I hate Holley Carbs!!

[michaelmopar]

I have a 650 vac sec and it seems i get more throttle responce and or performance out of it verses the edelbrock. BBBUUUTTT i have to adjust the idle vacum every couple of days. i will be driving along and come to a stop on the open highway from 65 to 0 and it will almost die on me unless i put it in neutral or ride the break and gas at the same time. i will adjust the idel mixture and idle speed and i will run great for a few days then same crap again. i did not have this problem out of the carter at all but was lacking in performance. so i give up on them i bought a remaned thermoquad today for 125.00 it is a 800cfm i was told it will rock and i am looking forward to installing it. FYI. thanks i needed to vent my disapointment. LOL

[DartGT66]

I think it has something to do with your power valve, maybe you are close to the edge of having it open at idle and that causes problems with the mixture. All the carbs work decently when tuned right, and none do when tuned wrong. Hopefully your thermoquad will work great in your application, if it doesn't, put the holley back and tune it right. For some reason, if you go to a street race or what ever performance car happening without carb restrictions in the rules, they aren't actually crowded with Thermoquads, AFB's or Rochesters.

[dwc43]

Originally Posted by michaelmopar

I have a 650 vac sec and it seems i get more throttle responce and or performance out of it verses the edelbrock. BBBUUUTTT i have to adjust the idle vacum every couple of days. i will be driving along and come to a stop on the open highway from 65 to 0 and it will almost die on me unless i put it in neutral or ride the break and gas at the same time. i will adjust the idel mixture and idle speed and i will run great for a few days then same crap again. i did not have this problem out of the carter at all but was lacking in performance. so i give up on them i bought a remaned thermoquad today for 125.00 it is a 800cfm i was told it will rock and i am looking forward to installing it. FYI. thanks i needed to vent my disapointment. LOL

I agree with ya. For the amount of parts involved it's the worst carb ever made. They never stay adjusted. The only one that I know of that blows a power valve every time you get as back fire. Your TQ wont do that. We run the TQ on just about everything we build, unless a rule requires otherwise. I know our TQcars slow down when we have to run a holley on them and your old edle junk is no better.
Due to the spread bore feature your TQ will be much more throttle responsive than any holley. THey're easy to adjust as well. IF you step on it and you get a bog, all you need to do is tighten the tension on the secondary air door spring. Look for a screw slot and a locking ring on the drivers side to make that adjustment. IF you need any help with set up let me know.

[DartGT66]

I don't know what you are doing wrong with these carbs. Holleys were used as factory equipment in the late 60's and early 70's in several BB mopars. They didn't need daily tuning. I have been using Holleys since I got cars, and have also used most every other four barrels, and I have yet to blow out a power valve despite of hundreds of back fires. I have actually never even seen a blown out holley power valve, so it's not something you have to deal with daily basis. I have seen a lot fo people who think they had a broken power valve, but after looking their problem has been elsewhere. The blowing power valve is pretty much a myth according to my experience, and one of the excuses those not knowing things keep telling as a reason for not using one.

[dart662dp]

sounds like the holley is sucking air somewhere. possibly a wore out throttle shaft. check all gaskets for leaks. does the holley "whistle"?
the edelbrock is a good carb, usually much more responsive on a street driven vehicle, and yields better fuel economy. (when properly tuned)
most holley's built after the early 90's have built in power valve protection, which is a check valve in the bottom of the throttle plate.
can't comment on the thermoquad, i have a drawer full of them and never tried one.
throttle response/driveability-edelbrock
top end HP- holley
TQ-?

[Kevin Garceau]

if holley's sucked so bad why do so many companies copy them and sell under their own name? Why is holley the most used brand of carb in racing today? Why did all manufacturers use them on different cars through the years....

back fire? if your car is tuned right it wont back fire.

You have a vacuum leak, plain and simple. Fix it and tune your carb accordingly without the extra air going into your motor.

