Tri Power
- Thread starter rooster57
- Start date
Hotrod46
Member
Rooster, I'm sure Don will way in in this, but I believe he had a stumble with his 2x2 setup. He said he opened up the accelerator pump squirters and maximized the pump shot and it helped.
There's a lot of plenum volume with that adapter (even more than Don's) combined with the manifold that it's bolted to. Without a healthy pump shot, I would expect an off-idle and/or tip-in stumble. There is very little adjustment on the Rochester accel. pump.
The dedicated 3x2 manifolds actually have fairly small runners. Neither of my setups have throttle response problems with the dedicated manifolds. They have pretty crisp response, actually.
I know it's more expense, but I think you would be happier with the outcome if you go with the kit for the end carbs. My 2 cents and I won't mention it again.:win:
Mike
There's a lot of plenum volume with that adapter (even more than Don's) combined with the manifold that it's bolted to. Without a healthy pump shot, I would expect an off-idle and/or tip-in stumble. There is very little adjustment on the Rochester accel. pump.
The dedicated 3x2 manifolds actually have fairly small runners. Neither of my setups have throttle response problems with the dedicated manifolds. They have pretty crisp response, actually.
I know it's more expense, but I think you would be happier with the outcome if you go with the kit for the end carbs. My 2 cents and I won't mention it again.:win:
Mike
Hotrod46
Member
Well, I just checked Speedway.
$400 for the base and linkage kit.
$300 for the manifold. You might shop around and save some on this. Speedway is usually pretty hard to beat, though. Edit - Summit has it for $272.
You would still need rebuild kits or at least a new needle/seat and accel pump (x3). I think these are available from NAPA individually. The Speedway kit comes with gaskets.
Studs for the carbs. Air cleaners - basic 4" from Speedway $10 x 3, although you might want to go with something a little bigger. 4" is pretty restrictive (I'm running 4", so take it from me). K&N sells a GTO filter setup (6" round x 3) for about $150.
That leaves the fuel lines and a regulator. You can be as simple as a fuel block and hose or bend up some hard lines. Don't leave out the regulator (4 1/2 to 5 pounds).
You also have to run a small base distributor. Large HEI won't fit.
If you get your core carbs fairly cheap, you could easily do it for a grand or so.
Wish we were closer, I would help you. As it is, I'll do the best I can here.
Mike
$400 for the base and linkage kit.
$300 for the manifold. You might shop around and save some on this. Speedway is usually pretty hard to beat, though. Edit - Summit has it for $272.
You would still need rebuild kits or at least a new needle/seat and accel pump (x3). I think these are available from NAPA individually. The Speedway kit comes with gaskets.
Studs for the carbs. Air cleaners - basic 4" from Speedway $10 x 3, although you might want to go with something a little bigger. 4" is pretty restrictive (I'm running 4", so take it from me). K&N sells a GTO filter setup (6" round x 3) for about $150.
That leaves the fuel lines and a regulator. You can be as simple as a fuel block and hose or bend up some hard lines. Don't leave out the regulator (4 1/2 to 5 pounds).
You also have to run a small base distributor. Large HEI won't fit.
If you get your core carbs fairly cheap, you could easily do it for a grand or so.
Wish we were closer, I would help you. As it is, I'll do the best I can here.
Mike
donsrods
Member
rooster57 said:
Well, the setup I have is a poor mans way to get multiple carbs. It is an adapter that goes on a standard four barrel intake and mounts two Rochester 2gc carbs. I bought it from Vinatage Speed. For the first year of my T's life I ran a single Edelbrock 600 cfm carb and it was flawless in all respects. Ran smooth, lots of power, and one time on the interstate I even got 30 mpg, believe it or not. For those reasons I resisted changing it out, but I did want something that looked more old timey and more hot roddy.
