 Giving Up On Vacuum Advance |
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| Ansbacher |
 Jan 18 2019, 06:22 PM
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Senior Member  Group: Members Posts: 689 Joined: 4-July 14 From: Tampa Bay, Florida Member No.: 17,589  |
Car = '74 2.0 Liter, Dual Dellorto Carbs
For years I have been 'adequately" running an 009 mechanical only distributor. Finally took the pervasive advice out there to go with a vacuum advance dizzy from a 1.8L 914. Since only one of my Dellorto carbs had an existing vacuum port (ported type), I had to drill a port in my other one (no problem there). I used good quality anti-pulse valves in the lines and measured a maximum vacuum of 12 inches of mercury with partial throttle. Installed the 1.8 dizzy and set the timing, first without the vacuum lines attached. To satisfy my usual 30-32 degrees at 3500 RPM, the idle timing had to be at about 5-6 degrees (quite low for my setup which is happier at about 10 degrees. When I attached the vacuum lines my timing at 3500 RPM went sky high into the 40s. This seems way too high. Is this normal? Overall, I found the car to run better without the vacuum attached and the carbs plugged off. Am I doing something wrong here? I don't like the numbers I am getting. Everyone said this was the way to go with carbs, but I am not seeing results. Advice appreciated. Ansbacher |
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| cgnj |
Jan 19 2019, 10:10 AM
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Senior Member Group: Members Posts: 665 Joined: 6-March 03 From: Medford, NJ Member No.: 403 Region Association: None 
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How much vacuum @ idle? How much @ 3k?
7.5 degrees @ 800-900 rpm would be correct. I think you are in the ballpark. High vacuum, low load you want to advance to increase mpg. The 10 degrees advance with the 009 is immaterial. It is compensation for the short curve. |
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| Ansbacher |
Jan 19 2019, 03:05 PM
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#3
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Senior Member Group: Members Posts: 689 Joined: 4-July 14 From: Tampa Bay, Florida Member No.: 17,589 |
QUOTE(cgnj @ Jan 19 2019, 11:10 AM)  How much vacuum @ idle? How much @ 3k? 7.5 degrees @ 800-900 rpm would be correct. I think you are in the ballpark. High vacuum, low load you want to advance to increase mpg. The 10 degrees advance with the 009 is immaterial. It is compensation for the short curve. Since I am using ported vacuum, I have 0 vacuum at idle. It doesn't kick in until the butterfly starts to open (as it should). At 3K I have 12 inches HG. The car is much more responsive on pull out when the idle timing is above 8 or so degrees. With this distributor I can't keep it under my target 32 degrees at 3500 RPM when I set idle to anything above 5 degrees, and that is WITHOUT vacuum hooked up. Add the vacuum and it really goes off the chart, I lose power, and it starts to ping when I tromp on it. This is my dilemma. Ansbacher |
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Posts in this topic
Ansbacher Giving Up On Vacuum Advance Jan 18 2019, 06:22 PM
nditiz1 Ditch that distributor and get the correct one for... Jan 18 2019, 11:11 PM pete000 The 123 Dist is the way to go and no need for vac ... Jan 19 2019, 01:15 AM Tbrown4x4 I'll be watching this with interest. I'm g... Jan 19 2019, 03:57 AM nditiz1 I can't find the diagram right now, but someon... Jan 19 2019, 07:57 AM BK911 I've been running an 009 with carbs on a 1.7 f... Jan 19 2019, 08:17 AM
nditiz1
I've been running an 009 with carbs on a 1.7 ... Jan 19 2019, 08:22 AM
Rand
I've been running an 009 with carbs on a 1.7 ... Jan 28 2019, 02:16 PM 72hardtop
I've been running an 009 with carbs on a 1.7... Jan 28 2019, 08:52 PM tmessenger SVDA 034 here's what they say for timing: Use... Jan 19 2019, 09:13 AM tmessenger Mechanical advance springs fatigue with age, with ... Jan 20 2019, 09:50 AM 914_teener I went through a tremendous amount of effort to fi... Jan 19 2019, 04:14 PM pete000 I love my blue tooth programmable 123 so easy and ... Jan 19 2019, 04:35 PM porschetub My research indicated the anti pulse valve is only... Jan 19 2019, 08:14 PM Mark Henry Engine I just built for a customer, 914 2056cc wi... Jan 19 2019, 10:13 PM Mark Henry I've had a couple guys ask about the linkage, ... Jan 20 2019, 09:42 AM Ansbacher Answers to some questions posed of me:
Yes, I am ... Jan 20 2019, 11:33 AM r_towle Based upon what is going on, and your last questio... Jan 20 2019, 07:44 PM 72hardtop Don't attempt to 'T' the lines togethe... Jan 22 2019, 03:00 AM Ansbacher
Don't attempt to 'T' the lines togeth... Jan 22 2019, 12:02 PM 72hardtop
Don't attempt to 'T' the lines toget... Jan 22 2019, 01:15 PM IronHillRestorations One thing I forgot to mention is that the 1.8 dist... Jan 22 2019, 06:48 AM Red72 Jumping in here, and I'm sorry to hijack it so... Jan 28 2019, 11:21 AM tmessenger I went through this with a Triumph TR3 a couple of... Jan 28 2019, 12:40 PM Rand Did you just suggest that you can create so much h... Jan 28 2019, 09:05 PM 72hardtop
Did you just suggest that you can create so much ... Jan 29 2019, 02:42 PM Rand Let me take this second to say that I respect Joe ... Jan 28 2019, 09:21 PM MarkV No doubt fuel injection is better. Many of us have... Jan 28 2019, 09:22 PM 914_teener Ok....I'm an EFI guy so for carbs it's th... Jan 29 2019, 04:30 PM 72hardtop
Ok....I'm an EFI guy so for carbs it's t... Jan 29 2019, 05:04 PM 914_teener https://web.archive.org/web/20001007043902/...ch/d... Jan 29 2019, 04:49 PM 914_teener Well then another dumb bunch of questions:
Isn... Jan 29 2019, 06:49 PM 72hardtop Corrected. Got ahead of myself there. Ported vac a... Jan 30 2019, 10:46 PM tmessenger Ported vacuum with vac port covered by the throttl... Jan 31 2019, 08:23 AM cgnj
Ported vacuum with vac port covered by the thrott... Jan 31 2019, 08:31 PM tmessenger There are 11 years of knowledge in those 99 pages.... Jan 31 2019, 10:06 PM 72hardtop
Ported vacuum with vac port covered by the thrott... May 8 2019, 03:54 PM 72hardtop You can garner a lot from that thread with the fir... Jan 31 2019, 11:18 PM tmessenger 72hardtop
Sounds like we have very similar engine... Feb 1 2019, 01:28 PM 72hardtop
72hardtop
Sounds like we have very similar engin... May 8 2019, 03:47 PM |
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