[1973Swinger]

I have to agree with Kevin and the others, If a thermoquad was the best carb ever invented, and Holleys were really bad carbs, you would see thermoquads on every other race car and all of the companies out there would be copying their design. sure, for a stock street car, they are fine, but the Holleys really shine on built engines and do extremely well when tuned by someone that knows them. If Holley made such a bad carb, why are they the most popular carb through the years? It sounds to me like you need to make sure that you have no vaccum leaks or bad gaskets in the carb, then take it to someone that knows Holleys, or do some research and learn them yourself. Thants just my .02 though. Its good to take advice from others that have more experiance than you, but you also have to take their advice with a grain of salt and learn what works best for you rather than limit yourself based on someone elses opinions.

[John Kunkel]

Originally Posted by dwc43

The only one that I know of that blows a power valve every time you get as back fire.

Maybe you should consider the possibility that backfires aren't normal and tune to prevent them.

Your TQ wont do that. We run the TQ on just about everything we build, unless a rule requires otherwise. I know our TQcars slow down when we have to run a holley on them and your old edle junk is no better.

A plastic carb that warps and cracks isn't much better, the fact is all brands of carbs have their problems and the Thermobog has its share.

Many of the problems I see with Holleys come from other sources and/or endless "tinkering" without understanding how the carb works. I run nothing but Holleys, run them out of the box and get consistant performance.

[pishta]

The Holley PV is a weak link for sure. Any spit from the intake will give the PV a nice bump. It has (had since the advent of the PV protection valve) nothing between the vacuum of the intake and the fuel supply except the diaphragm,and those get crusty and brittle just like all other Holley gaskets. Ever take apart an old holley and find out that all the gaskets are about 90% of their original size? These carbs have been around for ever and get recycler through every venue. Ebay is flooded with Holleys and most are altered, very used, worn throttle shafts, drilled out idle bleeds, mixed up components due to their modularity and second rate aftermarket rebuild parts. I would look into the throttle shafts for your poor vacuum at idle and do a general clean up with a carb dip and compressed air. A new Holley works great. Demons are an advanced Holley design with all the popular hop ups arleady incorporated. Carter/Edelbrocks are rock steady once you get them dialed in, TQ's need a little tuning but are a good carb also. I have blown out a PV. I also buckled a top plate of a cross ram, but that was my fault. Run what works for you.

[B1owner]

Originally Posted by DartGT66

I don't know what you are doing wrong with these carbs. Holleys were used as factory equipment in the late 60's and early 70's in several BB mopars. They didn't need daily tuning. I have been using Holleys since I got cars, and have also used most every other four barrels, and I have yet to blow out a power valve despite of hundreds of back fires. I have actually never even seen a blown out holley power valve, so it's not something you have to deal with daily basis. I have seen a lot fo people who think they had a broken power valve, but after looking their problem has been elsewhere. The blowing power valve is pretty much a myth according to my experience, and one of the excuses those not knowing things keep telling as a reason for not using one.

I couldnt agree more. I NEVER EVER had a power valve blow out. And Ive never seen one yet. But Ive seen where the internals warp and crack on my dads old thermoquads and flood the crankcases of his old 400's with gasoline.

[TK]

IMO?
Should have tuned your Edelbrock, good carb.
Since you chose to have the Holley, they do need more adjusting with weather conditions, so what, you knew that.
I haven't had one of my carb'd engines backfire in years, so that ain't no issue.
Sounded like your float bowl was too high, or like was said before, vacuum leak.
But hey, you have a reman thermoquad now, the best carburator ever built! I hear they never, ever, ever cause any problems, never leak, warp, the throttle shafts never wear, and they perform so much better than ANY other carb out there. You should have quit reading all those magazines and learned how to tune your Edelbrock instead of wasting all that money on all those needless carbs.

thanks i needed to vent my disapointment. LOL

[dodger1]

