Technical 4x2 setup problems

I have a Offenhauser pacesetter 4x2 intake with holley 94 carbs on a Chevy 327 fresh build, mild flat tappet cam, I was wondering what jets would be best , the carbs currently have #47 jets. Also what is a good initial timing setting? I had it running, but it falls flat when I try to accelerate. Thanks

 

did you sync them first??? I'd go all in @ 32 is it all four live or progressive... when you look in the carb do you see it squirt??? is there throttle idle screws on all 4 caubs... if so back off all the screws till there is a gap.... use a piece of paper and turn the screws in till you feel it touch the paper... do all 4 carbs this way.. then go back and turn them all 1 turn in... from here on out what ever you do to one do exact to the other 3... turn all the idle mix screws in till seated.. then out 2 turns.. should start and idle high.... next turn each carb throttle screw out 1/4 turn.. but make sure you do all... if it dies... go back and turn the screws in 1/8 and start it.. if now it idles turn each mixture screw in 1/4... listen for it to start to stumble
but what ever you do to the first... do all 4... even if it dies on you.. if it does die... go back and turn all four out 1/8 .. depending on what distributor ... you need to know how much advance it has... I have a back to Zero , makes it easy... but you can do the same with out... once its locked in watch to to see the timing mark move to advance....

 

another most important thing is a vacuum gauge... make sure you don't have vacuum leaks...and it helps when doing mixture screws... I have a unison that I fine tune with but you shoud be able to get real close

if it lean pops, make sure the accelerator pumps are squirting

 

1 - Are ALL four carburetors open the SAME amount at idle ?
If not, take them off the manifold and use a "small" drill bit to adjust them properly.

2 - Then, have you synchronized them with the engine hot and running ?
If not, synchronize them properly.

3 - Do ALL four have the same accelerator pump adjustment ?
If not, adjust / fix them properly.

4 - Is the linkage adjusted to open all four carburetors the same amount at the same time ?
If not, adjust them properly.

5 - What is the coloring of the spark plugs now ?

6 - The ignition timing and the carburetor count have nothing to do with each other !
36 degrees (try 8 degrees before TDC) total is a good place to start. Listen for any pinging, adjust accordingly.

Mike

 

why use a drill???? the screws only have to turn a few turns... also the color of plugs tell you nothing.... also... you can just read the timing strap on the plug once its running to see where the timing is...

 

don't do nothing to the jets till it idles right with the most vacuum... the jets do nothing at Idle... and the plugs won't tell much if they been running around...to read the mixture at mid throttle first you need to do it with new plugs,,,, need to run it at mid throttle and shut it off coast to a stop and pull the plugs and read them.... I do just one easy to get to and see how close it is....

but to start..... after the idle is right.... roll on the throttle, is it shooting ducks or rabbits... as in popping thru the carb... lean.... through the exhaust fat.... if its shooting ducks make sure the carbs are all getting an accelerator squirt... they need the squirt to roll over from idle circuit to main circuit

 

to read plugs,... if you know how... you look for the fire ring.... the ol.. you want a milk shake color is wrong.... you have to look inside the plug to see if it's lean or fat




as you can see from this plug, it's way too fat...

 

next, look at the strap.... needs more timing...

 

Nice setup, keep at it, you'll get there.
Meanwhile I gotta ask, what's in the next bay?

 

Fixed the picture.....
Nice heads.....

 

the pic makes it look like the dist. is inside the car.... but once bitten twice shy... that fuel line block right above the dist looks a little spooky to me...

 

everything you need to know about holley 94's but were afraid to ask.......

Links to Holley 94 Technical info | The H.A.M.B. (jalopyjournal.com)

 

For anybody running more than one Stromberg 97 or Holley 94 (and the various versions of each), do yourself a favor and purchase a Uni-Syn - it will enable you to synchronize the air-flow/vacuum in the carbs. If they aren't flowing the same amount of air (by reading the vacuum for each), you'll never get the tune correct for all cylinders as the amount of air/fuel flowing through each will be different. I bought one 50 years ago and use it on every multi-carb 2 barrel setup.

If the engine is falling flat when you initially attempt to hard accelerate, this is usually representative of it going lean when all the air starts flowing. Usually this is cured by making sure the accel pumps are working and/or adjusting how much "squirt" is associated with each. You probably need more fuel when the initial volume of air starts to flow. The main jets don't usually cause this - they're more associated with overall rich/lean conditions throughout the RPM range.

Here is a little cheat sheet - see item #3:

Holley 94, 2100, 2110, AA-1 Carburetor Adjustments (carburetor-parts.com)

Where to purchase a Uni-Syn

Edelbrock 4025: Uni-Syn "A" for 1 and 2 Barrel Carburetors - JEGS