Annular 80514 HP1000, I'm close, which way to go?

[Right hand drive]

[dave brode]

Rhd / All,

Note: In the first post on the switch to the 4781, I wrote that it has .025"/.070" air bleeds. That is wrong, it has stock press in bleeds, .025" MABs, .067" PIABs,.0595" SIABs.

Today, I tried .033" PIFR [sec side is closed off, has .035"]. With the .033" IFRs, it really likes 2 turns out, rich spot slightly better. At 1.75 turns out, idle is "ok", rich spot IS still better than .035" IFRs. Less than 1.75 and it drops rpm, doesn't like it.

I will eventually drill/tap the bleeds for set screws, but first I will try .031" IFRs. If that doesn't improve it, I'll go back to .035" IFRs with idle mix screws at best idle, and see how T-Slot restrictors in the front effect it.

Assuming that I'll still be seeking improvement after that round, I'll pull the carb and drill/tap the air bleed for set screws and experiment on IFR/IABs combos as per your advice.

Thank you.
Dave

[rgalajda]

"My problem is a lean sag [16 to17-1] in the 1500-1800 light throttle range on flat ground, where the manifold vacuum gets to maybe 12". More throttle brings the mains on [I assume} and it's good."
Idle circuit and main circuit not overlapping.

Right hand drive wrote
"What was the issue with the factory Holley settings?

Helps to gauge the changes you have made up to now"

Agree. Otherwise just stabs in the dark

[dave brode]

All,

I had a long break due to other house related projects. I'm going to try to make some test and tune events this month. I did try some TSRs experiments before the break, which were encouraging.

I have done some Launch and WOT testing with the 4781 and the HP1000, as I'm going to try to make some test and tune events this month before season end. I'm going to post about jetting and PVRC needs for primary PV vs no PVs and square jetting.

Thanks.

[JETFAST]

signal strength is very important. the swiss cheese e-stack is what gets you past a lazy signal, and with a lazzy signal, over emulsified, you are going to have big globs of fuel you can not burn, or light off in the burn to late, and that is just a waste of fuel. with a long duration camshaft, something like that on the street, needs timing to draw a fair and stable signal. more signal strength at idle and cruise, the wider the range of operation. then you can take all that emulsion out cause its no good after that. keep it turbulent at the booster, instead of all the turbulence in the main well. you can see it, and you can hear it. when you got it right, the motor will usually sound like they are to suck the carb off, at idle. thats signal, if you can not hear it at closed throttle, hard to get fuel out the carb, so you increase the air in the main wells to lift it out, and thats not very good control for a wide range of operation. down at idle, low signal, fine, but wot, it gets dirty. and not very controllable through the range or at wot, other then adjusting the main jet restrictions, and those changes will swing the A/F charge all over the place.

lot easier to control a low simmer of emulsion, then trying to control a raging boil over of vaporization out of the boosters.

[rgalajda]

What the ........ '' the swiss cheese e-stack is what gets you past a lazy signal'' explain this