510_dreamin Posted January 16 Report Share Posted January 16 I recently installed a 123 Distributor into my 510. It requires I set the timing through the ignition curve and so far these are my baselines. The car has an L20b, mild cam, and dual Weber 40 DCOE carbs. It seems to run ok but could use a little more throughout the powerband. Feels like it’s a bit sluggish and holding back. No knocking at all. Any suggestions? Also as I adjust this should I be adding more fuel with the carbs? Any help is appreciated. Quote Link to comment
datzenmike Posted January 16 Report Share Posted January 16 Stock idle advance is 12 but this is artificially low and strictly for emissions. You could run higher at idle to what ever it likes, perhaps 14 or 15 degrees. Idle has only a whisper of air and fuel, just enough to keep the engine spinning. In effect 120 at idle is retarded compared to where the engine would like to be. This will reduce emissions but dumps a lot of heat into the cooling system through the exhaust port walls and wastes energy that could be used to spin the engine. This is because the molecules are not crammed tightly together and the flame front moves more slowly. Normally the vacuum advance adds this advance for strictly part throttle. Full throttle has more molecules tightly compressed together so it burns faster and need less advance. Maximum advance (static/and centrifugal) on an L series is usually 32 degrees when revved up. Your graph shows 340 You might also try bringing in the maximum advance (320) before 3k. The 'Red Line' on a 86mm stroke L20B is 7,000. With dual carbs and some cam you should easily be capable of that. The stock engine is running out of beans before 6k. Quote Link to comment
510_dreamin Posted January 16 Author Report Share Posted January 16 27 minutes ago, datzenmike said: Stock idle advance is 12 but this is artificially low and strictly for emissions. You could run higher at idle to what ever it likes, perhaps 14 or 15 degrees. Idle has only a whisper of air and fuel, just enough to keep the engine spinning. In effect 120 at idle is retarded compared to where the engine would like to be. This will reduce emissions but dumps a lot of heat into the cooling system through the exhaust port walls and wastes energy that could be used to spin the engine. This is because the molecules are not crammed tightly together and the flame front moves more slowly. Normally the vacuum advance adds this advance for strictly part throttle. Full throttle has more molecules tightly compressed together so it burns faster and need less advance. Maximum advance (static/and centrifugal) on an L series is usually 32 degrees when revved up. Your graph shows 340 You might also try bringing in the maximum advance (320) before 3k. The 'Red Line' on a 86mm stroke L20B is 7,000. With dual carbs and some cam you should easily be capable of that. The stock engine is running out of beans before 6k. Thanks for the insight! I’m learning this all as I go with the car. So it might be worth it to raise the advances up to 32 degrees before 3k rpm and taper off from there? How does this effect carb tuning? Should I adjust them as well? Quote Link to comment
Crashtd420 Posted January 16 Report Share Posted January 16 8 hours ago, 510_dreamin said: I recently installed a 123 Distributor into my 510. It requires I set the timing through the ignition curve and so far these are my baselines. The car has an L20b, mild cam, and dual Weber 40 DCOE carbs. It seems to run ok but could use a little more throughout the powerband. Feels like it’s a bit sluggish and holding back. No knocking at all. Any suggestions? Also as I adjust this should I be adding more fuel with the carbs? Any help is appreciated. You can also ad points to the table to make a smooth curve from idle to full timing.... I have a 123 distributor on my moded L16 with high compression..... I run 15degrees at 750 rpm.... And I think all in I'm at 32.... I believe you want that all in before 3000 rpm.. And I keep it at 32, I don't think you want it to taper off as you go to higher rpms..... Also if your not using the vacuum advance you may want to erase the map it has, maybe screen shot it before you do... I have mine connected to the manifold only to monitor not to adjust the curve so I zero mine out... Last I never had to adjust the carburetor based on the timing changes I made..... You might think about also adding an air fuel ration gauge to see how the carburetors are doing.... A nice wide band system can real help dial things in... Quote Link to comment
510_dreamin Posted January 16 Author Report Share Posted January 16 27 minutes ago, Crashtd420 said: You can also ad points to the table to make a smooth curve from idle to full timing.... I have a 123 distributor on my moded L16 with high compression..... I run 15degrees at 750 rpm.... And I think all in I'm at 32.... I believe you want that all in before 3000 rpm.. And I keep it at 32, I don't think you want it to taper off as you go to higher rpms..... Also if your not using the vacuum advance you may want to erase the map it has, maybe screen shot it before you do... I have mine connected to the manifold only to monitor not to adjust the curve so I zero mine out... Last I never had to adjust the carburetor based on the timing changes I made..... You might think about also adding an air fuel ration gauge to see how the carburetors are doing.... A nice wide band system can real help dial things in... thank you so much! Quote Link to comment
