Howdy

I have been getting braver driving my new stroker build to work a couple times after cam break in and oil change, neighorhood romps etc. My plugs are looking clean, no pinging or knocking, good power and throttle response. The cam and headwork by shady dell gave the motor a very smooth personality and it idles with just a little lope at 900rpm.

My timing is 21 initial, 34 total. My fuel bowls dribble out the sight plugs when the car is nudged. I run an electric pump deadheaded. My IFRs are reduced making the idle screws just right around 1.6 turns out. My metering blocks have the white plastic whistles installed and the rear has jet extensions to keep them submerged on launch. I run pump premium.

If I am cruising and push the clutch the motor returns nicely to idle. If I slowly stop it is fine. If I stop even a little bit hard or turn 90* with the clutch in the car tries to die. When stopping I can leave it in 2nd and feather the clutch to keep the motor spinning then give a throttle blip as I'm almost stopped and she'll stay on, but that's a lot of footwork and sometimes you have to stop faster. On a turn I've been leaving it in gear and just pop the clutch when I get back on the gas.

This morning I tried 1/8 turn out (richer) on the idle screws and raised the curb idle to 1000- it is still stalling on stops and turns. To restart the car wants the throttle open a little, not pump shots, which leads me to believe it's flooding. Unfortunately my wideband is on the injured list.

What are some strategies to work on this problem short of a 1250rpm idle or a dashpot on the throttle? (if there was an easy dashpot kit I would actually not mind a slower return to idle as a bandaid but I haven't seen one)

Thanks Moparts!
radar

What kind of Holley you running? Just a thought from what you have posted, I'd try increasing the IFR's by .002-.003". This will allow you to close the idle mixture screws a bit, maybe 3/4 to 1 turn out. It seems to me that the problem is in the transition circuit. The IFR's feed this circuit.

The factory had the same problem, that's why they installed dashpots on some manual shift cars.

http://www.summitracing.com/parts/hly-11-4/requiredparts

Maybe the secondary throttle blades could be opened a bit?

As asked, what carb 4 starters..............

Couple things to try. Turn the N&S nuts down one flat. Also try a hose between the vents with a cutout in the middle.

I bet it's fuel sloshing away from the front metering plate.

I'd convert to EFI lol

I would try to adj idle mix screwes out 1/2 turn just to see what it does.
My car does the same when im too lean.
It is hard to get a 4 spd carb to run perfect.

It's a frankenstein carb- 750dp metering blocks, original style 950 hp bowls, original style (non idle-eze) 750 HP main body.

The secondaries are open to expose a square of transition slot, the primaries should be in that ballpark. There are .014" wires in all four IFRs. I have adjustable air bleeds but the metering blocks are not tapped for replacable anything.

With the same carb on my old motor it would only stall on a really hard stop after a nice blast or it would generally only act this same way if it was cold like not warmed up yet. Hmm maybe that points to a lean condition like uncovered front metering orifices. It does respond well to a blip and then recovers idle well so maybe that's a good indicator of direction to tune in. Maybe some combo of smaller idle bleeds, richer 4 corner idle setting, higher float level, higher curb idle...

This carb was a touch rich on cruise on my old setup- airgap, 557 cam, ootb edelbrock heads. It seems to run pretty sharp and clean on this new combo- victor 340 intake, sft bullet cam around 247°@.050, .55" lift, ryan j stage II porting on the edelbrocks, 10.2:1.

I kind of expected to have to go a bunch richer with the single plane but it seems happy. There's still acc pump and top end tuning to do but this stalling is the only impediment to generally decent drivability. On paper it should flirt with 500hp at the crank but in the street I doubt I can put more than 3-350 thru the BFG t/a 275/60-15 tires anyway.

I can chase a summer tune and get some new ETs in the spring but right now I just want to feel confident that I'll get where I'm going without a lot of fancy footwork or having to drive wierd to avoid stalling.

I would totally put on a dashpot and thanks for the link- I will do some more research before I request more hand holding on that item. It would have to play nice with my aftermarket throttle bracket and I don't know if they are electric or vac or just a little buffer that the return spring overcomes slowly. My double return springs are not super beefy or strong.

In any case thanks for the responses. I am at work and won't get to wrench till maybe later this week so I want to have a game plan.

Radar

""If I stop even a little bit hard or turn 90* with the clutch in the car tries to die.""

This sounds like fuel is moving around causing a lean spot in the front bowl. I would suggest raising the front float and retest.

when this happened on my cars, it was the secondary fuel bowls being to high. try lowering them. when braking and turning hard, if the level is to high, the fuel gets pushed out the boosters. I have my fuel level just below the site plug.....