I'm building A carbed 4.9,and I am aware of the vacuum advance conversion for this distributor,but I heard it was possible to keep the electronic advance,by using some type of ingnition box. At first I thought this was B.S.,because I searched this site for months,and every single carbed 4.9 I could find had vacuum advance.Then I ran across A coulpe pics of tbi chevy 4x4s,that for some reason had been converted to carbs.They appeared to have the factory distributor w/o vacuum advance and was running a msd box.Unfortunately I was unable to get any info on how that was working.I think the 4.9 distributor and the tbi chevys are almost the same electronically(except for the hall effect). With that said,I am wanting to use the electronic caddy distributor with my carbed 4.9.Any help at all,is appreciated,and please correct me on any misinformation I may have posted.

BTW welcome aboard but if I am not mistaken you are the one converting a 4.9 into a Porsche 924......cool but the electronic distributor will not work as is with a carburated system it has to be modified with a early 80's 4.1 distributor and scrap the internals and replace it with70-80's early Pontiac or Oldsmobile internals, this conversion can be seen on bubbajoexxx website http://www.fortunecity.com/...r/switch/67/id18.htm

With this conversion you can use a msd or mallory ignition box to provide a hotter spark If you need help with the wiring I have the info on how to wire it up.

Thanks for the reply "gunslinger" and yes I am that guy.I hope I'm not looked down on,you have to understand that there are not many forums that deal with the 4.9 caddy in modifed form.I am aware of the vaccum advance mod for this distributor,but I'm still very confused about ignition boxs.I know very little about how they work.For example if someone was boosting a 4.9 PFI and using a BTM box to retard the timing,I do understand it uses manifold pressure for referance,but it has to do something electronically to change the timing right?seems like it would have to over ride the ECM,or they would be fighting eachother.Thats what made me think it was possible to turn the electronic distributor into a "stand alone ingnition" using some type of ingnition box. I'm hoping you guys will educate me,so I'm less confused.........Thanks in advance.

Shoot a PM to Captain Fiero. I believe he is using an MSD (6A?) box with his 4.9. I'm not sure exactly what you are looking for but with him having actually done an ignition mod to this motor I'm sure he will have some helpful info for you.

Someone posted a link to your thread on the other forum about the porsche conversion. There are plenty of interested people here that will be following your progress. I am one of those people. My Dad just picked up a 79 924 for next to nothing. On top of that I am completing a 4.9 swap into a fiero. I probably would not have thought of puting that motor is that car but now you have me thinking. I think you will be very happy with the results. Later.

You'd probably need something like this, where you can program the entire advance curve. Very expensive i would imagine though. Certainly more than a $20 vacuum advance can and an old pontiac distributor. http://www.msdignition.com/ignition_23_7531.htm

quote Originally posted by ChadTanner: I'm building A carbed 4.9,and I am aware of the vacuum advance conversion for this distributor,but I heard it was possible to keep the electronic advance,by using some type of ingnition box. At first I thought this was B.S.,because I searched this site for months,and every single carbed 4.9 I could find had vacuum advance.Then I ran across A coulpe pics of tbi chevy 4x4s,that for some reason had been converted to carbs.They appeared to have the factory distributor w/o vacuum advance and was running a msd box.Unfortunately I was unable to get any info on how that was working.I think the 4.9 distributor and the tbi chevys are almost the same electronically(except for the hall effect). With that said,I am wanting to use the electronic caddy distributor with my carbed 4.9.Any help at all,is appreciated,and please correct me on any misinformation I may have posted.

I forgot to update this thread a long time ago.Not that there will be any interest in this subject for the application of a carbed 4.9 caddy,but i do think its very interesting and could be useful information for at least a few people..

The pictures I ran across of a TbI chevy that had been converted to carb,and appeared to have the factory distributor w/o vacuum advance,is what convinced me,it was possible to turn the electronic distributor into a "stand alone ingnition".

Well,I did track down the info on the truck in question.It was not an easy task,as they were very old school,and had nothing to do with the internet,and had no knowlage their truck had found the internet.However,I was able to track down the image poster,who fortunately was able to help me contact the owner via phone.