datzenmike Posted January 16 Report Share Posted January 16 Hold the 32 max advance. The engine as it revs higher and higher has less and less time to burn it's fuel so the advance has to be that high. Less than about 32 degrees and the combustion peak pressures occur too late when the piston is too far down the cylinder and accelerating away 2 Quote Link to comment
510_dreamin Posted January 16 Author Report Share Posted January 16 3 hours ago, datzenmike said: Hold the 32 max advance. The engine as it revs higher and higher has less and less time to burn it's fuel so the advance has to be that high. Less than about 32 degrees and the combustion peak pressures occur too late when the piston is too far down the cylinder and accelerating away thank you! Quote Link to comment
mojojojo78 Posted March 21 Report Share Posted March 21 @510_Dreamin, Hows that 123 Distributor working out for you? Quote Link to comment
datzenmike Posted March 21 Report Share Posted March 21 He was last here Jan 19 just after the last post. Quote Link to comment
Crashtd420 Posted March 22 Report Share Posted March 22 15 hours ago, mojojojo78 said: @510_Dreamin, Hows that 123 Distributor working out for you? Since he hasn't been here I'll give you an answer.... I have been running mine for 5 years now and they are flawless... Excellent build quality.... The only issue I have ever had was connecting to the blue tooth.... it has never liked the extreme cold.... This doesn't matter much because it only effects the monitoring and tuning not the actual running.... once warmed up it connects no problem... The only possible issue would be using the security feature when it's that cold... you'd be locked out till the Bluetooth connected.. I think they have a usb programmable unit to.... but no monitoring... Quote Link to comment
mojojojo78 Posted March 22 Report Share Posted March 22 Thanks Crashtd420. I have been looking at them recently. Now I just need a few hundred bucks. 1 Quote Link to comment
510_dreamin Posted March 22 Author Report Share Posted March 22 59 minutes ago, Crashtd420 said: Since he hasn't been here I'll give you an answer.... I have been running mine for 5 years now and they are flawless... Excellent build quality.... The only issue I have ever had was connecting to the blue tooth.... it has never liked the extreme cold.... This doesn't matter much because it only effects the monitoring and tuning not the actual running.... once warmed up it connects no problem... The only possible issue would be using the security feature when it's that cold... you'd be locked out till the Bluetooth connected.. I think they have a usb programmable unit to.... but no monitoring... To be honest it’s a solid product for me but I haven’t been able to get the tune really dialed in. It feels like it’s sluggish no matter what I do, doesn’t rev as freely as it should, and doesn’t like to up hills and will spark knock. It’s been a lot of trial and error and adjusting the tune to try to dial it in but it’s never quite “there” This is my current set up that has been ok but leaves much to be desired: anyone have any suggestions? L20b, dual Webbers, mild cam 1 Quote Link to comment
Crashtd420 Posted March 22 Report Share Posted March 22 49 minutes ago, 510_dreamin said: To be honest it’s a solid product for me but I haven’t been able to get the tune really dialed in. It feels like it’s sluggish no matter what I do, doesn’t rev as freely as it should, and doesn’t like to up hills and will spark knock. It’s been a lot of trial and error and adjusting the tune to try to dial it in but it’s never quite “there” This is my current set up that has been ok but leaves much to be desired: anyone have any suggestions? L20b, dual Webbers, mild cam One thing you can try is adding a few more points .... I can grab a screen shot later of what my current curve is but this is how I would have set it up..... You can keep the #1 as is or even bump that to 15 to match #2.... what are you idling at? So from 2 on.... #2 750 - 15 #3 1125 -18 #4 1500 -21 #5 1875 - 24 #6 2250 - 27 #7 2625 - 30 Add a point 8 and 9 #8 3000 - 31(32) #9 8000 - 31(32) You can even add a few more points and stretch it a little more. I think i added as many as it would allow... from this you can manipulate it a little more... Say you want a little more or less at 2000 rpm or if wanted to bring the full advance down to 2800 rpm ..... Did you have the same engine combo before you added the 123? I chased some issues that I blamed on the distributor and it ended up being fuel related..... 1 Quote Link to comment
iceman510 Posted March 22 Report Share Posted March 22 There is the old adage- If you think it's fuel, it's ignition. If you think it's ignition, it's fuel. Webers tuned properly? 2 1 Quote Link to comment
