3810 Holley Discrepancy

[Gene M.]

[Timothy B.]

Re: 3810 Holley Discrepancy

Gene,

The 122-65 jet size seems to correlate to the primary side, the 122-71 may be equal to the .076 hole in the secondary metering plate which in my experience is the correct size main restriction for the #22 plate. Somewhere in the archives there may be a Holley jet size/hole chart, maybe someone will post it.

[Gene M.]

Re: 3810 Holley Discrepancy

Tim do you think the spec of a .076” hole and an actual measure with pin gauge of .073” hole still be in spec for this #22 plate?

I can understand making a hole bigger but not smaller..........

[Gerard F.]

Re: 3810 Holley Discrepancy

Gene, Tim,

Take a look at this thread from the archives. From post #6 on there is a discussion of the pinout specs for the 3810.

https://www.forums.ncrs.org/showthre...=Holley+pinout

Gene, I think you could drill out the #22 metering plate from .073 to .076. Also check the main body vent holes. I have found some with undrilled vents which can cause siphoning and flooding

[Timothy B.]

Re: 3810 Holley Discrepancy

Tim do you think the spec of a .076” hole and an actual measure with pin gauge of .073” hole still be in spec for this #22 plate?

I can understand making a hole bigger but not smaller..........

Is it possible there is some corossion around the hole thus closing it some, or could your drill bit be slightly oversized. That being said. 073 will work fine, I think jet sizes flow differently than just the hole size like what's in the metering plate.I don't know if Jerry's post makes reference to that, I have not opened the link to read.


Hi Jerry, it's good to hear from you. You lost your buddy earlier this year..

[Gene M.]

Re: 3810 Holley Discrepancy

Thanks Jerry and Tim,

I have the second meterplate that I’ve resized to .076” and see how that works out. The biggest task was making all three carburetor air horn surfaces flat in addition to the meter plate. That seems to solved any and all leaks both internal and external.

[Timothy B.]

Re: 3810 Holley Discrepancy

Gene,

It will turn out nice I'm sure, what hp engine are you installing this carburetor.

If you want to get real fussy remove the IDLE air bleeds on the primary side and tap/install 8-32 x 3/16" brass set screws. The brass set screws can be chucked in a cordless drill and spun while you hold a pin vice with small drill bit. Stock size idle air bleed is .070 so you can experiment up/down .006 either way and play with the idle circuit.

You can do the same with the idle feed restriction (idle jet). Tap with 6-32 x 3/16" deep set screw and make the stock .031 hole smaller/ larger .003 either way.

My feeling is with a street driven Holley, tuning the IDLE circuit will get you the best joy, I did this on my 3810 and you would never notice it was done. I you decide to stay stock you simply install the set screw with the stock size hole.

Have Fun...

[Gene M.]

Re: 3810 Holley Discrepancy

Gene,

It will turn out nice I'm sure, what hp engine are you installing this carburetor.

If you want to get real fussy remove the IDLE air bleeds on the primary side and tap/install 8-32 x 3/16" brass set screws. The brass set screws can be chucked in a cordless drill and spun while you hold a pin vice with small drill bit. Stock size idle air bleed is .070 so you can experiment up/down .006 either way and play with the idle circuit.

You can do the same with the idle feed restriction (idle jet). Tap with 6-32 x 3/16" deep set screw and make the stock .031 hole smaller/ larger .003 either way.

My feeling is with a street driven Holley, tuning the IDLE circuit will get you the best joy, I did this on my 3810 and you would never notice it was done. I you decide to stay stock you simply install the set screw with the stock size hole.

Have Fun...

That was my thinking with the brass set screws if the ,076 meter plate hole don’t work out. This whole thing started due to warpage causing internal leaks. Got that squared away by making every mating surface flat. Right now I got to get some things checked off on the honey do list. Then will be back on the cars.