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replacing old solex with holly?

4K views 24 replies 10 participants last post by  kwilford 
#1 ·
hey guys i wanna get rid of that old solex carb. i have a stock 70GT. i found a holly 2 barrell off of a chevy 151 HO 4 cylinder out of a vega GT. this has the square barrells like the weber and has circular*cant think of the word but the flaps at the bottom that actually allow fuel/air into the intake* all the linkages clear the manifold and it bolts up fine. has anybody ever done this before? is there goin to be any problems, mods, or anything of the such? please help i am in great need of some power! solex=slo-lex.haha:)
 
#3 ·
I asked this identical question in another forum about 2 years ago as I also a Holley carb. I was told then that it wasn't much better than the Solex and didn't have the same ability to fine-tune the jets, etc. as the Weber does. In the end I switched to the Weber and have been extremely pleased so far. It makes sense when you consider the aftermarket support the Weber has compared to what may or may not be available to an aging Holley.
 
#4 ·
all in all is it worth changing to a holly if i dont have the money to get a weber until school is out and i am working?
 
#5 ·
If your Solex works OK wait 'till you have the cash for a Weber. If not, pick up a used 32/36 off eBay and a rebuild kit to get you by. When you do have the cash, pay a little more and get the 38 DGAS, you'll be glad you did.

I ran stock '70 motor with 38 dgas, hot street/torquer intake, '75 manifold and 2" exhaust based on RallyBobs input and it really woke the engine up...

-Travis
 
#6 ·
the friend fo my dads that took me to look at the car in october*was origionally supposed to be for my dad at christmas but he gave it back* the guy said he had a weber and a set of doors i never got. i completely fogot about them until my dads friend asked about the weber when i told him i was considering putting a holly on it. then it rung a bell the PO still has a set of doors and a weber. got a hold of him today and asked wheres the rest of my stuff? he said he'd get it over to me but who knows how long thats gonna be. he said its been sitting in a bucket of diesel fuel to keep it from drying out. also on that holly would it be any different since it has came off a factory High Output motor? maybe better than the average stock 2 barrell holly? i can't afford no 38 dgas for i'm only 15 and the reason and purpose of my Opel is to be a daily driver for a few years until i get my 51 packard done. then the opel will be redone. until then its a daily driver/underpowered hotrod.
 
#7 ·
the holley question has been discussed a lot around the forums....the weber is not 'better' as a general sense. Holley are simple cheap and make a lot of power. A lot of rallybobs insane engines used holleys. But they require work to be done 'right'. The dgas weber is okay....not fantastic but I like it more than the solex. The solex isint horrible, it just is very finicy and needs a good amount of tlc to keep in top condition (IE running). Now if you have a bit more cash...more like $500 vs 200 or 300 you can look into dual sidedrafts. This is definitly the 'sexy' choice. I mean pop open the hood with two of these monster things sticking out the side of your engine and people are going to take notice. I like the dual sidedraft option...but dont get more wrong the holley can just as well as the dual side draft webers as far as cfm rating. I like the characterisitics of the side draft over the holley, the carb just feels stronger and more like a 'sports car' than a big block dragster I know with proper tuning you can get the holley to be a 'sports car' carb, but I still still have the weber as my first choice (money allowing). The one true advantage of the webers is the sheer number of tunning options, its much more flexible and easier to tweak then the holley. Once the inital tune is placed on the carbs they are SUPER strong. A friend of mine has an old triump with a big bore and dual side drafts and you can really hear the carbs...thats right hear the carb open up and start sucking more and more air in, what a rush :D The webers also have a ton of manifold options where as the holley is somewhat more limited. Both carbs with proper treamtent will make a huge difference in the big bore engine. On a 1.9 all of the option are too big for the engine IMO. Have fun and good luck.
 
#8 ·
THANK YOU KMON! information i was really looking for. so basically your saying weber and holly is basically preference for a stock GT? i dont know if i told you guys that the PO called and has a weber and doors. so i now have the option of a holly weber or solex but the solex is ruled out already.haha like kmon said its too damn finicy for a 15 year old to mess with all the time.
 
#9 ·
forgot whats IMO?
 
#11 ·
how comparable is it to the weber for power and milage?
 
#12 ·
There is one key piece of information that is missing from this conversation. A Holley is not a Holley is not a Holley. You're talking about different carbs here.

