screws and got it to idle low, i still have some vacuum at idle, but not a lot. When I plug the V.A. in i adjusted it where i have a few degrees of advance, but it seems to run a little better.
The WW is close to a carter BBD, slightly different. I will make due with this setup for a little while. I have a M1 manifold, TQ, and 340 cam that is going in next month when its a little warmer to work on it. I'm gonna get a new distributor too, this wysco kinda sucks. When playing with it today, i noticed the cap doesn't even stay clamped down perfectly, it shifts a little. Plus, i can't get any tech help from them, they refer me to dealers and such, who help as much as they can but can't seem to answer all my questions. I'll get my old points back in with the petronix Electric ignition.
RIght now, it drives. It's slow, but then again everyone said the 273 would be. Especially since i think i only have 2.94s or something like that for the rear end. The engine seems to wanna work to rev up, as soon as i find some leaf springs i want i am going to fix up the rear end with 3.55s as well.
As it is now, from a dead stop if i snot it, i can get the tires to spin for about 20-30 feet. Yet, if i'm even slighly moving at maybe 5mph or so and snot it, it won't spin em, it'll kinda just plod along.
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Re: Spark curve
[Re: RoyceFlo73]
#217270
02/11/09 10:40 PM
02/11/09 10:40 PM
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Joined: Jun 2006
Posts: 5,163
CT
GTX MATT
master
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master
Joined: Jun 2006
Posts: 5,163
CT
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Quote:
I advanced the timing to about 14btdc. I adjusted mixture screws and got it to idle low, i still have some vacuum at idle, but not a lot. When I plug the V.A. in i adjusted it where i have a few degrees of advance, but it seems to run a little better.
The WW is close to a carter BBD, slightly different. I will make due with this setup for a little while. I have a M1 manifold, TQ, and 340 cam that is going in next month when its a little warmer to work on it. I'm gonna get a new distributor too, this wysco kinda sucks. When playing with it today, i noticed the cap doesn't even stay clamped down perfectly, it shifts a little. Plus, i can't get any tech help from them, they refer me to dealers and such, who help as much as they can but can't seem to answer all my questions. I'll get my old points back in with the petronix Electric ignition.
RIght now, it drives. It's slow, but then again everyone said the 273 would be. Especially since i think i only have 2.94s or something like that for the rear end. The engine seems to wanna work to rev up, as soon as i find some leaf springs i want i am going to fix up the rear end with 3.55s as well.
As it is now, from a dead stop if i snot it, i can get the tires to spin for about 20-30 feet. Yet, if i'm even slighly moving at maybe 5mph or so and snot it, it won't spin em, it'll kinda just plod along.
Thats how my 273 is. Where in CT are you? Ive got a 340 cam in mine as well.
Now I need to pin those needles, got to feel that heat
Hear my motor screamin while I'm tearin up the street
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Re: Spark curve
[Re: RoyceFlo73]
#217275
02/13/09 01:43 AM
02/13/09 01:43 AM
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Joined: Jan 2003
Posts: 5,791
Hamilton, Ontario Canada
Magnum
master
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master
Joined: Jan 2003
Posts: 5,791
Hamilton, Ontario Canada
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Quote:
its kinda a pig at first, then it wakes up.
Which vacuum port is connected has nothing to do with your power problem. Either port will have ZERO vacuum at wide open throttle so save the port vs manifold vacuum for another thread. Oh, we did that 100 times.
How much of a pig is it? It's a 273, that's pretty much how they are until you spin them a bit.
Do not remove the vacuum pot completely. If you chose not to run it, just leave it disconnected.
Report back with your total timing and what rpm it comes in at. Also need more info on the engine and drivetrain.
I would try more initial timing. Whatever your starter will handle is probably barely enough.
69 Super Bee, 93 Mustang LX, 04 Allure Super
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