Holley Hp CFM flows inflated

Holley is misrepresenting their HP carb flows, a HP 950 is really a

830, a HP1000 is about a 870 if measured the same vac as a 47-- series. The industry standard for cfm ratings was 1.5"Hg vac for a 4 barrel. holley decided to follow the deciptive lead of it's competitors and use 28"wc which is 2.06" hg. Holly has all their carbs listed with flow spects. They make no distinction between a HP type and a older 4781 type. Unless you actually flow a carb, with holley's listings, you can't tell what flow it may be since the listed flows of the 4 barrels are not made with the same test standard. Their all listed together by flow ratings. I'm just for the truth in advertising, if holley actually told the test vac for carbs it would be better, Esp if they use different test spects for different 4 brl carbs. It looks like Holley uses a 1.5"HG vacuum standard for the 47_ _ series carbs and for the HP series they use 2.06"hg vacuum test standard. The result is a false comparison between the two carbs. I got tricked and many others will be also. Spread the word about this .

The HP950 has a 1 3/4 base plate and a 1 3/8 venturi. A older 850 has a 1 3/4 base with a 1 9/16 venturi A HP830 has a 1 11/16 base and a 1 9/16 venturi

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Reply to
cd1048
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From the article: "Holley decided to rate their new line of "HP" carbs like their competition does, with inflated CFM figures. They had to. Otherwise no one would buy them because they are more expensive."

Seems to me that the author just said that all the companies have been doing this and Holley finally got on the bandwagon. So why are you slamming Holley, and not the others who are reported to have led the way in a deception of the consumer? Seems if you bought another brand, according to this article, you'd have to do your own flow tests to determine how accurate it is.

I didn't see anything which said Holley made a bad carb, just not exactly as advertised. A situation which seems to be fairly common in the advertising world.

Even with this slam, there are plenty of users who are happy with what they bought, and others who are not.

So, what has been gained by posting this information? Spike

1965 Ford Mustang Fastback 2+2, Vintage Burgundy w/Black Std Interior, A Code 289 C4 Trac-Lok; Vintage 40 16" rims w/225/50ZR16 KDWS BF Goodrich gForce Radial T/As, Cobra drop; surround sound audio-video... See my ride at.... Feb 2004- http://207.36.208.198/albums/86810/003_May_21_3004.jpgFeb 2004- http://207.36.208.198/albums/86810/005_May_21_2004.jpgJul 2005- http://207.36.208.198/albums/86810/davescar_7_11_05_002.jpgJul 2005- http://207.36.208.198/albums/86810/Engine_rebuild_006.jpg
Reply to
Spike

I bought a Holley, not someone elses, why would I blame Barry Grant for Holley lieing. If you or anyone else uses a dyno program to build a motor and it specifies the CFM for the carb for a set performance level and you buy that cfm carb and it dosen't perform to the level you expect because holley fudged the cfm numbers, you wasted the carb money because if you want the performance you expected you have to buy a different carb. Where's the integrity with companys anymore.

Reply to
cd1048

For that type of application, you want to OVERengineer the carb and dial back the jets so that you have some wiggle room down the line if you make any mods that require more fuel.

I'm not making excuses for Holley, because they are clearly misleading the consumer here, but if you're building out a motor, that's just common sense to build in a little padding on something as crucial as the carb.

Cheers,

Reply to
Ritz

the program called for 900 cfm,, I bought a 950, it's REALLY a 830 cfm. How much padding would you use?

Reply to
cd1048

and lets say I required a 900 and bought a 950 but was really a 830?

my car

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Reply to
cd1048

Fuck me thats one fugly car. Why not put Osama's head on the side with a big bullseye on it?

Reply to
cprice

ya got to love the USA, we have the freedom to hate and fight to protect it

Reply to
cd1048

It's been ages since I hotrodded a carburated engine, but I used to go

20% higher. So given your numbers above, in the olden days I'd have gone for 1100cfm or two smaller double pumpers. Fuel injection systems have gotten so much better these days that I just don't find it worth the hassle to use a carb anymore.

Good luck!

Cheers,

Reply to
Ritz

a pair

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Reply to
cd1048

a pair

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Reply to
cd1048

I agree that Holley ought to use the same vacuum to rate all its carbs. 1.5" Hg has been the standard since forever, and they ought not to change it, at least not without making a prominent disclosure, regardless of what the competition does. It wouldn't be hard to make that disclosure. The people who are into building their engines and who care about cfm aren't idiots (e.g., unlike the Prius owners who are getting all hissy to find out they only get 40 mpg highway and that their electric motors and battery packs just become excess weight on a highway trip. (Wait till they find out the battery packs cost $6000, when they have to replace them in a few years.)

Regarding the reliance on a computer program to choose a carb, though, you've got to keep in mind that actual cfm depends on actual vacuum in YOUR engine, which may or may not be 1.5" Hg.

When hotrodding a car you've also got to keep in mind the slogan "speed costs money, how fast do you wanna go?" This applies not only to the upfront costs of the "perfect" combo, but also for the costs of broken parts and parts that were not optimal and parts that went on the shelf when you decided to go in another direction.

There's a really great article about carb boosters in the next most recent Popular Hot Rodding -- in fact they've got it up on their web site right now:

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In anutshell, the author David Vizard states that you should generallychoose a carb with excess cfm, because you can tune it to your cid,heads, cam, etc., with the booster. It's the booster that introducesthe fuel into the air, and it's the booster that determines both lowspeed driveability AND peak hp. In fact, everything that David Vizard has written for PHR lately is great stuff. The first one I saw was about maximizing compression ratio. There was another one, more recently, about zero loss muffler and tailpipe systems. See if you can find them on the PHR web site.

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Reply to
one80out

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