Holley 94 - jets and PV

TDS

TDS

Member
Hi
I got a single Holley 94 setup on my completly stock 1935 221 cui flathead. I know its not the correct carburator for my car but...

Im running rich at idle and speed.

What size main jets should I use/try?
Which PV size should I use/try?
 
Stock 50 or 51 jets and a 7.5 power valve should get 'er dun.

That said, many, many things will make a 94 run rich.

Poor needle jet seat. (Use older steel tipped ones)
Spring in fuel pump too strong (mech pump)
Pump pressure too high (electric pump)
float ruptured.
Float setting too high.
Power valve ruptured.
Power valve incorrect shape at seat.
Power valve gasket incorrect.
Poor sealing of power valve vacuum chamber (flatness of housing faces)

Give all of those some attention and you should be good to go. There might be something I have forgotten, but that's all I can think of off the top of my head.

You know when all is right when you can attain a successful hot restart with just the slightest stab on the starter.
 
PV and jets don't really enter in at idle...except if PV leaks at its seat or is ruptured, letting gas drain in directly.
I suggest as an easy first step give it a short drive without air cleaner. Many troubles start their, with both oil and dry types capable of plugging up with accumulated stuff on mesh.
Then remove carb, fill up bowl via the bowl vent, and set it on a paper towel for a while...this will reveal PV leak.
Also check nozzle bars...each has two tiny air bleeds that are often overlooked in cleanup and rebuild.
Many currently sold PV's are from 4150 type four barrels and have a seat/gsaket surface that does not fit on a 94.
 
Good advice from Mart and Bruce Lancaster. Don't go changing main jet sizes until you check out what they said. Very simple carb to work on.

Sal
 
Great advice guys! Which now begs the question; Who sells the "Right" parts?
Power valve, accelerator pump, Rebuild kit etc.
How does one identify the various models?,
and where do I find good rebuild info?
(I am being lazy, but with the above info all in one thread, it will be a good one to subscribe to, for anyone wanting 94 info)
Thank you in advance!
 
Hi​
I checked my main jets - 51 og PV is 7.5.​
I rebuild the carb last year but the engine broke down shortly after.​
Engine i s back in and I guess I better go trough the carb again.​
I'm from Denmark - does someone have a link to a online store where I can find the right Holley 94 parts - thanks.​
At idle a light white mist of unburt gas and at acceleration first a dark blue mist turning to a light white mist.​
:)​
 
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I'm using a stock mehanical pump.
I dont like to work with wireing so ............
 
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those jets and PV are correct for the carb. is the PV new? the new style don't seat properly in the carbs and leak - could that be your issue?
 
Bruce Lancaster said:
PV and jets don't really enter in at idle...except if PV leaks at its seat or is ruptured, letting gas drain in directly.
I suggest as an easy first step give it a short drive without air cleaner. Many troubles start their, with both oil and dry types capable of plugging up with accumulated stuff on mesh.
Then remove carb, fill up bowl via the bowl vent, and set it on a paper towel for a while...this will reveal PV leak.
Also check nozzle bars...each has two tiny air bleeds that are often overlooked in cleanup and rebuild.
Many currently sold PV's are from 4150 type four barrels and have a seat/gasket surface that does not fit on a 94.
Click to expand...
I essentially stopped having 94 problems when I did this. I also agree with the last statement about power valves.
 
Charlie N.Y. on this site has the correct "machined" parts for a good fit. Get his info from the "Community" section of this site and PM him with your carb issue.
 
For a 94, Where can I buy a "GROSS NEEDLE SEAT". This is the needle/seat using small balls, no needle?
 
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