4 holley 81's what jetting and power valves

[4tford]

Back to this intake now that I have it in my hands. Yes carbs are HOLLEY 81's. on a 276 flatty for the street what would be the best jetting and power valves to use. No idea what is inside yet. Thanks Bill

[ken ct]

I would try all .041 MJ [Stock is .043] PV #3.5 in all. May try pump link in rear hole [not in middle holes] gives a smaller shot. This going to be a crap shoot all around.. Best of luck.I may have all you need?? ken ct.

[rotorwrench]

Four carbs is a lot of fuel delivery for a street motor even if they are all 81s. A person can use progressive linkage on three carbs but I don't know if anyone currently makes one for four.

[Charlie ny]

4t,
With straight linkage....only way to go in my opinion with 4x2's .....your vac
signal will be real low. At the risk of doubting looks from JWL and Ken I'd block the
PV's and tune with main jets. '94's get edgy in a setup like this. My focus is not
theory it is street reliability. EX. my best success with 3x2 94's is to block the end
carb PV's and retain the PV in the center carb only.
I absolutely feel this setup will be happiest with Stromberg 81's.
Charlie ny

[lonewolf]

i think charlie ny nailed it.

do the air fuel mixtures screws hit the intake on the rear carb?

maybe sell the 92's and put on 97's thats what i did still have some 92's if anyone is interested

[uncle max]

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Knock knock...

Originally Posted by Charlie ny

4t,
With straight linkage....only way to go in my opinion with 4x2's .....your vac
signal will be real low. At the risk of doubting looks from JWL and Ken I'd block the
PV's and tune with main jets. '94's get edgy in a setup like this. My focus is not
theory it is street reliability. EX. my best success with 3x2 94's is to block the end
carb PV's and retain the PV in the center carb only.
I absolutely feel this setup will be happiest with Stromberg 81's.
Charlie ny

[ken ct]

Everybodys got there own opinions LOL . Go for it you can always change it or them.I also have dummy PV's and bigger jets in the .044 to .050 range You will need bigger than stock jets if you blockoff the PV's. ken ct omo.

[jim1932]

I guess I have a lot to learn.... Holley made 81's too?

[Vergil]

I like to tune with a AFR meter and O2 sensor, It will let you know what is happening as you drive, rich or lean and at idle. Under a load you can see if your power valves open to early or late. I think one problem when running 4x2's is when you crack open the throttle to start from a stop, very little throttle movement lets in a lot of air at low rpm. I have my throttle foot pedal set up so there is very little linkage movement until the pedal moves about half way to the floor and then it opens fast. A Unisync is a must for me to sync all the carbs at idle.

Vergil

[Walt Dupont--Me.]

While we are on the subject, you all know it's hard to get you fingers in between those carbs to ajust the idel screws. I used to have tool that was long and a right angel on the bottom with a screw driver thingy. You could turn the handle to ajust the carb. Does anyone know where I could get one of those. I tried Snap On, no luck. Walt

[Vergil]

Something like this Walt ... http://www.amazon.com/Milwaukee-48-3...690023-1252563

[jdl]

Originally Posted by Walt Dupont--Me.

While we are on the subject, you all know it's hard to get you fingers in between those carbs to ajust the idel screws. I used to have tool that was long and a right angel on the bottom with a screw driver thingy. You could turn the handle to ajust the carb. Does anyone know where I could get one of those. I tried Snap On, no luck. Walt

Walt, a flexible chevy point adjusting tool might work for you ( the kind you can adjust through the dist cap window) ebay has some, here is a example....


http://www.ebay.com/itm/NEW-GREAT-NE...r#ht_750wt_679

[Charlie ny]

Verg,
You got it....zilch for vac off idle and the PV's open or at least crack open a bit. With Strombergs the power circuit is mechanical with just bit of hydraulic tingle. OMO.
Charlie ny

[Vergil]

Originally Posted by Charlie ny

Verg,
You got it....zilch for vac off idle and the PV's open or at least crack open a bit. With Strombergs the power circuit is mechanical with just bit of hydraulic tingle. OMO.
Charlie ny

Charlie you are correct on the Stromberg power valve .... my bad, had 94's in my mind ... thanks for the nudge ...

[Walt Dupont--Me.]

Originally Posted by Vergil

Something like this Walt ... http://www.amazon.com/Milwaukee-48-3...690023-1252563

Vergil. I think that power tool would be a little rugged for adjusting idle air screws. I have one of those flexable ones but with 4 carbs you still cain't keep it in the slot of the screws. The one I used to have years ago was about a foot long and rigged with a 90 degree on the end with a little cup on the end that went over the head of the screw and ingaged in the slot in the screw. You turn the handle of the tool. Walt

[4tford]

Ok, It seems as nice as these carbs are they are wrong for the application. Would they be better used on a dual setup or am I wasting a sort of rare carb. What should I do with them.

[Walt Dupont--Me.]

It would be nice to know what else is in the engine, or is it stock. I believe those carbs are Holley 92 The 92 was made for the 60hp 136ci engine. I've never had one but I know there smaller venture than the 94's. I see no reason they cain't be set up with direct linkage. I don't know what the jet size is stock but I'd start out with 2 steps smaller, and probably 4.5 power valves. Walt

[4tford]

at the moment there is no engine