Jeez, dtkboy, I guess TQ jet wells don't crack in that Alaska cold, eh? Kidding aside, and I don't have much experience with Holleys, I think part of the problem lies with the fact that Holleys are so tuneable, whereas Carter's designs are not (in comparison) And we tend to fiddle our way out of tune more often than not, since thats what we do, right? So, I like my TQ cause, once I found out about the do's and dont's I built a good street carb out of one. But can I tune it like a Holley? Nope. Plus the spread-bore vs. square-bore adaptations, although Holley does make a spread-bore carb. Then there's linkage compatibility. I won't even try a guess at what mm's carb problem is, except to say that blaming the basic design is not really a solution. Time to hit the books, mike!

[Billydelrio]

michalemopar, the timing advance could be playing games with you also.

My brother's 4150 Holley was not too bad to tune, but I do like my Carter/Wallace AFB much better.

[dwc43]

Originally Posted by DartGT66

I don't know what you are doing wrong with these carbs. Holleys were used as factory equipment in the late 60's and early 70's in several BB mopars. They didn't need daily tuning. I have been using Holleys since I got cars, and have also used most every other four barrels, and I have yet to blow out a power valve despite of hundreds of back fires. I have actually never even seen a blown out holley power valve, so it's not something you have to deal with daily basis. I have seen a lot fo people who think they had a broken power valve, but after looking their problem has been elsewhere. The blowing power valve is pretty much a myth according to my experience, and one of the excuses those not knowing things keep telling as a reason for not using one.

I've replaced a bunch of power valves over the years. You must not work on too many of these carbs. Last one was on a Chevelle of all things and it was busted. I have the tool and vacuum pump to check them with and if you use a holley carb you better buy one.

[dwc43]

Originally Posted by Kevin Garceau

if holley's sucked so bad why do so many companies copy them and sell under their own name? Why is holley the most used brand of carb in racing today? Why did all manufacturers use them on different cars through the years....

.

For the same reasons sheep and lemmings flock to chebbies,ferds,Mopars, and edel intakes when it's not always the best for there combo. Just because every nut usesw one does not make them the best.

[dwc43]

Originally Posted by John Kunkel

Maybe you should consider the possibility that backfires aren't normal and tune to prevent them.



A plastic carb that warps and cracks isn't much better, the fact is all brands of carbs have their problems and the Thermobog has its share.

Many of the problems I see with Holleys come from other sources and/or endless "tinkering" without understanding how the carb works. I run nothing but Holleys, run them out of the box and get consistant performance.

Was not my car that back fires. I just finished helping a guy fix his car over the net. After checking enough and asking enough questions I find that the heads were milled so much that the intake needed milling and they did not do this. They stuck double gaskets under it. A great source for a vacuum leak. I'm waiting to see if he fixed it yet. I'm sure it will take a week ot two to find out. Never had any problems with warped TQ bowls. I've heard of them, but never found one. I did break one on a race car one time, but it was hit by debris during a crash.

[John Kunkel]

Originally Posted by dwc43

Was not my car that back fires. I just finished helping a guy fix his car over the net. After checking enough and asking enough questions I find that the heads were milled so much that the intake needed milling and they did not do this. They stuck double gaskets under it. A great source for a vacuum leak.

I'll repeat, backfires are not normal. Prevent backfires and you won't have blown PV's (or update to $10 blowout preventers). Do you blame the block when a busted connecting rod spits out the side?

Never had any problems with warped TQ bowls. I've heard of them, but never found one.

Pay the freight and I'll send you a box full.

[Kevin Garceau]

You guys forget DWC is NEVER wrong, his word is gospel and if you dont believe it you are all stupid.

Many people will run whats the best, and it doesnt matter what others are doing. Many people have more money so they could buy/build the best yet choose a Holley carburetor. Even the mopar greats would do what ever it took to win and didnt care what they ran, Landy, Sox, Mr. Norm....they didnt care what was cool, or trick at the time they wanted to go fast.