What I had been looking at,,, a very mean 383 stroker,292 comp cam,with a large Holly. was in fact using the factory electronic distributor,that came with the 1992 4x4 pickup.So how was that working???

Some very clever persons,with many years of OBD1 tuning experience,thought it would be a great ideal to use the factory ECM as a "stand alone ingnition".Their thinking was,this was better than any distributor available.Why not?? the entire timing curve is programable per RPM and also the knock sensor allows for jagged edge timing performance.Besides thinking it was better,it was free,something they already had.Also being in the OBD1 tuning business,it was just another project.

Form what I understood,This was completed mostly with calabrations of the PROM,which I do understand,and have had some experience with.however there were some other modifications such as (I don't know the correct term) maybe "hard-wiring".which is beyond my knowledge,or at least what I'm able to comprehend in only 10 minutes.

Since this was so interesting to me,I spent lots of time searching the net for more info on this subject and came up with absolutely nothing!!!

Thanks..
Chad

quote Originally posted by ChadTanner: I forgot to update this thread a long time ago.Not that there will be any interest in this subject for the application of a carbed 4.9 caddy,but i do think its very interesting and could be useful information for at least a few people.. The pictures I ran across of a TbI chevy that had been converted to carb,and appeared to have the factory distributor w/o vacuum advance,is what convinced me,it was possible to turn the electronic distributor into a "stand alone ingnition". Well,I did track down the info on the truck in question.It was not an easy task,as they were very old school,and had nothing to do with the internet,and had no knowlage their truck had found the internet.However,I was able to track down the image poster,who fortunately was able to help me contact the owner via phone. What I had been looking at,,, a very mean 383 stroker,292 comp cam,with a large Holly. was in fact using the factory electronic distributor,that came with the 1992 4x4 pickup.So how was that working??? Some very clever persons,with many years of OBD1 tuning experience,thought it would be a great ideal to use the factory ECM as a "stand alone ingnition".Their thinking was,this was better than any distributor available.Why not?? the entire timing curve is programable per RPM and also the knock sensor allows for jagged edge timing performance.Besides thinking it was better,it was free,something they already had.Also being in the OBD1 tuning business,it was just another project. Form what I understood,This was completed mostly with calabrations of the PROM,which I do understand,and have had some experience with.however there were some other modifications such as (I don't know the correct term) maybe "hard-wiring".which is beyond my knowledge,or at least what I'm able to comprehend in only 10 minutes. Since this was so interesting to me,I spent lots of time searching the net for more info on this subject and came up with absolutely nothing!!! Thanks.. Chad

if you can find the computer from an 87 cutlass with the 307 engine it came with computer ignition and a 4 barrel carb the ecm will work with the caddy engine

quote Originally posted by bubbajoexxx: if you can find the computer from an 87 cutlass with the 307 engine it came with computer ignition and a 4 barrel carb the ecm will work with the caddy engine

bubbajoe,"You are a genius!!! "This info is exactly what I have been searching for.You definitely earned a + rating from me.I'm also glad to see you are still around here,and I hope healthy.

Without a doubt,this info is what started the rumer,that the caddy's electronic distributor could be used with a carb setup,but after me getting fourth hand information,it was called "some type of ingnition box" I guess me asking about a ingnition box is what threw everyone for a loop.I think everyone will now be able to see where I was wanting to go with this thread.

I am only vaguely aware that those computer/carb systems exsited and have absolutely no experience with them.I have heard people refer to the car in question as "ya that car has a computer controlled Q-jet".
Everyone will ask is this better than the vacuum advance distributor when running a carb,I sure think so,and GM obvouisly thought so before they finaly put the carb on the shelf for good.

I'm convinced it will work better than a vacuum advance,but is it worth the trouble of doing?probably not.However none of my projects have anything to with "is it worth doing" I no longer enjoy bolting together parts out of a catalog.My enjoyment now comes from popping the hood at the cruise-in,and getting the "WTF face" from even the most knowledgeable car guys,not only could they be confused about what exactly they are looking at,but also have no ideal how it even works.

bubbajoe,even though you have been the greatest help to me on this subject,and searching for more info will now be tons easier,I just have to ask,if you can give me more information,maybe more info on how the ecm works with the caddy distributor.

