Holley Ultra Xp- a " heads up " .

Just finished a RB 511 and went to Dyno .

First a big thanks to Dwayne and Andy F for all the help/ advice / work.

Got to Dyno - Holley 950 Ultra XP.

Felt it was over jetted but, let it ride - let Dyno tell us.

Carb was " all over the place" .

Had to keep adding jet , espescially drivers side- jet changes kept making " less than expected changes" - like your chasing a vacuum leak.

No leaks could be found.

Ended up at 106 on drivers side- 101 on passenger- that's crazy for a bb mopar at this level.
Dyno operator stated- I just went through this- carb is bad.
Found three boosters loose.

Long story short: came home, researched, called some carb guys- these carbs have a known issue- being drilled poorly .
You can put a light through meter plate body and see light around/ behind the boosters.

If I had " asphalt tuned " rather than Dyno- likely hurt motor .

If your buying one- please have it checked out before running it.

Just my take.

But......but......but........ they're all wet flow tested for quality assurance

so you purchased a brand new carb core....... not in the script!

Yep- I'm an idiot .
Grin

And now they own Quick fuel.

I've had several in my hands and they were all fine maybe just a mon or fri crew assembly..........However NOT surprised at all w/QC on the whole damn planet.............

Holly quality has really gone downhill.
After the problems with my Truck Avenger carb, I won't put a carb on out of the box. When I get a new carb, it gets dis-assembled and inspected/cleaned then re-assembled.
The Truck Avenger had metal in the metering block well behind the jets.

I had a 950 Ultra that worked fine out of the box. I sent it to Mark and had it changed over to annular boosters and then it worked really well. Then I sold it to Brad but I don't think he has run it yet.

Rusty has pm'd me a more detailed chronicle of how the dyno session progressed and where they ended up for jetting...... At which point I told him there was likely an issue with the carb.

He made some calls to see what he could find out, and from what I understand, it was revealed that this isn't an isolated incident with these carbs.

I guess the best thing to be done here is, take this as a word of caution.
If it seems the carb is unresponsive to jet changes, or requires oddball stagger jetting, or if there is any looseness to the boosters...... It probably needs to be sent back.

If I purchased a carb w/these issues it would for sure go back and sukz for those that count on a good piece for the good money spent........

Really disappointing. Especially with a carb that is touted as their top-dog 4150. I'd send it back for sure, and have a conversation with someone at Holley. Big company likely with people on an assembly line that don't give a sh!t about their job.... sad. I recently purchased an HP 1000 annular direct from Holley. It has worked great out of the box with only idle mixture adjustments and a main-jet adjustment.

To be fair, The 1,000 cfm HP carb I bought 20+ years ago worked really good out of the box. The 670 Truck avenger, I bought about 8 years ago, and the most recent Holley I bought (new) was the 770 cfm Ultra street avenger about 5 years ago. It checked out OK (no debris in the passages.) In my case, both avenger carbs had very lean idle circuits that needed to be have the idle restriction enlarged.
Other than the QF-1000 E-85 carb on the Charger, everything else has been getting converted to EFI.

Last item on the long list of features for this carb on the Holley website:



I guess it depends on how you interpret that statement....... I mean........ It did "run".

If this one was wet flowed, it was with far too much beer.
It's a mess- there are three here locally going back.

Just don't run them without checking - looking at a/f ratios.

I posted this thread because I don't want anyone to hurt a motor .

If I hadn't gone to Dyno- I would likely be pulling this one back down .

Carb was pretty bad and, in such a way as it's not readily apparent.

When your lean- one usually doesn't think- hey, lets jet up 6 sizes on one side and 4 on the other- that should do it !
Grin

Here's a "wet flowed" story...... Not from Holley though.

This was 20 years ago.
Customer buys a $1400(in 1997) BG "pro stock" prepared dominator for his 540bbc.

Makes pretty good power, but is wicked lean, and is pretty unresponsive to jet changes, especially on the rear.

Put one of my carbs on, plenty rich enough, makes less power...... But it's a 1050 instead of 1150.

Try swapping rear metering block from my carb to new one...... Marginally more fuel flow, a little less power.

Try another reworked 1150, plenty rich enough...... Less power.

Several calls to BG...... We're told the dyno is reading fuel flow wrong....... Can't be the carb, it's custom built and wet flow tested.

So, we're second guessing ourselves a bit. Afterall, the new carb did make good power.

Well, before we got it figured out, it burns up 3 pistons.

I guess the dyno wasn't lying about the fuel flow.

I pull carb all apart....... One of the rear booster stake tubes had gotten the end of it folded over when it was installed, so that barrel had basically zero fuel flow.

There was a pretty long pause on the other end of the phone line when we told them what we found, and what had happened as a result.