510_dreamin Posted March 22 Author Report Share Posted March 22 5 hours ago, Crashtd420 said: 5 hours ago, Crashtd420 said: One thing you can try is adding a few more points .... I can grab a screen shot later of what my current curve is but this is how I would have set it up..... You can keep the #1 as is or even bump that to 15 to match #2.... what are you idling at? So from 2 on.... #2 750 - 15 #3 1125 -18 #4 1500 -21 #5 1875 - 24 #6 2250 - 27 #7 2625 - 30 Add a point 8 and 9 #8 3000 - 31(32) #9 8000 - 31(32) You can even add a few more points and stretch it a little more. I think i added as many as it would allow... from this you can manipulate it a little more... Say you want a little more or less at 2000 rpm or if wanted to bring the full advance down to 2800 rpm ..... Did you have the same engine combo before you added the 123? I chased some issues that I blamed on the distributor and it ended up being fuel related..... thank you so much. I will try this set up and see how it does. same set up as before. My matchbox went out and the shop I went to said the 123 was the best way to go forward. Problem was it came untuned. I have been trying since to get it going the right way but it’s a big learning curve for me. I could take it to a tuner around here but im really trying to learn to do as much as I can myself. The shop also swapped out my leaky webbers for rebuilt webbers they had and I think I have them dialed in ok Quote Link to comment
510_dreamin Posted March 23 Author Report Share Posted March 23 6 hours ago, 510_dreamin said: thank you so much. I will try this set up and see how it does. same set up as before. My matchbox went out and the shop I went to said the 123 was the best way to go forward. Problem was it came untuned. I have been trying since to get it going the right way but it’s a big learning curve for me. I could take it to a tuner around here but im really trying to learn to do as much as I can myself. The shop also swapped out my leaky webbers for rebuilt webbers they had and I think I have them dialed in ok update. Ran smoother with this timing set up. Any suggestions for when it gets some spark knock going uphill? Still feels sluggish going up hills Quote Link to comment
Crashtd420 Posted March 23 Report Share Posted March 23 8 hours ago, 510_dreamin said: update. Ran smoother with this timing set up. Any suggestions for when it gets some spark knock going uphill? Still feels sluggish going up hills Not sure of that.... have a read here... https://www.motortrend.com/how-to/engine-detonation-knock-explained/ What rpm are you at when you get going up a hill? Quote Link to comment
datzenmike Posted March 23 Report Share Posted March 23 If it's pinging under load, then the ignition is too advanced. Every engine is different though stock are the most together. If modified then more different. High compression and more volumetric efficiency will require less advance. Higher air pressure, as in at sea level and higher ambient air temperature or running hotter thermostat will also. High humidity will lessen the need for advance. Quote Link to comment
510_dreamin Posted March 23 Author Report Share Posted March 23 What about map curve? Any baseline settings for that? at rpm it’s in the low rpm’s climbing up at wot it will spark knock Quote Link to comment
Z23T Posted March 23 Report Share Posted March 23 How did it run before the 123 and carb swap? Quote Link to comment
Crashtd420 Posted March 23 Report Share Posted March 23 1 hour ago, 510_dreamin said: What about map curve? Any baseline settings for that? at rpm it’s in the low rpm’s climbing up at wot it will spark knock Do you mean for the vacuum advance? With the side drafts we don't have a proper way to read it like the downdraft... I have mine connected to the manifold just to see what it shows but have never tried to build a map for it... Quote Link to comment
510_dreamin Posted March 23 Author Report Share Posted March 23 55 minutes ago, Z23T said: How did it run before the 123 and carb swap? It ran good. Felt quick and light on its feet. Rarely if ever any spark knock. No problem climbing hills. Then the ignition and carb were changed at the same time and it’s been a struggle the past almost year Quote Link to comment
510_dreamin Posted March 23 Author Report Share Posted March 23 30 minutes ago, Crashtd420 said: Do you mean for the vacuum advance? With the side drafts we don't have a proper way to read it like the downdraft... I have mine connected to the manifold just to see what it shows but have never tried to build a map for it... here is the one in the 123 app. I set it with some stuff I found online Quote Link to comment
Crashtd420 Posted March 23 Report Share Posted March 23 3 hours ago, 510_dreamin said: here is the one in the 123 app. I set it with some stuff I found online If you are using a map curve where are you getting your vacuum source from.... Maybe try it with out the map curve and see how it runs..... Kind of sucks you had to change both the carburetor and distributor at the same time.... Do you know if the old and new carburetors are setup identically? Quote Link to comment
510_dreamin Posted March 23 Author Report Share Posted March 23 28 minutes ago, Crashtd420 said: If you are using a map curve where are you getting your vacuum source from.... Maybe try it with out the map curve and see how it runs..... Kind of sucks you had to change both the carburetor and distributor at the same time.... Do you know if the old and new carburetors are setup identically? Unfortunately I have no idea. They’re the same model carbs (40dcoe) but that’s all I know. I was surprised to see them changed out by the shop in the first place. I asked for the ones I had to serviced and it turned into a swap out since mine allegedly needed a rebuild. Quote Link to comment
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