I too have never blown a power valve. I usually ran PV not removed them, they are in there for a reason.

Although last few years have run injection... I like it better than any carb I ever ran. Although if I run this year, may run carb just to get out.

[bigiron]

I've read a little about TQs but have not had the oppertunity to run any of them. I run Holleys for the most part, but I do have some Carters, and demons.

I have no problems tuning any of them (with the exception of the Race Demons, which in my opinion; are the biggest pieces of junk on my car... quality control went out the window there)...

The question I have is that if the TQ is such a good carb why are they no longer in manufacture?? What was the reason for there demise??? Was it that noone understood them (problems with configuration??).

As far as spreadbore design... what advantage does TQ have over a QJ or Holley spreadbore??? In the past I have talked to guys that said the Holley was hand over fist above the others... but they couldn't explain (to any kind of satisfaction) why.... I have also heard these carbs are notorious for bogging... all three do this from my info... granted it has to be an adjustment but there must be a reason they got that reputation... do they ALL need that kind of attention??? If you set them and forget them, why do they have such a bog prone reputation... or is it that all the techs of the day were so unaware as to how to make the carb work, that it was better to just quit manufacturing it??

Lastly.. if you put a Holley on your engine and it slowed down from what the TQ ran... doesn't that imply you mismatched your combo??? To clarify.. the TQ might be rated at 800cfm... that does not mean that an 800cfm Holley is going to match the performance... it is just the way Holley rates their carbs... We have all debated the difference between Holley and Demon... Where Demon out performs Holley (I now have dyno slips that proved that false... at least to me)... but the debate rages on...

I am not saying the TQ is good or bad... just fishing for information...

[Crank]

i been using holley's for 30 years now and still love them because of the ability to tune every bit of it and i can even up grade the parts as i go or replace any part on them.I keep hearing this bog problem it's not the carb its the guy tuning it.their is allot of good books out their on holley's if you can read you can tune it it's simple .i've also had just about every carb brand out on one thing or another but they limit me on tunabilty and parts so i stick with holley.

[Crank]

BTW i blew a power valve aaaa 22 years ago ?does that count?

[dodger1]

Bog? Thermoquad? It's the air door!! If it opens too fast, too soon, you get a bog. The secondary throttles opening rate isn't really adjustable. Only the timing of the air door opening (and to a lesser extent, the secondary jets and choke pull-off/air door dampener)) will control the infamous BOG. Apparently lots of us fell prey to removing the pull-off when the choke was removed, not realizing that it ALSO dampened the opening RATE of the air door. Result? BOG! As for the question of why it is no longer in production, the Edelbrock AVS is a pretty close cousin, with the same air door controlled secondary, but without the sometimes troublesome phenolic float bowl assembly. I still think it comes right back to tuning ourselves out of the picture and blaming a basically sound and well-proven design (Holley or Carter) for our own goofs and impatience.

[dwc43]

Originally Posted by bigiron

The question I have is that if the TQ is such a good carb why are they no longer in manufacture?? What was the reason for there demise??? Was it that noone understood them (problems with configuration??). ...

Carter was bought out. There were no real problems with the configuration.

As far as spreadbore design... what advantage does TQ have over a QJ or Holley spreadbore??? In the past I have talked to guys that said the Holley was hand over fist above the others... but they couldn't explain (to any kind of satisfaction) why.... ...

The TQ uses two sizes or discharge boosters which covers a larger rpm range and gives it more throttle response over the single booster holley and quadra junk. It also meters fuel better than the other too. It also has no need for a power valve like that holley does.


...

I have also heard these carbs are notorious for bogging... all three do this from my info... granted it has to be an adjustment but there must be a reason they got that reputation... do they ALL need that kind of attention??? If you set them and forget them, why do they have such a bog prone reputation... or is it that all the techs of the day were so unaware as to how to make the carb work, that it was better to just quit manufacturing it??...

