holley 500 2 barrel. What jets?
 

i have successfully installed the holley 500 two barrel on my 305e but am having trouble jetting it properly. first i tried #72s and it was to rich(fouled the plugs) then i tried #63s and it was too lean(surged after take off) i currently have #66s and the plugs are honey brown like they're supposed to be. the thing is, the exhaust still smells rich. i just adjusted the lifters and tried every combo of idle mixture but it still smells rich and fuel economy is poor (10mpg). I this a poor carb choice? could it be my timing? is this normal? Any insight on this matter would be greatly appreciated. thank you.

Re: holley 500 2 barrel. What jets?
 

rich compared to what? These trucks don't have catalytic converters so they're going to be full force (dont run 'em in the garage :lolflag:)
you should go by what you can measure on the motor and not worry so much about the smell of richness unless she's smoking. Mne smoked like a freight train when i first got her running.
Whats your timing now? It should be 2UDC or 7UDC for manual or auto respectively

Re: holley 500 2 barrel. What jets?
 

ok so its normal if she stinks rich a little. good to know. as for the timing, its an auto trans (th400). how do i set the timing or check it just to make sure its on? i have tried to learn how elsewhere but all the instructionals are done on a 350. if you have the time, could you explain to me what i need and what to do.

p.s. cecilia is a good truck name. mines name is "**** beast". not the most flattering but the name just happened last winter when i got stuck in someones yard trying to turn around in a caldesac. dug a 3 foot hole in the grass, dumped a quarter tank, finally regained traction and screamed "**** YOU **** BEAST" and the name stuck.

Re: holley 500 2 barrel. What jets?
 

anyone out there ever heard of or tried to one of these "progressive" 2 barrel carburetors? its a holley/weber i think.

http://centralmich.craigslist.org/pts/3803469102.html

i guess one throttle plate opens at a time and they are supposed to be better on gas.

i hope im not annoying everyone cuz all i ever talk about is getting better gas mileage but dang... is 15 mpg to much to ask from these ol' thangs?

Re: holley 500 2 barrel. What jets?
 

Thanks for the name compliment I just saw it :P

No, not getting fed up with the mileage talk. Everyone wants to save a few bucks. Just be sure not to spend 10x as much as you'll save trying to do it lol.

I haven't tried one of those carbs but I have read that most mileage improvements are by changing the rear end gears so that you get faster umph with less RPMs. Of course it takes it off the bottom end though so if you use her as a truck hauling stuff or pulling bushes and trailers you might regret it a bit.

Re: holley 500 2 barrel. What jets?
 

I have a 351E & put the 500 Holley on mine last year. They are right,you don't want to run it in the garage, mine seems rich also, but it sure runs nice. Had it on the hi-way the other day & it cruises great @ 60-65-MPH. I put mine on out of the box. Never adjusted it, I drive it. Besides electronic ignition 2 best things I ever did to the motor. Donrm 1966 GMC 8' fleetside p.s. p.b. &a/c Cinti oh P/S I contacted Holley they told me a 500 was too big! I listened to other
members. Tried & tested is the rule I follow. Thanks to the club.

Re: holley 500 2 barrel. What jets?
 

The Holley/Weber progressive carburetor was used in the 70's by Ford in there 2000cc and 2300cc pinto 4 cylinder engine, I think GM also used it on the Chevrolet Vega and Pontiac Astre. It's questionable how a carb like this would work on an engine twice the size of what it was intended for.

Re: holley 500 2 barrel. What jets?
 

Holly 500's normally have a 1/8 inch or so hole in each throttle plate.
This is to allow the plates to be at the proper position at idle in relation to the idle mixture slots on a 350 to 400 inch motor that idles at 750 or 800 RPM.
You may want to try sealing the holes with epoxy. This will allow the plates to be open further, and may improve mixture at idle. I am guessing that it is now OK going down the road, just at idle you notice it being rich.

Re: holley 500 2 barrel. What jets?
 

Oh on the MPG thing, if anyone has been able to get better than 12, please share the secret.

Re: holley 500 2 barrel. What jets?
 

I just installed a Holley 500 in my 65 and found that right out of the box my truck ran better than ever. I went from a top speed of 63 (GPS) with my Stromberg to 75 mph. I only ran this fast for a short time but all in all it runs great.

Re: holley 500 2 barrel. What jets?
 

yeah the holley is a huge improvement over that dog crap asthmatic fuel dumping stromberg. with the stromberg i had to keep the pedal to floor to do 55 and the engine sounded like it was going to explode! with the holley 500 i do a relaxed 65 all day at half throtle. she'll do 75 but she dont like it (friggen 4:10s). i get 14mpg for about 4 gallons right after i change my plugs and oil, then it goes to 12 for about a week then back to the painfull 7-9. i cant keep those plugs clean! ive re jetted, re power valved, replaced points, condenser, rotor, cap and wires. right now im in the process of doing the timing and looking into a hotter coil. somthings gotta give eh... oh im gonna try that throttle plate thing too. thanks guys, as always any input is awesome and this site rules.
currently running: # 67 jets, r45xl8 acdelco plugs(suposed to be hotter) at .035. stock coil, unknown squirter nozzle size but i'll check it tomorrow if my wife lets me.

Re: holley 500 2 barrel. What jets?
 

I will be doing the 500 swap as early as... tomorrow! :champagne:
I have never messed with one but I know the 4bbls pretty good and it is half of one...

Have you messed with the accelerator pump cam at all? If it is running good with no flat spots maybe you shouldn't!
I really enjoy tuning and experimenting with this stuff. My buddy has a wideband and it is so handy at the point you are at. If I get anywhere with it anytime soon I will share whatever we come up with.
He is so busy it might not happen soon though.

Re: holley 500 2 barrel. What jets?
 

Talking about a hotter coil? At this point you should just do away with the stock points ignition and upgrade to Electronic Ignition whether a GM HEI or a Pertronix with an Ignitor coil will enhance your Holley 500 conversion and will keep those plugs cleaner.

Re: holley 500 2 barrel. What jets?
 

Does anyone know the base gasket part # for this carb? I know the closest parts store is gonna need an application or part# and I don't know what these carbs were original equipment on.

Re: holley 500 2 barrel. What jets?
 

The vehicles that used the Holley 500cfm carb were the late 60's and very early 70's Mopar 440 "Six Pack " Super Bee, possibly the Demon Duster Six Packs as well. Either way it was a Chrysler application.

Re: holley 500 2 barrel. What jets?
 

you should be able to use the same base gasket as most ford two barrels.

Re: holley 500 2 barrel. What jets?
 

The Ford 2bbl's have smaller throttle plates than the Holley 500 so the gasket may not work, stick with the Chrysler 440 Six pack application or the 427 Corvette which used 3 Holley 500 carbs back in 1966.

Re: holley 500 2 barrel. What jets?
 

Installed mine today. It was on another 305 V6 recently so I just slapped it on.

BIG IMPROVEMENT!

probably still room for improvement...

I can't wait!:yeeuh:

Re: holley 500 2 barrel. What jets?
 

Good to know! I had the ones that came with the adapter. I will need more soon when I clean and paint everything.

Re: holley 500 2 barrel. What jets?
 

But remember they run at half the revs. Somebody needs to try them.:goodluck:

Re: holley 500 2 barrel. What jets?
 

I put the 500 Holley on my 351e a year ago. I contacted Holley, they told me it was too BIG for the 351? I never changed the jets & don't plan on it. Great response when given. Donrm Cinti, Oh 1966 GMC 8' fleetside.