Has any one on here ran a tripower on a buick 401 before if so how did it do. I have heard that the nailhead needs alot of cfm to run good . im just building a cruiser not a speed bullet .
The Aluminum aftermarket tri power manifold leave a lot to be desired as far as flow & power. A single 4 will out perform most tri power set ups....................................
The 364 nailhead in my 55 has an offy 3x2 with Rochester 2gc’s and it runs great and really goes when the end carbs open up. But I admittedly don’t drive it very hard
Come on Mark,,,,quit showing pics of your cars in the shape they are in,,,,at least clean and shine them up a little first,,,,,,LoL. Man,,,,that is beautiful as always ! Tommy
My buddy Ben had a tri power on his 401 in his A. He was never really happy with it. Finally swapped it out with an Eelco 2x4 setup, and man does it run better. Nailhead’s like a lot of carb from my experience. One 4bbl is good. 2x4 is better. The stock 2x4 intake is great. The Offy one flows like crap.
If your gonna do a tripower, do it with Rochester 2GCs. I’d do it with a straight linkage. A progressive is gonna starve it of air and fuel only on the center carb. 97’s on a straight linkage are only gonna flow around 550 to 600 CFC max at WOT. Its not enough.
My avatar has a 425 nailhead with an eelco 2x4 with a pair of 500 cfm thunder series carbs and it run excellent, but 3x2s look nicer imo.
Thanks for all the info i think im going to stick with the 4 barrel for now and sell off the offy 3x2
I always liked the 3X2 setup I had on my 348. I drove the car for about 6 years with that setup, stock Rochesters with my own homemade progressive linkage. They are a bit finicky. If you don't open the end carbs for a while, the gas goes stale and the first time you get on it, it may not run that well. Once you get new fuel to the carbs it cleans up. The other problem is the end carbs not always returning correctly to idle. Even though the end carbs on the factory setup didn't have idle circuits, if the throttle plates didn't return to exactly the stop you had a big vacuum leak and poor idle quality. I learned to rev the engine and open then end carbs and then sidestep the throttle. That normally corrected the problem. I also have a 401 in my Model A. Haven't had it on the road yet, but I'm going with a single 4 bbl. I don't have room for multiple carbs.
Nailheads are easy to spot outwardly. The 264-425 engines had valve covers that, when looked at straight on, have tops as flat and straight across as the head of a nail. I believe the 300 was part of the next generation, standard Buick small blocks.
So my sedan came fitted with a 401, offy 3x2 manifold and 3 x 94's. I had read that the Offy flows really bad and robs power and that 94's wouldn't be enough carb, and I don't dispute any of it, but the car ran real good. If you check out my thread 'The shAm sedan' you will see I managed a 13.7 at the drags on bias plys. Not long after I fitted an Eelco 3x2 inlet and 3 Rochester 2G's and again the car felt really strong but at the drags only improved to a 13.6. Exactly the same car on exactly the same track. I have since got that down to a 13.3 with a switch to 650 rears. Conclusion is that both set ups seemed to work well, the Offy I believe can be made to flow better too with a little work. I have though moved on again to an Eelco dual quad and two 650 Edelbrock avs2's as I always wanted to run 2x4's. It will be interesting to see what it now runs at the track. Untitled by Gavin Meanley, on Flickr Untitled by Gavin Meanley, on Flickr
nice set up! It will most likely break the back tires loose when the second carb opens up at speed. That set up will run the best of all of them, once the tune is dialed in.
@ukgav was your tri-power set up with progressive linkage or straight? I have an Offy and had planned to run progressive and the 97 carbs have all been modded to suit. You mentioned yours ran well with the Offy and 94's. My engine is a stock 401, car will just be a cruiser so the tri-power is for looks only and my other 2 rods have tri-powers also. Nice Tudor and it's great to see something with an engine other than an SBC.
Already been on the dyno to get the fuelling right. Had to do surprisingly little to the carbs, just went down a few steps on the secondaries and slightly stronger springs on the metering rods. Both tri powers I ran were set up with progressive linkages. When racing I used to adjust them so there was less of a delay between middle and outer carbs opening but not much. Neither set up seemed to like being run straight up, there would be a hesitation when the throttle was floored then it would break the tyres loose. Probably could have been tuned out of it but already had my eye on the 2x4. I would launch with around 1/4 to 1/2 throttle then get into it.
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