The Holley RallyBob has used is the 500 cfm 4412. This carb is generally used in applications where the 38 dgas can't keep up(160+ hp). The idle circuit of the carb requires extensive rework. This is not just swapping in parts. While the carb itself is quite cheap you will need to pay someone to do the modifications and you'll also need to adapt the linkage. This is way TOO MUCH carb for a stock or even mild performance motor.

The Holley from the Pinto is a different beast altogether. This is a design that Holley licensed from Weber based on the 32/36 DFAV. This carb is known to be of much lesser quality than the DFAV on which is was based and has the same fuel distibution problems. Basicly, since the primary and secondary are swapped, two of the cylinders run lean. This is NOT good for the motor.

-Travis
 
#15 ·
The Holley from the Pinto is a different beast altogether. This is a design that Holley licensed from Weber based on the 32/36 DFAV. This carb is known to be of much lesser quality than the DFAV on which is was based and has the same fuel distibution problems. Basicly, since the primary and secondary are swapped, two of the cylinders run lean. This is NOT good for the motor.

-Travis

questions for travis basically or anybody who knows for that matter. i do or do not have the same carb as the pinto carb previousely mentioned? also you say that the secondaries and primaries are switched. i assume you mean that the primary is on the inboard side and the secondary is on the outboard side, just opposite of what the stock carb is? so the 2 and 3 cylinder are closer to the primary and is goin to rob fuel from cylinder 1 and 4. is this why i can't use my holly off the chevy 151? the numbers i found on the carb are A 14 i do not know if that means anything but i guess its a way to make sure we're all talking about the same thing here. the PO is supposed to be bringing a weber and doors out that he just remembered he had. thanks to a friend of mine. its in a bucket of diesel fuel he said he did this to keep the carb from drying up and rotting the rubber parts. hes very slow so i'm not expecting it anytime soon. in short if the holly will not work for a month or two then i should just wait for the weber and see how that is right? this old solex is one piece of ****.
 
#19 ·
yes the primaries and secondaries are reversed. something i would never had given a second thought to if it werent you the wonderfull people among this site. just saved me from doing another engine swap that i just did over spring break. i''d like to thank all who had input it is greatly appreciated!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!:)
 
#20 ·
I like Solex

I have pretty good luck with the Solex carbs. They are a bit fussy but they an be made to run pretty well with some TLC. Using it wouldn't be the worst option in the world.

How is the throttle for the Vega carb actuated? I thought most of them were cable actuated, and if so you might be able to mount it backwards, with the linkage on the front, and use a cable to hook it up. Might be another option to look into?
 
#21 ·
I have had Solexs on two of the cars that I have driven and they always worked OK, they didn't run as good as the weber but they were acceptable. They were never rebuilt and both cars had been sitting for about 10 years, but they still ran ok.
I have the 38/38 DGAS right now and it works awesome! It came with my car and If I were to restore another GT(which is inevitable) I would probly opt for the 32/36, or maybe try Fuel Injection.
 
#24 ·
leans the cylanders out and *can* damage pistons, cylander walls, and burn valves.
 
#25 ·
Reversed Carb Throats

Well, maybe. RallyBob had warned that the "Pinto" style carb and Holley, with the reversed throats, can cause the outboard (I believe) two cylinders to run lean, due to the primary throat being inboard. I guess the theory is the flow path is shorter to the inner cylinders, so the outer cylinders tend to run lean. Now, when I look at a stock down-draft manifold and compare the flow path of a carb with an outer primary (such as the stock Solex and Weber 32/36 DGV), I really don't see much difference with the path that an inner primary would have. But at full throttle (with the secondary open), the condition is reversed. That is, the outboard secondary path of a Holley or DF Weber is better balanced than the DGV Weber. My bet is that the DGS Weber that Chris has is the best for balance, since BOTH throats open simultaneously.

And I had a Weber 32 DFM (a performance version of the dreaded "Pinto" carb) on my GT for about 50,000 miles, during which time it was run hard and put to bed wet. When I rebuilt the engine (at a total of 103,000 miles) it was in very good condition, with no difference in valve wear or other lean-related conditions. Now, as they say about gas mileage, your experience may vary.

The biggest problem with the reversed throats is the linkage has to be reversed. It took some monkeying, but by simply rotating the bell crank and replacing the pin on the throttle linkage with an offset pin, it worked pretty darn good. As for a Holley or Rochester, you will probably need to convert it to a cable, which is a bit of work, but eliminates all the inherent problems with the stock mechanical linkage.

HTH
 
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