I stumbled upon a 4.1L Buick V6 4bbl aluminum intake manifold and was wondering if anyone would have some information on jetting a non electronic Quadrajet carb 4bbl for it. I'm going to be transplanting this intake on a 1983 cutlass supreme with the Buick 3.8L V6. Has someone done this before and have a good starting point for me? what are your thoughts on doing something like this for a backup engine. I'm not looking for performance out of this little 110hp engine just want it to run smooth and be reliable.
CUTLASS Buick V6 4bbl carb jetting/cfm
- Thread starter nycutlass
- Start date
Back in the day it was a fairly cheap swap, just using the ccc 4bbl that came with the intakes. Those carbs were defined and limited to restrict the air flow etc.
Your 3.8 is probably happiest with a holley 390 or edelbrock 500 type carb. The former would be closer to a stock setup, latter might need to be dialed back if stock but has room to grow if/when you added headers and really tried playing with things.
Any reason not to just get a CCC Rochester designed for the 4.1 and slap it on the 3 8? They're out there and your existing computer can run them for you ok. Then you don't need a distributor swap as well.
I have no computer in the car. i would like to have this as a stand alone engine so i can swap it in any car i want. as for the distributor that is a simple conversion from a computer 7pin to a 4 pin with vacuum advanced. i will look into the 390 Holley i wasn't aware they made them that small. i do have Qjets on hand that would be ideal for me .
What year and off what motors? The 80's Canadian non CCC 307 carbs would be near perfect for your 3.8. Super lean idle circuits, lean part throttle and limited secondary opening, like 60 percent. Jets will depend on rods, APT makes a big difference. The secondary probably is already opening plenty on a smog carb for a 3.8. A wideband is a very good tool to get where you need to be.
The Buick 4.1L was a 1982 that's the one i took the intake off of and is going on a 3.8L and its a 1983. the 307 carb is a good idea and a good place to start off with jetting.
If all you want out of it is to be smooth and reliable then I suggest you leave it alone and put the 4bbl intake on the shelf as a conversation peice. I did this swap 25 years ago to a 1980 cutlass with a 3.8 and all it did for it was use more gas than before. In fact I could swear it actually had less power and made the car slower. The only plus was that it did sound neat when the secondaries opened.
Its not just jetting, Qjets often had different circuit layouts depending on application, especially the idle circuits. The idle tubes for those Qjets are smaller than what you can purchase new now. Also the Buick V6 Qjet has a unique throttle lever that is different from Chevy and Olds Qjets.
It would be better to run a computer. You can always get a V6 ECM but I have no idea if the computer harness is usable or hacked up.
now I'm defiantly going to do it with no computer.Similar threads
