help with NA V6 tuning

[gearhedjon]

Hi just rebuilt my NA V6. It Has a stock rebuild with stock compression. Poston's cam, Kenny Bell intake 78 exhaust manifolds- no dog leg on the passenger side, true dual exhaust,200R4 trans with shift kit and 3:73 gears.I am currently running a feed back carb with this set up. My problem is I can't even spin the tires! When I punch it it bogs and won't go Yes I have the secondaries tuned and the carb is tuned right too. I even drilled the accelerator arm for some more pump shot which helped some. I believe it's just to lean for my set up. Help! I am thinking of sacrificing the gas mileage and returning it to a stock quadrajet and distributor. Any ideas? Thanks

 

[TurboBuickSix]

Yeah but you thought of it already...It's hard to beat a Q-jet when they are put together right and the economy os not to shabby if your just cruising with the primaries open.

 

[fuzzyGN]

The Kenne Bell with stock compression won't perform as well as a stock 4.1L manifold but it shouldn't be the cause of your bog. Several things come to mind. First, make sure the weights and springs in the distributor are in good shape. What size pipes do you have? Stock compression doesn't need much. On a mild build I did 2" dual exhaust worked well but it had more bottom end with the stock Y pipe configuration. What converter are you running? I spent a huge amount of time tuning my carb and rebuilt twice. Evenyually I got another one and rebuilt it. Better but still not 100%. The feedback style can be even more tricky. One thing I do know if the shaft bushings are worn they act crazy. Again, I am not sure if there is one sole cause but it could be the combo isn't quite right making it tougher to tune. The first time I sent my Vega down the track it ran a 16.8 at about 85 MPH. after about a year of tuning it now runs a 14.6 at 95. It usually isn't an overnight deal to get them right. I think I still have more left in it too.

 

[unboostedV6]

What are the cam specs and how much torque converter do you have ? GB

 

[gearhedjon]

The exhaust starts out as two seperate pipes going into the hi flow convertor then splits off into two seperate pipes all the way back. The pipes are all 2" The convertor is a 2200 stall it is a stock grand national. The cam I can't remember the specs but I think it starts at 2000RPM to 5000 RPM. The computer controlled distributor has no springs as it is computer controlled. The motor apears to run quite lean even though the carb is tuned corectally. If the concenus is to replace the carb with a stock quadrajet and vacuum advance distributor then I "ll try that. Does anyone have a stock distributor for sale? Older Quadrajet? Thanks

 

[unboostedV6]

I couldn't make a Q-jet acc pump shoot enough for long enough to make it work on a Weiand 7541, which is very similar to the KB intake. It needs much more pump volume. Maybe the NHRA S/S carb guys, such as Hedworth,could help you out. Or, switch out the intake for a stock 4.1 manifold and discover throttle response. Hope this helps...GB

 

[charlief1]

Three possibles on your problem. Either you're getting to much fuel. (is there black smoke coming out of the back?) You aren't getting enough volume of fuel. (restricted fuel flow) Or your timing is falling on it's face. If you have access to a scanner not a code reader you can pull up the raw data and see whether you're getting retarded timing or if the carb is the problem.

 

[gearhedjon]

No black smoke out the tailpipes on accel. Will the 4.1 intake work with my present setup? Anybody have a 4.1 intake for sale?

 

[fc227]

How do the spark plugs look ?

 

[charlief1]

One just ended on evil-bay. Do a search for buick 231 or 252 and you will probily find on in a week or two. I personally prefer the Holly. It still has the egr if you want to use it and which ever carb you want to use you can.