Guys, I put 2 Holley 94s on my Ford Flatty, direct linkage, 051 jets, 4.5 power valves on an Offy intake with the carbs centered over the ports. The carbs are rebuilt with oversize throttle shafts and both are matching 59s. Cheapo electric fuel pump...4 lbs at idle with a mechanical pressure regulator. It fires right up no problem, thumps pretty good at idle (900 rpm is the lowest I can get it with 2 carbs)...problem is it is running so rich at idle it'll just about run ya outta the garage. Thought maybe at first it was a float issue so I dropped them a little...no change. Also, it runs like crap just off idle until you feather the gas and clear it out (I'm thinking maybe power valve prob here?) When I ran it down the road it stumbles off idle, then sets you in the seat, then falls on its face (like maybe the fuel pump ain t keeping up) I wouldn't think two 94s would need all that much fuel. Anybody got any suggestions, or maybe ran into this before, I could sure use some input. Thanks a bunch, Sled <!-- / message -->
Here's a little help... http://www.jalopyjournal.com/forum/showthread.php?t=286574&highlight=holley+links
4 pounds is on the high side, probably not enough to cause this but worth checking into. Try to get it down to 3. Jets and PV would seem fine for a starting point...remember, mains aren't really doing anything below at least 1,000 RPM, and PV's also feed through venturi pull, so feed though those is not your prob. My thought would be to pull those things apart and look at gasket and sealing surfaces on PV's---you probably have a prroblem there caused by 4-barrel PV's not fitting 94 gasket surface at all well. A leak here will give a steady drizzle of uncontrolled gas straight down into manifold...this has nothing to do with PV choice or normal PV delivery. While they are apart, go through idle and off idle circuits end to end... In base, verify that feed holes down and into bore above and below throttles are ok. Upstairs, see that idle jets are normal looking (I can dig up specs for all these orifices, but not tonight!). Pull nozzle bars, verify good gaskets at both ends, and definitely verify that the TINY bleed holes near fronts are open. If idle one is plugged, it will cause enrichment. Set float to lowest spec (biggest measure) or a bit more. Verify check valve under pump squirter...this can feed gas if absent, though not at RPM's where your problem is.
PS...throttle shafts have a surprising amount of influence on total flow. Though they aren't a problem relating to this one, consider some quality time slabbing the shafts with a file...grind eges of file smooth and go at'em. Oversize shafts in a small bore carb are not good, unfortunately.
4 pounds is okay if you have neopreme needle and seat . with engine running look in carb to see if its peeing over if so you have hi float or needle stuck open double check pressure with new gage excelerater pump must be leather type
It would also be a good idea to take the top off the carbs to make sure the notch in the bowl casting isn't keeping the accelerator pumps open. There is an interference on some carbs. Probably not an issue at this point but a couple more things to check: Be sure the carbs have the smaller #71 pump squirters not the larger #69's (stamped on top. #69 squirter is 0.029” and #71 squirter is 0.026”. As a mimimum match sure they match. Make sure that the linkage is set in the lean #1 postion rather than the stock #2 position. Verify that the carbs have the correct accelerator pumps. The pump that comes with most rebuild kits these days is incorrect. Overall length for the 94 is 2.570" to 2.605" (2 9/16”. Some kits are coming through with the shorter 2.492 (2 3/8” long) but nearly identical 885 49-51 Mercury pumps that won't work right (Mac's is one of them). If you look close, the long 94 pump has a short slot and the short Mercury pump has long slot. Set the fuel level a little on the low side. With the airhorn/float assy turned upside down, the bottom of the float should be from 1 3/8" to 1 11/32" from the edge of the flange. Levels from 1939 Holley Service Sheet Form 1030: Ford float 1 3/8”—1 11/32” (1.3750—1.3437). Later specs, 1946 service and fuel manuals, Canadian literature: Ford float 1.353—1.322”. Racer Brown, HRM 11/53, says lower Ford levels by 1/32”-1/16”, .031-.062”.
Here's the full compilation...I looked up all the many sources on float level. Note that original spec from earliest lit was raised by Ford in '40 or so...but almost all like a lower setting. Try out the '39 specs... CG-Ford-Holley AA-1 Float/Fuel Level Information: Levels from 1939 Holley Service Sheet Form 1030: Ford float 1 3/8”—1 11/32” (1.3750—1.3437) Ford fuel 11/16” LZ float 1 5/16”—1 9/32” LZ fuel 5/8” Fuel level will read about 1/16” over actual in gauge tube. Gauge at 3 lbs. fuel pressure input. Later specs, 1946 service and fuel manuals, Canadian literature: Ford float 1.353—1.322” LZ add 1/16” 1947 Service Bulletin subject #9000: All Ford AA’s float 1.322—1.353” LZ float 1.260-1.290” Fuel level 11/16” + 1/32” at bottom of meniscus in gauge. Other information: Recent NAPA-Echlin kit instructions: AA-1, 2100 float 1 11/32”=1.343 2110 (secondary venturi), float 1 15/32 2110 IHC float 1 5/16” Racer Brown, HRM 11/53, says lower Ford levels by 1/32”-1/16”, .031-.062”. 7/27/04
On the parts...we are now officially in an age in which we have to distrust every damn tuneup part we buy. Buy 'em and confidently screw 'em in tuneup parts are disappearing. You can be pretty sure of wrong style PV's, that wrong pump is common, even points and condensers are becoming scarce in useable quality...you have to scrutinize every damn little thing and assume nothing. A good policy on elderly carbs is to keep all the old parts and compare them with new. I never replace non-wearing hardware like jets with new stuff of uncertain origin.
I got my power valves from Charlie Price...they were already modified for the 94s supposedly. Any issues with PVs from Vintage Speed?
Hi Guys, He is using the stock distributor with duals. You need to address the vac retard issues to make this work...assuming it is a 8BA style distributor? Dan
He hasn't said what distributor he has...advance could certainly affect off idle and onward, but not the rich idle. Anyhow...59 carbs can't even connect to a loadamatic, so if this is late distrib, he is running no advance curve at all...Here's a chart of the Loadamatic curve with early carbs: . No advance at all actually wouldn't produce problems like this...I think it would just give poor output followed soon by pverheating.
30 second test of that...warm up car, turn off, kill fuelpump, let it sit a few minutes, then start and get it moving immediately. You'll only last a short time without pump, but you'll know if things have changed!
I need help! I have 6 holley 94's on a 671 blower on a sbc and they are all operational. They were all freshly rebuilt by a "professional 94 rebuilder". I have the fuel pressure set at 2 lbs. and the floats are set at 1 12/32". When I start the engine the four outer carbs drip fuel inside which accumalates on the butterflys and leaks out around the throttle shafts and also drips off of the accelerator pump rods. I have taken the carbs apart and checked the needle and seats for debris and they are all clean. I've also lowered the pressure to 1 lb. and it continues to do the same. I am lost and I'd love any ideas.
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