Idling issues

Ok in need of some help. Had a 1641 shortblock built for me with a scat c25 cam. Put everthing back on and did the cam break-in per the builders instructions. Everything went fine tried to set the timing with 009 and a solex 34 pict 3 couldnt get it to idle at the proper timing. Went and bought an SVDA with the electronic module. before installing that we replaced the intake manifold gaskets just to make sure there were no air leaks, put the SVDA in and still cant get the darn thing to idle at the proper timing. Now the solex 34 pict 3 has a rivet in the butterfly valve for the 009 but would that effect it?

What are you calling proper timing? are you setting timing at idle or at advance?

will it not idle even when cold? did you set the timing to 28-32 at full advance around 3000-3500 rpms? has the pilot jet been pulled and cleaned on the passenger side of the carb? is the idle cutoff switch working properly?

Lose the rivet

We are setting the timing at 3500 with the line plugged at 32 degrees. Car will start but will not hold idle unless choke is moved manually to the top level but as it warms and steps down it stalls out. Pilot jet was pulled and cleaned and adjusted all the way in. The cut off switch is working properly. I've even tried the one that is cut. That I have.

With peeweeman we also backed the pilot jet out a half turn but the idle cut out even faster. With the new Scat c25 cam do we need to change anything else? It's just weird that it idled fine before bottom end rebuilt. Feels like it could intake leak but we shots starter fluid across whole intake a see no significant change in engine rpm on the tach

Does the mixture screw affect the engine speed at all? Did you change jet size? You probably should.

Mix screw does affect speed but not like it did prior to disassembly for block rebuild. We put same carb and distributor back on expecting to only need to set the timing and are baffled by this idle issue. We can keep the car running only by advancing timing up to about 60 degrees at 3500 rpm at that point idle timing is about 30 degrees. 900 rpm

What was it before a 1641? Did you put in bigger pistons? Even just a cam change may need a jet change.

The 1641 was there before the bottom end build. Just the cam is new.

Ran fine with the 1641, 009, & 34pict carb. We removed these from the block, had the crank cam and oil pump replaced in rebuild. Installed all the same external parts and discovered idle issue. Replaced 009 with SVDA and electronic modular hoping to chase it out. Replaced intake gaskets thinking it was induced air leak we created on reinstall. But nothing it getting it back where it used to be before block rebuild

Still think you should try re jetting it. The lift is wanting more fuel and air. You may just be starving the engine. Which is why it runs if you choke it.

Also, the orientation of the SVDA is likely going to be clocked about 90 degrees from where the 009 was positioned, so make double sure all the plug wires are in the correct position.  My cheapo 009 doesn't have the mark for #1 spark plug on the rim, so when I swapped over to an SVDA, the car ran like crap and had me scratching my head for a while until I figured out I figured this out.

Picture I found on samba.
034 SVDA on left, 009 on right. This picture shows their approximate orientation when installed in the engine.

Thanks We caught the orientation as we reassembled. TDC was pointing at #2