HELP with Holley 94's on a Blower!!!

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" and the power valve holes have been plugged. When I start the engine the four outer carbs drip fuel inside from the bar 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. It also continues to drip after the engine is shut off. I am lost and I'd love any ideas.
Thanks, Mark
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My first guess is Floats. Take em out and submerge them in gasoline, if they take on fuel there you go.

 

i had the same deal with two of the three 94s, on mine turned out the floats had cracks in them if you shooked them you could hear the gas inside....

 

Check floats as above and also ensure the clearnace around throttle shafts isnt too excessive.

Rat

 

And what does the "professional 94 rebuilder" say?

 

Lower the floats, fuel level is a tad high.

 

Thanks for the replies. I checked the floats and they seem to be ok, no fuel inside. As indicated they are currently set at 1 12/32" what should they be? The "professional rebuilder" who has never had a problem in 40 years says the fuel pressure is too high, but I had it set at 2 lbs and lowered it to 1 lb with no effect. Should the float bowl be vented?

 

Mate,

Do you have the dial type fuel pressure regulator where you can turn the dial and it turns up or down the fuel pressure? If so, double check to make sure its connected the right way (ie. inlet and outlet) as you can only run them one way. Getting it wrong causes fuel to piss out of exactly where if is for you.

Danny

 

Yeah check that as above but those regs are a POS anyways.....they fdont always hold pressure and they creep badly. POS IMO esp on ablown engine....ya dont want any leanouts up top now do ya?

Rat

 

Wow, 2psi!!! I can't tell you anything about those carbs but can tell you any racer will shit a brick if you mention running 2psi fuel pressure and a 6/71 blower. I would not want to be your piston tops at the thousand foot mark.

You may be fighting a gauge range issue. Anything over 12psi gauge sweep is not appropriate to fine tune that low.

Cool truck, good luck

 

All 94 and 97 carbs will not withstand anything more than 2-1/2 lbs before they start leaking.
These carbs are 50/60 years old and were never designed to run at high pressures.

My Demon blower carb will run at 7psi and be just fine for my 141 Wieand Blower on top my flathead..........................

 

I have blasted down the Strip on 6psi. w/ my Six-Two setup last year w/ no problems.....I do not recommend that thou....you have to watch it like a hawk.....but can be done in a racing enviroment........I Race w/ on average 3 1/2 to 4 psi...........but thats w/ some of the tricks I have come up with and am still testing......you learn by trial and error....Littleman

 

Don't think fuel pressure, long as you have positive pres at WOT you're ok. The problem is at idle. The float is too high, the level might be ok on the work bench but in the car there are other things coming into play like whether the engine is level etcetc. Lower the float a 1/16 or so and the problem will disappear. Fuel level being too high is the only way that fuel will continue to dribble out of the booster when the engine is shut off. If the float is damaged/cracked it'll be waterlogged and fuel will erupt thru the vent at 2psi or whatever your pressure is set at.

 

When you say your running 2 PSI is that reading a pressure gauge or is that what you've dailed your regulator down too? Some regualtors can not take high pressures and have little or no effect on lowering the actual fuel pressure.

I run four 97's and my fuel pump was flooding my carbs out big time. You may want to change to a low pressure fuel pump. Made a world of difference on my setup.

 

Mate,

I thought the same - seriously, having the regulator backwards did exactly that - floats were set perfectly and functioning but it would HOSE fuel out at shut down. Like literally piss it out in a stream.

Danny

 

Thanks for all the responses. I am using a new holley low pressure regulator and I have a low pressure guage mounted in the fuel log so I am confident the pressure readings are correct. I can only assume that pressure is not the issue and I know the floates are in good shape and not filling with fuel. The floates are set at 1 12/32 but I did lower one allot to see if it made a difference. I can't remember the height at the time but it continued to leak so I re-adjusted it to 1 12/32". This weekend I will lower them more to I guess 1 14/32-15/32" what do ya think? And...how and why is it dripping fuel off the bottom of the accelerator pump rod?

