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Universal Holley carbs choke "partial" flap

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BigBrother-84

Universal Holley carbs choke "partial" flap

Hi Gentlemen!

Some of you already know that I am trying to obtain better cold start with Big Brother.

Last summer I changed the old Holley 4180-C (that came with a replacement 351W 4V engine, around 2010). Installed a universal Holley carb, model 4160-C 600 Polished.

I realized today that the choke flap is never fully closed, contrarily to the old 4180-C:

Winter here can be cold... very cold.

I am wondering if this "never tightly closed" choke flap can result in a too lean mixture for cold starts?

If so, is there replacement flaps available that will completely close the intake?

Jeff / 1984 F350 Crew Cab 4x4/5.8L w351 4V/ T18/ D50 4.10 front/ 8' bed.
Restored 2019-2022.
Nicknamed «Big Brother 1984», due to its soooo-looong shape & nod to George Orwell's 1984 famous novel.

ArdWrknTrk

Re: Universal Holley carbs choke "partial" flap

Administrator

Would you look at that!?!

Holley clipped the flap and did away with staked attachment screws.
They also brought back adjustable float valves!
And they still call this an 0-80457 but I'm not sure of the suffix.

I don't think this should effect starting Jeff.
The vacuum pull-off would crack open the choke plate in any case.
Holley probably did this to head off warranty claims.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Gary Lewis

Re: Universal Holley carbs choke "partial" flap

Administrator

Interesting! But I agree - don't worry about it if the engine starts well, and I bet it will. Can't imagine Holley would do something that would cause starting problems.

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

Rembrant

Re: Universal Holley carbs choke "partial" flap

In reply to this post by BigBrother-84

Interesting. I bought a new 600CFM 4160 a few years ago and didn't notice this, but when I go back and look at the pics, it had the same choke plate. I bought that carb brand new in 2017 or 2018.

1994 F150 4x2 Flareside. 5.0 w/MAF, 4R70W, stock.
1984 F150 4X2 Flareside. Mild 302 w/ 5spd. Sold.
1980 F150 4X4 Flareside. 300i6 w/ 5spd. Sold in 2021.
1980 F100 4X2 Flareside. 351w/2bbl w/NP435. Sold in 1995

AmericanSavage

Re: Universal Holley carbs choke "partial" flap

Rembrant wrote

Interesting. I bought a new 600CFM 4160 a few years ago and didn't notice this, but when I go back and look at the pics, it had the same choke plate. I bought that carb brand new in 2017 or 2018.

That's nice. I have a 500cfm manual choke on mine. I would say more, but I do not want to test Gary's patience.

1980 Ford XLT F350
400 Engine (rebuilt to 406)
Holley 2300 500 CFM manual Choke Carb
Under Restore (1st time)

Gary Lewis

Re: Universal Holley carbs choke "partial" flap

Administrator

Gary's fine, go for it.

Gary, AKA "Gary fellow": Profile

86 1/2 Brutus

Re: Universal Holley carbs choke "partial" flap

I dont think the choke plate is supposed to fully close. I just got my 4160 yesterday from a friend, and its choke plates do not fully close. On the 2150 that the 4160 is going to replace, that one does. I didn't realize this until a few weeks ago. We started the engine and it was running very rough and then it killed. We did the usual procedures when it wouldn't start back up again. check fuel, check spark, scratch head, repeat, cuss and scratch head some more. It was nick who noticed it, he hollered out, George, crank it, i did and it started right up. Turns out the choke plate was completely closed, we just didn't see it, it was cold out, i saw the choke plate closed which it was supposed to, just didnt realize it was all the way shut. Could't really say why this happened. It happened a few more times, but by this time is when we realized it was time for a new carb and intake so i just left it alone.

Nick and George
1986 1/2 F150 XLT Lariat 4X2 300 Six - C6 - 3:08 in a 8.8 - Fully Loaded - 8 Foot Box
Owned since new

Gary Lewis

Re: Universal Holley carbs choke "partial" flap

Administrator

Typically a choke plate shouldn't completely close. There are specs for each application, but something like 1/16" is a good starting point when you have a new-to-you carb.

But you have to be somewhat careful setting the choke as there is slop in the linkage and the choke plate is offset on its shaft. So the vacuum of the engine turning over will take the slop out and open the choke plate a bit and now you may not have the same setting you had before.

My approach when I set a choke is to take the slop out when dialing in the initial 1/16". So it may look like the choke is fully closed if the slop allows the choke to move that far, but when the engine cranks it'll open to spec.

Gary, AKA "Gary fellow": Profile

BigBrother-84

Re: Universal Holley carbs choke "partial" flap

This post was updated on .

Gary, when I discovered this "cut plate" on my new carb, I thought about this little opening gap required when adjusting a "normal" carb, and was wondering if Holley made this "cut plate" to avoid owners to have to deal with, and simply have a full closing flap.
And potentially drop a 1/16" drill bit in the intake while adjusting...

More seriously, I find this cut much wider than the usual 1/16" opening.
That's why I was wondering about a too lean mixture on very cold start conditions.

Jeff / 1984 F350 Crew Cab 4x4/5.8L w351 4V/ T18/ D50 4.10 front/ 8' bed.
Restored 2019-2022.
Nicknamed «Big Brother 1984», due to its soooo-looong shape & nod to George Orwell's 1984 famous novel.

Gary Lewis

Re: Universal Holley carbs choke "partial" flap

Administrator

Jeff - I don’t know what to think about the extra slots. But the proof is in the pudding, meaning let’s see how the truck starts. You can always dial in another notch or two if you think you need more.

Gary, AKA "Gary fellow": Profile