Well I gave up on the Tri-Power.....

I tried everything I could to get the 3 two's to run right on my 40. I even took the car to the "Guru". THis guy has a good reputation with multi carb setups and he was even stumped. Short of actually changing carbs I decided to replace the whole thing.

I had the 2x4 intake and carbs from my roadster sitting on a engine stand while the car is apart, and I knew it worked REAL good. So I spent acouple of nights and swaped it out.

The beauty of this swap is the 3x2 and the 2x4 intakes are identical as far as the placement of the thermostat housing and fittings for the temp sender and fan switch. Also the the throtle and kickdown cables end up in about the same spot..

Well tonights test drive ***ured me I did the right thing. THis car came to life big time.

Here's a few pics of the intake swap, befor during and after.

Notice the last pic the air cleaner got messed up from the salt at Bonniville. But it was sure worth it.

 

wrenching

 

almost done

 

ready for Billetproof

 

Intake swaps on a full fender car arent alot of fun but at least it was worth it. ****s about the Tri-power though.

 

That does **** about the tri-power!!!
Man that double 4 sure looks like its in the right spot !!
And I bet that test drive was gooood !!
Save me a spot on the cooler im going to come and see that car in person !!
Very nice work on the swap !
Im wanting to get some of that salt damage myself someday !!

 

Rudy,
I went through the same thing with the tri-Power on my 32. Sent the carbs to Larry at Automotion for a rebuild but it still didn't run the way I wanted it to. I probably put 10,000 or so on it but then changed to 2X4 like you are doing. Tri-Power looks cool but if yer gonna drive it, the 2X4 is the ticket. Good luck. See ya Sunday.

 

I may put the 3 two's on the Roadster when I put it back togeather and see if I can make it work. But for now I plan on doing too much driving with the 40. The problem was the stumble and lack of bottom end performance. I think the center carb was just plain worn out.

 

I would like to have a tri power set up but right now all I have is an edelbrock 2x4 setup. I'll trade ya!
What kind of problems are you having with the tripower stuff? I'm just curious incase I ever get one for my 54 instead of my two four setup. For right now I'll probably just run my two fours I have heard its easier to set them up than the three two's. What size motor are you running in your car? Mine has a dressed up 350 in it untill I can find a nice 283 or maybe a 327 to do some swapping on.

 

Remember, on those tri-powers that use the small Rochester 2G carb, the total flow is only around 600cfm. I ran one om my Studebaker with a 383 stroker motor, man was it lean going down the highway. The guy that has it now runs Hilborn EFI and picked up about a second and a half in the quarter with just more flow.

Doug

ps. sure did look good though!

 

Cool Rudy, I was affraid you where gona go to a single 4 barrel, 2x4's are just as cool as the 3x2's.

 

Rudy it took me about six weeks of trial and error with jets..air flow and acclerater pumps but I think I got the 3x2 setup on my sedan straightened out now. Not only does it look good but it runs great!!! They can be a real pain inna **** but worth it when you get 'em right. See you at Indy.

 

Like I said I think I will put it on the roadster when I put it back togeather. So Andy, I will want to talk to you as what you did jet size and and any other tricks you might know.

The point you made about changing accelorator pumps is interesting, because that is exactly what it feels like, a Bad eccelorator pump. It stumbles and boggs when you give it any gas. I know on a holley you can adjust when the pump squrits but the old Rochesters just have fixed rod.

What I'll do when I'm ready to use it again is start with a differant center carb and go from there.

And yeah Gus, the 2 fours look cool too

 

Nicely done.
I like the dual quads as well and they are easy to set up.
Looks like you're running progressive.
I like straight linkage on multi-carbs, but am tempted to make a progressive for my dual quads just for the fun of it.
Maybe . . . it runs so good now I hate to mess with it and like they say, "if it ain't broke...."

I had triple 2's running Rochesters with straight linkage.
All accell pumps operating on a 335" Rocket motor and it had good low end throttle response.
If you're running sans pumps on the end carbs I wonder if the poor low end response is when the end carbs throttle plates crack open dumping in more air, but not enough fuel to cover the momentary lean spot that comes in until the main jets are pulling fuel.

I don't think there's as much of a mileage gain as some think when using progressive linkage on triples.
A small amount in town due to being into the accell pumps more often, but when you're running the highways, even if all three have the throttles cracked open, the carbs are only flowing 1/3 as much fuel/air mix individually than a single carb would be when it's flowing enough air/fuel to maintain the same speed.

Looking at a single quad jetted correctly, if an engine is drawing say, 400 cfm during a climb up a grade, it's pulling X amount of fuel.
Stick on a straight linkage dual quad setup that's jetted correctly, run the same grade and now each carb is flowing 200 cfm with the gas flow at approx 1/2 X per carb.