Never did get a good explanation as to how that wasnt caught during the wet flow testing.

Man! Bummer for sure. I don't know that I've ever taken a carb out of the box and bolted it on without at least inspecting the bowls and setting some initial float levels, making sure the jets are what they say they are, gaskets right and everything tightened down like I want it. I bought a set of Demon TR carbs for my boat and they were basically falling apart out of the box as nothing was tightened down.

Ultra Xp 950 e85 out of box it was perfect!
No complaints except $$$$$$

Carbs are like girls they all look good when new--but it takes a test drive to determine if it is going to work out--
Over the years had some really great ones and some real trouble ( carbs and girls)
I sent a set of new six pack carbs out for the money no object build before dropping them on a new big inch custom--fired it up on the dyno--sounded awful--just could not figure what was happening first couple minutes then dyno ran out of fuel--turns out there were NO jets in the carbs ( all three were set up for jets) and all that fuel was in the crankcase--
But then bought an AED 750 HO out of the box changed jetting one time and bracket raced it for many years --won a lot of rounds never ever touched it so...

wet flow story #2......

We were a BG WD........they had a pretty good program for dealers to be able to match Summit and Jegs on the price of their carbs, which we just couldn't do with Holleys at that time.

The King Demons are introduced........and I have to have one.
This is probably a couple years after the pro stock carb fiasco.
I buy a 1090 non-removable sleeve version.

We have another, milder 540bbc on the dyno and I'm anxious to try it out.
The engine owner is fine with it. He had just bought a new HP1250 dominator, which is kinda rich, so we jet it down and get it sorted out.
I had gone through another 1050 for someone else, just wanted to make sure it was good to go....... bolt it on, make a pull......all good.
Both of those carbs run just fine. Start good, idle good, decent throttle response, good fuel curve.

Bolt the new king demon on.......doesn't start great......and after its running, and the floats are set.......start messing with the mixture screws.....one doesn't seem to do anything.
The motor just hunts around at idle. Throttle response is poor.
I try and make a half pull.........carb is way lean.....abort the run.
I just take it off.

Take carb apart......there is a machining defect at the top of one of the metering blocks where the idle tube is pressed in.......and there's a bunch of clear epoxy all over it.
Needless to say I'm not impressed.
I remove the idle tube only to find that a bunch of the epoxy ran down in where the fuel flows and plugged it up. Well, that explains the non-working mixture screw.

Since I had aldready been "schooled" on the booster stake tube thing...... I investgate that only to discover that one of them is folded over almost as bad as the one in the pro stock carb, and another one is slightly deformed so it's about 1/2 blocked.

Call BG, they say send it back. I say......no thanks.......just send me a new metering block and a set of stake tubes and I'll fix it myself......... which I did.........and then it worked "okay".

I got it to where it did everything well enough, but no better than an old school 1050 Holley I had.......so I sold it to a guy with an 800hp BBF.

Well, at least I know I'm not alone.

I have had great Holley's, Carters and, some that were " off " .

I have never had one , of anything- with these type issues , espescially at what's considered " this level " of Carb .

Manufacturing problems can happen to anyone and, you mass produce a popular products- things are going to happen from time to time- no one and nothing is perfect.
That's why you open them up and check things out.

In the case of these- there are a lot of them bad and, as Dwayne has mentioned- these are supposed to be " wet flowed" for final QC .

No way these carbs pass a flow test- ain't possible .

It appears Holley is going to make it right .
You can bet it's going to get tested/ tweaked before bolted on.

maybe wet flowed means they are dunked in a vat of alcohol, then rinsed off ? no excuse for finding particles or shavings in a purchased part except for lazy workers. before i retired, i fought with the guys that worked for me that their job was to drill and tap a 1/8"NPT with a 1/16" through hole in an iron regulator body. super simple job, and it required a simple blast with air to clear the chips from the hole when completed. that blast of air was important, because if not done, the iron chips would compact in the hole after running through the washing equipment, rendering the small through hole useless. and after sitting on the shelf awaiting assembly a day later, those leftover iron chips turned into a huge deal to remove ! upon flow testing, the failed regulators were returned to my department to be disassembled and inspected to see why they failed. almost all that failed had iron chips packed into the previously mentioned drilled and tapped hole. caused again, by lazy assemblers that couldn't take a second and look into the hole to see if it was clear. all started by workers [unfortunately mine] that were lazy and did not do a simple procedure that was REQUIRED when the work was done initially. i even paid close attention by being present when the work was being done [and it was done perfectly then], but when i left, back to being lazy ! it is surprising i have any hair left.... this tale might not be carb related, but just illustrates similar machining irregularities happen in other products as well.