: CCC Quadrajet on a 425?



ferrisworld
08-19-12, 02:58 AM
I need to rebuild the carb on my 425, but in the search for mpg, I started researching the CCC carbs. From what I understand, the computer also controls the timing. I take it then that I could use a 368 distributer (got one), build a 368 CCC carb, and use the 368s computer. Or maybe I should get a newer carb and computer from one of the olds 307 cars? I know a lot of people don't like the CCC carbs, but I think it could be a fun project, and less work than converting to EFI. My only concern is whether the smog people would notice/accept it. Guess I could call some up and see.

deVille33
08-19-12, 09:50 AM
You don't memtion which State you live in on your profile, so the State may or may not take action depending on the state regulators. Some States drop restrictions after a car reaches a certain amount of years.
In Taxachusetts, here, the Registry labeled one of the citizens, a local enthusiast, as a tinkerer for his altering of his vehicle. Because of public intervention, the state finally backed off and allowed his alterations.
The 307 CCCs were basically poor examples of GM's engineering to meet government emissions and economy standards, although it did come close. In order to use this carb, you would have to incorporate all the sensors and controls from the Oldsmobile platform and install it into the Cadillac. The carb would not be a basic bolt on, due to the differnce in displacement, over 100 c.u. between the engines. You will benefit from a publication of Doug Roe's QJ Bible. The info in there would help you in determining rejetting and rerodding your QJ to meet your determined requirements.
Read some of Bruce Roe's posts in here. He has had good results from his knowledge of the 425 Fuel Injection system which was designed for this engine.

ferrisworld
08-19-12, 12:39 PM
Well the 307 Q-Jet will bolt on, it just won't be jetted right, right? I got a pretty good Q-Jet book. It doesn't deal with the CCC ones, but in this article http://www.carcraft.com/techarticles/ccrp_0908_qjet_carburetor_rebuild/viewall.html it seems like that doesn't matter.

I'm wondering if maybe the 368 setup would be a better choice since the timing curve might be closer to what a 425 should have?

If I find an EFI setup, I will buy it for sure.

I live in California, guess I should add that to my sig, so yes, I do still have to smog the car. I think I had read something once about doing electronic ignition conversions or something before though, where it might be allowed, so maybe the CCC stuff would be too.

The Ape Man
08-19-12, 08:06 PM
There was no 368 CCC carbonator as far as I know. The 307 system was not bad all things considered except for parts count and the ease of screwing it up. They are a proven design.

IMO you would be better off with throttle body injection and way way better off with sequential port injection.

Someone makes a Ford 460 intake to Cadillac engine adaptor. A port injected tuned intake might just be the ticket IF the actual firing order is similar. Megasquirt stuff looks really good these days.

BRUCE ROE
08-20-12, 12:23 AM
My opinion, updating the spark will have more effect than the fuel system. I put
an electronically programable crank trigger system on a carb engine, and improved
EVERYTHING. The fuel injection helps OEMs meet emissions & improve operation at
extremes, not so much the experimenter. The 3D spark map is far easier & cheaper
to set up, doesn't take your engine down till its been totally tuned. Just start with
the mechanical HEI advance, improve from there. Your old ignition can be a
backup system. Bruce Roe CLC # 14630

deVille33
08-20-12, 09:28 AM
The basic Q-Jet carb has been used for many different GM engines with many different displacements. There have been some variations of design from year to year, but rated cfm ratings have been accomplished by the selection of jets and rods.Rochester never cataloged the cfm ratings to my knowledge, but flows were available from 500 cfm to 800 cfm in stock applications and with some tweeking you could get more. One carb they produced to meet Federal mandated economy blocked off the two rear demnd ports and used only the front venturi and most likely had a flow rating of 450 cfm.

ferrisworld
08-20-12, 11:56 AM
Hmmm. I had posted before about putting in my 368 distributor with the carb, and everyone said it would be a waste of time. Are you saying that's not the case Bruce?

Also when I was at pick n pull, they had a 1980 Deville, and on it's Q-jet it had an electrical connection on the left front of the carb at an angle like I've seen on other CCC Q-Jets, which led me to believe it had one too.