Thanks..
Chad

quote Originally posted by ChadTanner: bubbajoe,"You are a genius!!! "This info is exactly what I have been searching for.You definitely earned a + rating from me.I'm also glad to see you are still around here,and I hope healthy. Without a doubt,this info is what started the rumer,that the caddy's electronic distributor could be used with a carb setup,but after me getting fourth hand information,it was called "some type of ingnition box" I guess me asking about a ingnition box is what threw everyone for a loop.I think everyone will now be able to see where I was wanting to go with this thread. I am only vaguely aware that those computer/carb systems exsited and have absolutely no experience with them.I have heard people refer to the car in question as "ya that car has a computer controlled Q-jet". Everyone will ask is this better than the vacuum advance distributor when running a carb,I sure think so,and GM obvouisly thought so before they finaly put the carb on the shelf for good. I'm convinced it will work better than a vacuum advance,but is it worth the trouble of doing?probably not.However none of my projects have anything to with "is it worth doing" I no longer enjoy bolting together parts out of a catalog.My enjoyment now comes from popping the hood at the cruise-in,and getting the "WTF face" from even the most knowledgeable car guys,not only could they be confused about what exactly they are looking at,but also have no ideal how it even works. bubbajoe,even though you have been the greatest help to me on this subject,and searching for more info will now be tons easier,I just have to ask,if you can give me more information,maybe more info on how the ecm works with the caddy distributor. Thanks.. Chad

these carb computer ignition systems where desined for the poor gas quality that was out there at the time
they used a standard timming curve with full advance and a retard for the ignition upon reciving a knock signal and a fuel jet valve that resticked the main jets at cruse speed and during deceleration thee carb funtion can be removed and the ignition funtion use alone and work well as the olds timming curve sutes the 4.9 engine well

I was so happy to find that there is a plethora of information about the 307 oldsmobiles with the "CCC" Computer Command Control or computerized carburetor.I guess,I should'nt be surprised that people would be hotrodding their 307.The ccc systems for these cars appear to have been tweeked inside and out.The ecm has obvouisly been hacked decades ago,and every function of the ecm is tunable and the olds enthusiasts have had great results modding their engines retaining the CCC systems.Some have swapped their 307 for the 403,350,and even 455,and still retained the CCC.I even found a very wild 455 with the CCC Q-jet running very respectable ETs.

Here is a very nice website that is home to a 307 olds performance enthusiast.I give so much credit to people that take their time to detail and document such information,that is only of interest to a small group of people.If you look on the left side of the page there is a detailed,but some what simplified explanation of the CCC.basicly describing How and what it controls,and maby more importantly what it does not control.Besides giving credit to the guy for taking his time to share his knowlege and experiences with everyone threw this very nice web page,I also like the looks of the engine swaps he has completed,they appear to be very clean,and well done.
http://performanceolds307.tripod.com/

So far in,my quest for knowlege of this obsolete technology,I am researching the forum at Oldspower.com. At this time it seams to be the greatest resource for info about these systems.I think it may take a little bit of effort,because from what I understand,there were several variations of the system over the years it was in production.The most notable I see,is the use of a knock sensor.It appears only the later ccc models used a knock sensor.
http://www.oldspower.com/vb/index.php?s=

I am very concerned about using a knock sensor with the 4.9 caddy.As we all know,a knock sensor is some what specific to a perticuler engine.I don't have a clue what a 307 sensor would do on a aluminum caddy engine.However I doubt it would let the engine ping undetected,as we know PBJ's turbo 4.9 was using a sensor,and was actually detecting false knock.I have no ideal if that was because of the location of the sensor or because of the different characteristics of the metal in the engine.I realize there are other 4.9s on this forum that are running F-body ECMs,and I assume with a knock sensor,but I have not found any info about how well the senor works,other than their engine does not ping.I am also unsure if it is possiable to know if the sensor is detecting false knock,without having the car on a dyno,but I'm sure a experienced dyno operator can easily spot it.