I can't honestly say the 2 x 2 setup is nearly as good in the smoothness, power, or economy areas. In fairness though, I just bolted it on and never played with it. I think I have too much fuel pressure coming out of my Holley electric pump. I understand that these Rochesters like about 3 to 3.5 lbs of fuel pressure, so that could be part of my problem. It isn't so bad that I've had any real problems, but since you asked me to rate it I have to say a single four barrel still is the most reliable, troublefree setup.
But on the cool scale, there is nothing like 2 or 3 or more carbs sitting on top of a motor, so on that score I do like the 2 x 2 setup better. It changed the complexion of my car in my mind.
Don
I bought this setup for my Son Don. He's starting to collect parts to build an American Grafitti coupe clone.
Hotrod46
Member
Sorry I haven't answered sooner. I had to change the distributor in my son's truck last night. The pick-up coil in the HEI went bad.
The manifold I priced was the old style. I checked with Offy and Edelbrock, but they don't have one for your heads (you already knew that though).
Looks like redrilling the center holes is your only option for a new manifold.
Mike
The manifold I priced was the old style. I checked with Offy and Edelbrock, but they don't have one for your heads (you already knew that though).
Looks like redrilling the center holes is your only option for a new manifold.
Mike
dustytrails
Member
Screaming Metal
Active Member
putz said:
Hey Rooster.....just let me add something here.........OK.....more less this 'adaptor' has a carb base pattern like a big holley, right? OK, your engine is a 305.....it'll only take about 650 cfm max before it gets overwhelmed.......you can more or less run 3-200 cfm carbs,,,,,,,BUT......your gonna have 3 accelerator pumps shooting fuel into this pot more or less and then your gonna have a big bottleneck down to a single 4 area.....there's a lot of chance for fuel to fall out of suspension there..........some turbulence is good for mixing....alot is a bad thing unless you talking blowers and high pressures and big, tall tunnelrams......but thats another really involved tech article there.
I think Putz is concerned about all that fuel and air getting squeezed down into the mouth and spreading back open agian........that is my concern too.
Between all of us here on the board and the HAMB site.....we can probably find you a good used 3-2 intake to fit the smallblock probably for the amount of money you'd pay for that adaptor and therefore do it right! Yes.....2 carbs you'd create a overrich condition...................................and he's running 2 on his Bucket........................just as our fellow T'er said..........just think of adding another carb into his equation.
See what I mean?????????????????
If you can't find a intake to your liking.....find a Edelbrock C4B , take it to a machine shop.......with some scrap aluminum pieces.......they can mill out the top of the intake and put you a top on it for the 3-2's and it'll be custom..................just my 2 Pecos....................What ya think Ted??
:think:
one finger john
Active Member
Don, you have probably answered this before, but, does one of the carbs have it's idle circut blocked off? If so, which is the primary carb with the functioning idle circut? Also, do you have a progressive linkage set up on the carbs or are they hooked up one to one? It really is an interesting set up as far as tuning possibilities.
As always, love your T, hope to see your sons car soon.
John
As always, love your T, hope to see your sons car soon.
John
donsrods
Member
one finger john said:
Thanks John. Sometimes I wonder if Dan's car will EVER be done.:sad: (he hasn't figured out the concept of GET IT ON THE ROAD AND FINISH IT LATER yet) As for the carbs, I bought them done and ready to bolt on. Vintage Speed either rebuilt them or had them rebuilt with one of them using what is probably a Speedway base that has no idle screws in it. So I guess that one has been modified to just be a dumper.
I wasn't particularly looking for this type but they had the complete setup as you see it at their booth at Turkey Run and they made me an offer I couldn't refuse. I was actually holding out until Edelbrock released their tripower manifold for the Vortec engine (which is now available) but in some respects I kinda sorta like this one better as it sits up real high on top of the aluminum intake with the added height of the adapter. It makes for a nice view driving down the road.
After I get done putting my 27 together (trying to make the Billetproof Drags in Oct) I have to take some time to do some things to my 23, and the first on the list is to tame down the fuel pressure and play with the adjustments a little to try to cure the over rich thing.
Don
Similar threads