The Ape Man
08-20-12, 09:01 PM
My opinion, updating the spark will have more effect than the fuel system. I put
an electronically programable crank trigger system on a carb engine, and improved
EVERYTHING. The fuel injection helps OEMs meet emissions & improve operation at
extremes, not so much the experimenter. The 3D spark map is far easier & cheaper
to set up, doesn't take your engine down till its been totally tuned. Just start with
the mechanical HEI advance, improve from there. Your old ignition can be a
backup system. Bruce Roe CLC # 14630

My thing is this series of Cadillac engines runs a whole lot better at idle and just off idle with fuel injection as they should have had from day one.

BRUCE ROE
08-20-12, 10:41 PM
Hmmm. I had posted before about putting in my 368 distributor with the carb, and everyone said it would be a waste of time. Are you saying that's not the case Bruce?

Also when I was at pick n pull, they had a 1980 Deville, and on it's Q-jet it had an electrical connection on the left front of the carb at an angle like I've seen on other CCC Q-Jets, which led me to believe it had one too.

An electronically mapped spark advance is better, but it takes some kind of computer with the distributor
to do it. I used one from AUTOSPORTLABS, cheap. Yes the port injected fuel injection does run somewhat
better than a carb, but at a high price. Bruce

Submariner409
08-20-12, 10:54 PM
Bruce, Are you any relation to the QJ guru and manual writer - Doug Roe (HP books, Rochester Quadrajets) ??

ferrisworld
08-21-12, 05:08 AM
Well, I dunno. I guess I'll just keeping looking at pick n pull for an efi 500 or 425 to get the parts from. My dad used to have an 89 lesabre wagon with the 307 and it got up to 23 mpg on several trips though.

BRUCE ROE
08-24-12, 11:15 PM
Bruce, Are you any relation to the QJ guru and manual writer - Doug Roe (HP books, Rochester Quadrajets) ?? No known relation here. I have a terrible time with
Q jets, esp after I wear them out with 200,000 miles & decades of age. Almost enough to drive me to EFI.
Bruce Roe

ferrisworld
08-25-12, 03:22 AM
Now I'm wondering if I should just throw together a 403 with a seville efi setup and megasquirt. Pick n pull has everything I would need almost every time I go. I've only seen an EFI 500 in there once, many years ago, and it wasn't complete. Plus the olds EFI intake is aluminum while on the cad I would forced to use the iron one.

ferrisworld
09-01-12, 03:04 AM
Pick n pull is having a 50% off sale this weekend, but the only thing they have that might be of use is a 1980 Deville's 368. I could pull the aluminum carb intake, and may as well get the carb and computer as well, but I don't know if it's really worth it. How much worse does the 368 intake flow than the iron 425 intake? How much porting would I have to do? Or, I could pull an axle off a 9c1 I guess. I've seen a bunch of those in there lately. Then I'd have discs, 3.08s, lsd, and abs reluctors for probably around $150 or so. Just not sure if I want to get into an axle right now.

Edit: Went ahead and got the intake. Also took the plastic valve covers. Kinda cool that the paint doesn't come off, but then I've heard they don't seal as well.

BRUCE ROE
09-01-12, 09:51 PM
Now I'm wondering if I should just throw together a 403 with a seville efi
setup and megasquirt. Pick n pull has everything I would need almost every time I go. I've only seen
an EFI 500 in there once, many years ago, and it wasn't complete. Plus the olds EFI intake is aluminum
while on the cad I would forced to use the iron one.

The Seville 350 Olds EFI was also used in the 79 Eldo. My 79 Eldo is converted to a 403, the original ECU
retuned. It also has a 76-77 iron intake with the big throttle body. The 78-79 350 used an aluminum
intake with a rather small throttle body, and was highly prone to corrosion at the coolant passages.
Some pictures are on my PHOTOBUCKET. These systems do not use an electronically mapped HEI; just
the old weights, springs, & vacuum canister.

Bruce Roe