Contrary to what some think, dual quads don't mean twice the fuel or twice the cfm at less than full throttle settings.
Full throttle settings will pull more fuel and cfm, but not too much more.
The carbs will only flow what the engine wants and the additional carb clears up what could be a flow restriction with a single carb.
Aside from looking good, that's all the additional carb does.
Granted, on some engines a major improvement in flow, in others . . . well, it looks good.

And then there's the six two setup with four of them blocked off....

 

How`s it going Dude?Your coupe came out great.
I`m having the opposite problem.The Tri-power on my
`34 390ci Caddy motor is awsome,starts up quick,idles beautiful,and is a joy to drive in traffic.A few times I
had a slight hesitation when stomping it.I atribute this
to not running acc.pumps on end carbs?(carbs came from C.P.)

I`ve got the stock 2x4s on my 331ci el dorado motor on the
RPU and it runs like ****!The carbs are original Carters
had rebuilt at a carb shop.They are in perfect shape.
Tried to adjust them a few times,but can`t get them right.
Changed linkage from both direct to progressive.They are so
blubbery and rough around town.Foul plugs after short time.

Love the looks of the quads and the old Helling air cleaners
but have been thinking about going to Edelbrok single 600.
If I don`t sell the car.

Good Luck...JR

 

Haven't seen you for a while BlownRanger.

Was wondering if you've tried lighter metering rod springs?

If you've got a cam in the engine, the lower vacuum levels due to the bigger cam will have the metering rods up out of the main jets and dumping fuel at idle and low speeds.

 

[ QUOTE ]
Contrary to what some think, dual quads don't mean twice the fuel or twice the cfm at less than full throttle settings.
Full throttle settings will pull more fuel and cfm, but not too much more.
The carbs will only flow what the engine wants and the additional carb clears up what could be a flow restriction with a single carb.

[/ QUOTE ]

Now if you could just get the flathead guys to realize this with their power-valve issues...

 

[ QUOTE ]
Now if you could just get the flathead guys to realize this with their power-valve issues...

[/ QUOTE ]

I think they will when they run up against AV8's single carb flathead in his F1.

Granted, the F1's no lightweight, but I think that particular setup will open a few eyes.
My favorite thing in the hot rod game is when someone shows up in a car/truck with modest looking engine and blows em in the weeds.
I don't think I'll be disappointed here.


I get some interesting comments about my very mildly cammed single 750 Carter Buick engine in the roadster.
Most of them seem to forget the light weight/light car/modest/sleeper style motor equation.
And some of them don't seem to be phased by the 462" sized engine. At least not when they're just looking at it.

What was it that Teddy Roosevelt said?
Be noisy and carry a big gun?

Ok, so it's paraphrased a little bit, but it's the thought that counts.

 

Rudy, I'll see you when you come to Indy. It's a little involved to go into on the board so I'll give you the info then. I've had my carbs apart so many times I could it in my sleep, blindfolded now!!!

 

Blownranger, You don't need accerlator pumps on the end carbs. Get the float level right and the right jets and it should be o.k. You should run 46 to 48 jets on the end carbs if it's a pretty stock engine. I run 55's on my end carbs but it's about a 400 h.p. small block chevy. Sometime you just have to play with the jetting a little to get 'em right. Make sure your ****erflies are tight on the end carbs so you are'nt pulling any vacuum through them when they are'nt open.

 

[ QUOTE ]
I think they will when they run up against AV8's single carb flathead in his F1.

[/ QUOTE ]

I rode in the opposite of that. A 3-2s 286CI full-dress flathead that only ran on the center carb. It hauled! Adding the extra carbs helps the top-end a little but they run just fine off of a single.

C9, Barney Navarro has been saying the same thing about multiple carbs for years. He says you should run his 3-2 setup on solid linkage so that all the chambers get an even charge of fuel. He told me there's nothing wrong with the Holley carbs either. Keep the power valves (just get the right ones for your vacuum signal) and have at it.

 

[ QUOTE ]
You should run 46 to 48 jets on the end carbs if it's a pretty stock engine.

[/ QUOTE ]

i am not positive what size i am running in the ponitac carbs i have but i would like to try experimenting with jets. where can you get them? i doubt my localk oreillys has them

 

Hudson Hawk, check your local speed shops or carb repair shops. They should have them. The size jet will be stamped on it. If you can't get them locally do a search on the web be typing in Rochester carburater. Hot rod carburation or vintage speed carry parts also. Buy some 1/8 in. thick, soft gasket material and make your own gaskets. It will save you money and time in the long run if you have them apart very often.

 

Ya know Andy, I had never heard of not running accelerator pumps in the outboard carbs. What about the power valves? The kit I used to change the bases said to block the power valves off.

