Alright, I'm building 3x2 setup. I currently have 3 97's that I just rebuilt, and an Offy 3x2 manifold for a SBC... During my adventures of rebuilding these carbs from rusted solid junk, I've had many outside opinions from here and there... The 97's look great, but I'm being told that they're a real pain to syncronize and adjust, and that they don't move much air and fuel, so I'd probably have to run a striaght linkage using all 3 carbs at once. From what I can tell, this seems to be a bit of a pain when adjusting your idle and mixture. So... I was thinking of saving the 97's, rebuilding some 94's, which still have a similar look to the 97's, but move more air, are equally difficult to syncronize, but I can run them progressively, and if I'm simply toodling around town I could even go as far as disconnecting the outer two carbs to conserve fuel. With that in another conversation, someone asked "why don't you just go to Rochesters? There's usually one or two of them in every junkyard. They're easy to rebuild, and they're not as touchy as 94's or 97's..." So I'm confused... I'm not building an era correct car, so using the best of nostalgia parts isn't that important. I don't mind some challange, because that's what makes it good and fun for me, but on the other hand I don't want to be stranded somewhere because my carbs aren't set right... I'm looking for advice from people who have been through this, or links and resouces of information pertaining to it. I've searched the HAMB for previous posts similar to this, but came up with nothing every time I searched, so I don't know what I was doing wrong. Any help would be appriceated. Thank you.
If you use 94's you will have a total of roughly 480-580 cfm available depending on which venturi sizes you use. Ive written up tuning details on here so they should be archived. I have 3 on a warm 292 Y Block and they were a snap to set up. Rochesters are typically 225-250 cfm each for the early models. You just cant pull 3 2GC's out of a boneyard and expect them to work. They come in different sizes and they are prone to vacuum leaks at the butterflys which is why GM went to special blades for their tripowers. They can be used on a pretty healthy SBC but you didnt mention size or internals??? I tried that setup years ago on a 327 with the 350hp cam and they ran strong but I could never get them to what I felt was perfect. Spent lots of time with jets and a UniSyn; finally went to an Edelbrock intake and AFB. Years later and a bit wiser I wonder just how good that Offy really is in the flow department? Their one for the Y Block sucks; Im using an Edelbrock 573 on my Y.
On a GM rochester 3-2 setup, the outside carbs should just be venturi's with accelerator pumps. Only the center carb should have the idle circuit. So that elimiantes any need to synchronize the carbs. The progressive linkage kicks open the outside carbs once you stomp on it. So they are fairly simple. The 97 are supposed to be proned to leaking. Charlie Price at Vintage speed in FLA will answer questions if you give him a ring.
Thanks for the input... I purchased some odds and ends rebuild parts from Charlie, but I've been a little nervous to ask him questions, every time I call they seem extreamly busy, and lately they're only answering the phones on Tuesdays and Thursdays due to workload. But I'll give him a call Tuesday. Thanks for the replys... Dave
Dave..if you end up with extra Rochester stuff let me know. I'm slowly pieceing an old Poncho tri-power together but have only bought the bare intake so far. Also, did my buddy, Joe Cool get ahold of you regarding selling your model A? He was telling me he was interested.
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