bubbajoe,I still have more questions for you,I wish I could just borrow your brain,but I guess that would get too messy(lol) I'm slowing gaining knowlege from the olds crowd,but I'm needing to confirm the caddy distributor is a match "electronically" for the 307 ecm.I'm very curious about what you know, because you told me a specific year and model car "87 cutlass".During a conversation with a 307 enthusiast,I was asked,if this had been done before.So I must ask,if you know,if this has been done before.

Thanks..
Chad

quote Originally posted by ChadTanner: I was so happy to find that there is a plethora of information about the 307 oldsmobiles with the "CCC" Computer Command Control or computerized carburetor.I guess,I should'nt be surprised that people would be hotrodding their 307.The ccc systems for these cars appear to have been tweeked inside and out.The ecm has obvouisly been hacked decades ago,and every function of the ecm is tunable and the olds enthusiasts have had great results modding their engines retaining the CCC systems.Some have swapped their 307 for the 403,350,and even 455,and still retained the CCC.I even found a very wild 455 with the CCC Q-jet running very respectable ETs. Here is a very nice website that is home to a 307 olds performance enthusiast.I give so much credit to people that take their time to detail and document such information,that is only of interest to a small group of people.If you look on the left side of the page there is a detailed,but some what simplified explanation of the CCC.basicly describing How and what it controls,and maby more importantly what it does not control.Besides giving credit to the guy for taking his time to share his knowlege and experiences with everyone threw this very nice web page,I also like the looks of the engine swaps he has completed,they appear to be very clean,and well done. http://performanceolds307.tripod.com/ So far in,my quest for knowlege of this obsolete technology,I am researching the forum at Oldspower.com. At this time it seams to be the greatest resource for info about these systems.I think it may take a little bit of effort,because from what I understand,there were several variations of the system over the years it was in production.The most notable I see,is the use of a knock sensor.It appears only the later ccc models used a knock sensor. http://www.oldspower.com/vb/index.php?s= I am very concerned about using a knock sensor with the 4.9 caddy.As we all know,a knock sensor is some what specific to a perticuler engine.I don't have a clue what a 307 sensor would do on a aluminum caddy engine.However I doubt it would let the engine ping undetected,as we know PBJ's turbo 4.9 was using a sensor,and was actually detecting false knock.I have no ideal if that was because of the location of the sensor or because of the different characteristics of the metal in the engine.I realize there are other 4.9s on this forum that are running F-body ECMs,and I assume with a knock sensor,but I have not found any info about how well the senor works,other than their engine does not ping.I am also unsure if it is possiable to know if the sensor is detecting false knock,without having the car on a dyno,but I'm sure a experienced dyno operator can easily spot it. bubbajoe,I still have more questions for you,I wish I could just borrow your brain,but I guess that would get too messy(lol) I'm slowing gaining knowlege from the olds crowd,but I'm needing to confirm the caddy distributor is a match "electronically" for the 307 ecm.I'm very curious about what you know, because you told me a specific year and model car "87 cutlass".During a conversation with a 307 enthusiast,I was asked,if this had been done before.So I must ask,if you know,if this has been done before. Thanks.. Chad

been there done that when I put a 4.5 in a cavalier using the 87 olds computer with the 307 knock sencer mounted at the base of the block with no ill efects

do not use one from a california equiped car as it is not friendly

use the base model from a northern state or a canadian car

[This message has been edited by bubbajoexxx (edited 09-03-2008).]

quote Originally posted by bubbajoexxx: been there done that when I put a 4.5 in a cavalier using the 87 olds computer with the 307 knock sencer mounted at the base of the block with no ill efects do not use one from a california equiped car as it is not friendly use the base model from a northern state or a canadian car

Bubbajoe,You are the greatest!!! Thats what I needed to know.Thanks so much again,I'll update this thread after I make some progress on this system for my carbed 4.9 setup.