 

OK, I took all six carbs apart and reset the float level on the four outer to 1 15/32" and the two center to 1 14/32. I blew out the needle and seats, reassembled and they continued to drip from the spray bars. Now, the needle and seats that were used I have never seen before, they have a "needle" which is not a needle it is flat on the end and seals against a piece of rubber not the standard pointed needle and seat that is typically used. Are these any good or could this be the problem and again I have adjusted the fuel pressure from 2 lbs to 1 lb to less than 1 but nothing has resolved the problem.

 

I hope you figure out your problem.But what ever you do do not let the motor lean out very bad .My last 2 cents

 

Hey, I'm new on here and usually read and never post but it sounds like your needle/seat assemblies are bad. You've confirmed the fuel pressure isn't too high and that your gauge is reading what the actual fuel pressure is. You've checked the floats for holes and correct setting. I'd say your needle and seat assemblies are bad. When you say they're "flat on the end and seals against a piece of rubber", do you mean it has a rubber tip for a needle? It's possible your carb guy re-used old ones that are worn out or something. I dunno what else would cause fuel to drip in like that unless fuel was flowing past the needle, which would seem like the pressure was too high like you describe.

 

Morning Coast, you must have a real conumdrum. You can't be that far from me and i can rig a pressure test so that we can work on the carbs right on the bench if you want to come over. I use a solvent that is similiar specific gravity to gasoline but won't hurt the seals and we can connect the carb to a fuel system and figure out exactly the the problem. Give me a shout, oj

 

you are using the needle and seat like this right it has the little rubber disc under the needle, thats a roto type set, i didnt like them in my 3x2 set up, and went to the stock ones like works great no leaks, not saying the roto type are not any good, just leaked for me...

 

Coast, try switching the two center carbs (that don't leak) with two that do. That might verify the condition of the carbs. Making it an airflow through the blower problem. Are you using progressive linkage?

 

See them gaskets in flathead31coupe"s pic. Are they there?

If you can get "Grosse Jets" the glass ball ones for those carbs, you could try them, I used to use them in racing carbs and they worked under tough conditions.

I would also keep lowering the floats, make sure you are Lowering the fuel level, not raising it. 1/8 to 3/16 seems better, even 1/4. Then if you lean it out that way you can main jet a little more.

I do believe the density of our new blends is lower than real gas used to be. That makes the floats sink further in the fluid. So the float need to shut off at a lower setting to compensate the fuel level.

Also the pressure affects the level, some kind of physics involved here. If you get the float level really low, you can actually bring it up by increasing fuel pressure to balance it. And moving the level around can help you fine tune the jetting once you are close.

 

Hi Guys thanks for the replies. You are right flathead31coupe I have the roto type. I have never seen these before so this is my first experiance with them and I can't help but think they are the problem. However they are new, clean and appear to hold pressure when I blow into the fuel inlet but at this point I think that I'll try the standard needle and seat to see what happens and then play with the float level. I will let you know the results.

 

Hi OJ, Thanks for the offer, I know exactly where Berryville is and the next time I'm headed in your direction I'll see if you are available and we can hook up. Thanks again.

 

Jump on that offer

 

OK, here's where we are...today I replaced two of the "roto" type needle and seats with two used "old style" needle and seats from a couple Holley 94's that I had and those two stopped dripping. After all of the changes that I've made I can old assume that this is the problem. I have emailed the "Holley 94 EXPERT" that I purchased these from to send me six new "old style" needle and seats. I'll keep you abreast...

 

I am/was having a similar problem with two 94s on a blown flathead , checked fuel pressure @2lb still leaking out shafts etc. rechecked PV they seemed spot on for no leaks. Rechecked fuel pressure with a different gauge and it showed 4lb so cranked it back to 2lb and this has improved it considerably but still think I need to lower PV from5.5 to 3.5 . running @ 13 in of vaccum at idle. So be sure you gauge is accurate.

 

I need to lower PV from5.5 to 3.5 . running @ 13 in of vaccum

Why would that have any effect?

 

I had a simular problem with the "new" rubber tipped needles on the 97's on my flathead. Changed to the old style, problem solved. Good luck!