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
Hi Mate, I've fought many battles with dual 94's so here is some suggestions. 1. In my experience, and that of those I've spoken to, dual 94's always run rich at idle for some reason. Mine puffs a little black smoke at idle but performance is great from idle to about 4600. 2. What ignition are you running? Stock? 3. Did you balance the carbs? 4. Have you reduced (turned in) the idle mixture screws? 5. What power valves are you using? Modern Holley ones? If so they are radiused where they meet the bottom of the float bowl. You need to machine them flat in a lathe so they fit. 6. What accelerator pump setting do you have it on?
I think running 51 mains is pretty rich for a 2x2 setup, but it depends on the overall engine. Is the regulator a Spectre unit, a little round one you turn the top to set? They are junk IMO. Try a Holley 12-804, they are about $20.
Running stock rebuilt distributor....no probs before with 1 carb. The PVs are machined for 94s already by Vintage Speed. Isky Jr cam. Holley pressure regulator
Are your accelerator pumps set on the lean setting? 51 jets are around stock for a single carb, might be a bit rich for duals. The stock distributor is made to run with a single carb's ported vacuum and is not the best (ask Bruce Lancaster) I've got a Chevy mechanical advance unit in my flattie, more advance and easier to get parts for in a pinch. When mine's cold, it has a hesitation, but it goes away when warm. You should be able to get the idle down to around 500rpm in neutral when warm. Idle screws should be set between 1 1/4 to 1 1/2 turns out from seated. Flatman
my engine is the early Flatty with the distributor right off the front of the timing cover...the stumble is there hot or cold. Any thoughts on the thing falling flat on its face on accel?
Check to see if the top of the power valve is rubbing on the side of the float bowl. The new valves are real close to the side of the float bowl, and can unseat the valve. You didn't say if you are running a 59 or 8BA. Bob
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