jetting problem on the secondary, what´s your opinion

[Austrian455]

Hey,

I rebuilt the cylinder heads of my Centurion.
I spent about 5 hours per head with porting.
All valves are sealing perfect again, heads had been
resurfaced to get good gasket seal.
Took off 0.025 of the heads to rise CR to 9.0
Port matched performer intake, Hooker super comp.
mod. 800 Q-jet, re-curved distributor, MSD coil, 10deg. timing

The car runs good. Idles nice and has much more power.
But I think the secondaries are still running lean.
This video shows it. You can recognize the it starts to stumble when
it´s in 2nd gear under load:
http://www.youtube.com/watch?v=3Oty4xV_KPc
You can hear it best at 0:15 - 0:17

primery´s:
0.074 jets, 0.041 rods
secondary´s:
0.0527 rods

"K" Hanger

high low needle&seat, perf. acc. pump

Here are som further vids. But they don´t show the problem because I didn´t keep the secondary open long enough.
http://www.youtube.com/watch?v=1cA3TCQXtkE
http://www.youtube.com/watch?v=ry9DM3D6VPA

Tell me what you think / what you would try.

[billy bong]

Have tried to adjust the spring tension on the secondary flaper. Tighten 1/2 turn and then try it under a load. Do this untill the bog or flat spot goes away. Hope this helps.
Bill

[Smartin]

I think if the air valve was misadjusted, then the bog would immediately happen when the pedal was floored.

[Austrian455]

BTW, I solved the jetting problem before I gave the car away.
I put 0.0440 DA rods in.
It runs perfect when it´s on operating temp.
No bog or something like that.
Just power when the pedal is floored.
If the next owner wants to get more power out of it, I would say
a TA cam with matched valve springs and a 9 key timing set is the way to go.

Thanks for the help

[gashog]

I highly recommend--->
http://www.cliffshighperformance.com/simplemachinesforum/


Wrote the book on quadrajets.
Very helpful guy,and does fantastic work.
Well worth the money,if your going to have a quadrajet rebuilt.
On top of it all,he helps out anyone who has questions about applications,modifications,and tuning.

:beers:

[BuickLover]

I know I'm late to this party but that didn't sound like a jetting problem to me. Sounded more like ignition and or timing. Did you have a point ignition in that car or change it out with an HEI yet?

BL

[Austrian455]

I think the problem is that I kept the point in.
It runs really good now.
I went to .440 secondaries and put a dist. re-curve kit in.
Now it has full timing in at about 2500 rpm.
In my oppinion the limiting factors are cam, valve springs and points at the moment.
But thanks for the reply.
The dealer I brought the car to wasn´t able to sell the car until now.
Now I´m in the position again to hope that he wont sell till May.
Because in May I should be able to get there and take her home again :Brow:
You can´t imagine how I would miss the car if it sells.

But if she´s still mine in May I´ll order a TA cam, lifter kit, 9-way timing set, valve springs and a electronic conversion kit for the distributor. Maybe a Spectre Ram Air Kit.