Foxy Green Foxbody Build

89 Fox 427 said:
I think I can start fucking with carb.

With our without vacuum advance the problem exists. So I've plugged advance.

10.7 afr at WOT
11.5 to 12 at cruise
Lean spot 16 to 18 still there when I lean into throttle to maintain mph.

Accelerator pump is verified, again, at zero lash.

Needs more transition fuel and less main circuit fuel.

Increase ifr.

And test the lean spot.

Any input from the peanut eaters?
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Power valve may need to open sooner?
 
Is the power valve in sync with the vacuum you’re pulling? Pv should be 1.5 lower than cruising vacuum I BELIEVE. Someone correct me if I’m wrong because it’s been a while since I’ve messed with a holley.
 
89 Fox 427 said:
Paperwork?

Emulsion?

The fuck?
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The emulsion system is what introduces the bleed air into the fuel.
Just ask your AI about "holley carburetor emulsion system", it'll explain it better than I can.
As Willison mentioned, it became fashionable, I guess with Barry Grant, to use a whole bunch of emulsion instead of the two the '60s Holley engineers liked.
Since you have your jets set, and it's leaning out at a higher vacuum than the highest available PV, and the pump circuit can't cover the hole, you mat have to play with the emulsion system.
Or maybe just a bleed change will work.
You can see the system in this photo:

images
 
You can see what an original 750 block looks like.
Those two holes aren't even the final size, they neck down to like .028 or something farther down.
The hole up in the curved part is commonly called the "kill bleed", you can probably ignore that.

images
 
Changing the main air bleeds also changes the timing of when the mains come on, a smaller bleed will bring it on earlier and a larger bleed later.

Regarding the IFRs, they can be in one of two positions. The first is as shown on Steve's picture above with the 4 hole emulsion, the other is the hole below the emulsions. From what I've read the upper position is common in production carbs but better results come from moving it to the lower hole which is for the most part under the fuel level.
 
Did you guys know that when directions say "fill until oil reaches just under the fill plug" on an 8.8 rear end..

That they're not referring to the fill plug on the back of Moser cover.

My 8.8 is basically filled to the top. But I'll have you know, my Detroit locker has been completely silent back there🤷‍♂️🤷‍♂️

life's a dance, you learn as you go
 
Aftermarket companies should include things like that in the instructions.
 
Steve439 said:
Aftermarket companies should include things like that in the instructions.
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I had a custom 9 inch housing built years ago. I called the place that made the components (Chassis Engineering) and asked them how much fluid this thing was going to take. He told me to get the rear level, slide each axle out a bit so the bearing was outside of the housing, and start filling it. When I had gear lube running out of each tube it is full.
 
Full vs proper should be a little more specific.

Mine is full.

Proper is 1/2 that amount.

My axle tubes are so full I'm surprised fluid isn't coming out of the vent
 
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