The TQ will only bog if you adjust the air door spring to allow the door to open too soon. If you don't mess with it, it wont bog, ever. The holley needs squirters sized, accelerator pumps increased from 30 to 50 cc'c in most cases. Then there's cams to adjust there timming of the pump shot as well. Too many things to adjust when you can make just one adjustment on a TQ. Can't say a lot about the quadrajunk, I have driven a race car or two with them and they both sucked. They are very inconsitant as to when the secondaries will open. THey will bog at any time no matter what you do to them. They are less responsive than the holley.



Lastly.. if you put a Holley on your engine and it slowed down from what the TQ ran... doesn't that imply you mismatched your combo??? To clarify.. the TQ might be rated at 800cfm... that does not mean that an 800cfm Holley is going to match the performance... it is just the way Holley rates their carbs... ...[/QUOTE]

The holley was not mismatched, it just wont performa as well. IT's not as throttle responsive as the TQ. It does not accelerate as fast wit the holley due to the lack of throttle response. Plus it does not always flow 800 or 850 if the engine does not need it. The holley will always deliever the same at the same throttle opening where the TQ will give you what you need.

[DartGT66]

It must be, that the holley users are just plain stupid and ignorant.
It must be that the aftermarket is just plain stupid and ignorant, when they chose to build a Carter, they chose the AFB. When they chose to refine it, tehy installed the AVS's spring loaded air door to AFB. When they reinvented the spread bore, the design was rochester.

I guess it's just, that some people are not interested in performance. Will put my dominator in to dumpster tonight, and find my self a couple of thermoquads for replacement. Anyone willing to guess the performance gain? There is one thing that should make everyone understand how great carb a Thermoquad is; there is practically no tuning parts available for one! It must be, because it's such a great carb that it doesn't need any! One carb fits everything! Other carb manufacturers propably don't know anything about carbs, otherwise they would build one with a magical throttle response too. I wonder if all the old carter engineers exploded, or something, at the same time the manufacturing ended. One might think that the revolutionary secrets would have created some interest among the other carb manufacturers and racers. But as said before, they just have to be plain stupid and not interested in performance or winning. And think about it; you can get those carbs from swap meets almost free! It must be one of the best kept secrets ever.

[pishta]

Originally Posted by DartGT66

And think about it; you can get those carbs from swap meets almost free! It must be one of the best kept secrets ever.

It may well be. I sold a rebuilt one on ebay for 130.00 and the guy was begging me to end the auction early. I was also selling a 3310-3 that was already rebuilt and was in great shape and I couldnt get 75 bucks for it. If Demonsizzler would publish a book on his little secrets, I believe the cat would be out of the bag for Mopar builders as they are probably the ones who would appreciate them most, and maybe some International guys and the one year Fords. Offy sells a dual quad top for one of their staggered top manifolds and guess what carb they chose to display it, the TQ, as strange as that may seem. I wonder if someone made a billet Aluminum center section for the TQ if it would sell, just to get over the stigma of the old "warped" or "cracked" phenolic design.

[DartGT66]

I'm not hte one saying, that some carb is junk. I have run thermoquads in the past, and in those applications they worked just fine. The first time I thought, "now This is a CARB", is after I installed my carburetor shop stage III 3310 Holley. the second time was when replacing out of a box 1050 dominator with one out of a pro stocker. And the last one was my Chuck Nuytten prepped 8896 pro street dominator. Personally I prefer holleys, because I can make those work and perform and have the parts needed for them.