Also what size jets are running in the center carb?
I think what I'm gonna do is gather as much info from people like you that got them to work and revamp the whole setup.

We need tripower tech week

 

Did I say acclerater pumps??? If I did sorry...I meant to say power valves. I run 50's in the middle carb. You have to drill out the fuel venturi to move a liitle more fuel which means you also have to drill out the air venturi to get the mixture right. You need more fuel for todays larger engines. These carbs were designed for the 283's and 327's back in the late 50's to mid 60's. You can get the later venturi which have bigger diameter fuel and air rods if you don't want to drill them yourself. Charlie Price offers a kit to set up the carbs for a 3 deuce set-up for about 300 bucks...but you take your chances on when he might ship them. I'll bring all the info I have to GG Indy and show you what I had to do to get mine running right.

 

So.....explain to my pea sized brain how the dual quad setup works.

Does the front or back carb act as the primary and how does it react with one carb sitting right on top of the intake runners versus being all the way in the back?

I have always liked the look of the low dual quad setup, I just figured it was always too much carburetion for my tame small blocks.

 

Root . . . they work great with straight linkage. Course, I'm prejudiced.

All of the progressive linkage dual quads I've seen use the rear carb for the primary. I'm guessing because the primaries in the rear carb are closer to the center of the engine. Seems too that a big plenum would help.

Far as chokes go - which are great for cold weather - I used a manual choke and operated both of them from one cable . . . but, you don't need to do that. I did cuz it seemed like the right thing to do.
A little investigation later on and talking to a knowledgeable Corvette guy who used to own a dual quad small block Vette, he tells me the Vettes use a choke on the rear carb only. He reports too that it worked quite well.
Makes sense to me. Even so operating both chokes off one cable worked great in my car.

Think too about the carburetor sizing.
Kenne-Bell who used to put out a whole lot of tech stuff about the late big Buicks recommends using two 750 Carters on their dual quad intakes if the engine is reasonably built.
I went for a pair of 500 cfms because I wanted a strong mid-range on the street. It turned out to be one of the best multi-carb setups I ever ran. Tip-in on the secondaries was smooth and the engine pulled hard.

Keep in mind as well the article Car Craft did a couple of years back where they tested intake/carb setups and deliberately used too big of a carb or carbs. They found they worked quite well. I agree with them and especially so with the Carters (or Edelbrocks). These carbs pull the amount of air the engine wants and if a pair of 750's is up top and all the engine wants is 1200 cfm then that's what the carbs will give. The opposite is true as well. If the engine wants more than 1000 cfm from a pair of 500's it'll draw what it wants. Not as efficiently as a pair of 750's, but it ain't far behind.

Your 'tame' small blocks would probably work fine with a pair of Carter 500's or a pair of Holley 450's.

Since we're thinking about interesting things here, howza about one four barrel and two 2 barrels?
The four barrel would be a Carter - where the air valve dictates when the secondaries tip in, which is to say when the engine wants more air - or a vac secondary small Holley and maybe a pair of Rochester 2 barrels on the ends that come in at about 60% of the throttle travel. With accel pumps on both.

Eye wash or killer setup?
Only the brave will know....

 

Back carb as primary. As stated before, the carbs will find the airflow they need - it's up to you to set the fuel flow, by changing rods and/or jets. I've run my progressive linkage since day one - two 500 Edelbrocks on a 406. Never touched them, out of the box, after checking plugs. You can see where I've got the linkage set to come in. No bog on the strip or street. I've never run a choke - starts right up with the MSD box. Sorry for the dirt - it's been sitting for a bit.

Mutt

 

I have a triple set up on my 33 pick-up on a tired 305 sbc.
Driving it normally, it's great! However, the motor's kind of a wheezer and when you stomp on it, basically falls on it's face.
I honestly don't think it has enough vacuum to pull fuel from the outboard carbs.
I'm running '66 GTO carbs, so their the larger bore.

I've done a few of the set ups before and had real good luck....mine's the only one that didn't work right.
I'm hoping when i get the 'new' motor done, it'll be tighter and be able to accept the set up better than the 305.

I also have dual quads on a 283 in my deuce. First i had the set up naturally aspirated, then huffed.
I'm using 2 500 Carters, with straight linkage.

Once i tuned them, they ran absolutely GREAT.
It starts right up (no choke), NEVER fouls plugs and is as drivable and any new car out there.
The only difference from natural to blown is i had to fatten it up a quite a bit.
I love the way the quads run.. Never though 1000 cfm on 283 cubes would work so damn good.



Oh yeah, Roadstar, i love the color of that motor!!
Man that looks good!

Rat....

 

I don't know jack about Edelbrock/Carter carbs......
I may hafta try this setup though. I have a 327 at the machine shop right now that needs to be picked up. This would be a sweet setup.