[dart662dp]

i would like to see edelbrock incorporate a secondary "pump" into some of their products. many secondary "bog" issues due to engine not pulling enough vacuum to draw fuel through the venturies as soon as the secondary blades are opened can be overcome with one simple thing-PUMP SHOT!
spread bore type carbs with small primaries and beer can secondaries are generally more prone to this problem. where is the pump located in relation to where the carb draws most of it's cfm on the spread bore type units? transition nightmare by design?
i understand the theory of weighted "air door", secondary diaphram spring, secondary air valve spring tension etc... but still, a vacuum secondary carb is just that, vacuum operated secondary. which is dependent upon vacuum to open the secondary door, or blades (depending upon model) as well as pull fuel.
i run both edelbrock and holley carbs on my vehicles, and switch them out from time to time, but i always end up with the DOUBLE PUMPER back on within a week.
the edelwebber works great, and is a ton of low end fun, but it aint no double pumper.
i have never been able to make a vacuum secondary holley work worth a crap on anything much hotter than a stock motor, compared to the DP style carb.
ever look at a motorcrap four barrel from the late 50's or early sixties, the most primitave carb known to man, has a secondary PUMP! and the things worked quite well.
would you(all) prefer a vacuum operated tranny, such as the turbo 350 or c-4-5-6, or one that operates of off positive line pressure, such as a torque flight?

[bigiron]

OK... I am a Holley man... I did not come to be one by happenstance... After running all kinds of other carbs (with the exception of spreadbore type) I have found that they are the most consistant once I have them tuned. Like stated earlier anyone that can read, can tune one.

Demons are basiclly a Holley with a facelift and I have several of them they seem to be a decent carb as far as design.. but I won't buy another one because of Quality Control. The last 2 I bought were total junk... but again, the design was good.... (a facelifted Holley)

AFBs are a good choice (i guess) for the street, but in my experience they are not that good for SUSTAINED WOT... If I fatten them up for WOT they are rich and slugginsh off Idle... if I lean them up for off Idle I have problems with detonation on the top (good street carb though, where your not shoveling huge amounts of air through them)

As far as TQs are concerned, I have always stayed away from spreadbore designs, I guess, because of the reputation... then because of; they were out of manufacture... which I still have a problem with... and like the AFBs they might be a good street carb; but even at the local tracks I see Holley designs on all the big guns.... when I see the money makers running TQs and AFBs I might take another look at them.. but I have generally been pretty happy with "running what the winners run"

[pishta]

Originally Posted by DartGT66

I'm not hte one saying, that some carb is junk. I have run thermoquads in the past, and in those applications they worked just fine. The first time I thought, "now This is a CARB", is after I installed my carburetor shop stage III 3310 Holley. the second time was when replacing out of a box 1050 dominator with one out of a pro stocker. And the last one was my Chuck Nuytten prepped 8896 pro street dominator. Personally I prefer holleys, because I can make those work and perform and have the parts needed for them.

Dart, making a jump from a stock (?) TQ to a C.S. Stage 3 750 Holley would probably brighten anyones day. Going from a box stock 1050 to a "refined" pro-stocker, and finally the Nuytten built Dominator, these are all highly tuned carbs in their own right. I wonder how a Demonsizzler prepped Super Quad would fare against some of your jewels? I guess the right tuner can make any carb work well. How about a "carb masters" build off. Same 440 or whatever and 4 carb tuners with their own models, Nuytten, Sizzler, BG, Holley HP, Predator, Biggs, ProForm, Edelbrock, Carb Shop, whoever. Looking at peak HP, Torque levels and driveability. I agree the Holley stands out as the one supplier that still backs their product with upteen different cams, PV's, shooters, blocks, plates, jets, bodies, bowls, linkages, adapters, boosters, floats, bases, venturis (oops, only BG does that), gaskets, pumps, diaphragms, (whew..did I miss anything?)

[TK]

I wish I could find one of these secret weapon thermoquads. Every one I have ever ran felt just like a Edelbrock, or worse.
Holley's work fine, as long as they arent those cheap vacuum secondary ones with the tube going from bowl to bowl.
I prefer AFB's/edelbrocks. I also rather have a quadrajet than a thermoquad. But no carb is really junk.