I have Chevy 348 with tri-power. No matter what I do, the performance is not what I expect. I don't want to invest anymore in what appear to be marginal carbs. I'm considering purchasing a full set of carbs or base plate and rebuild kits from Vintage Speed. They are much cheaper than Hot Rod Carbs (which appear to be really high quality). However, some older feedback (2006) suggests that that Vintage Speed was a problem for some people. I was wondering if the current situation with them has changed. Any feedback would be much appreciated. I don't mind speeding the money, but I would like to solve this carb problem once and for all. And selecting a good vendor is obviously key. Thanks, donsz
I don't expect a huge increase, the engine has a mild cam, so I'm hoping for 280 HP. Right now it runs rich and it won't lean it out any more. Also the engine, while great torque, seems to bog down on acceleration. I have rebuilt the carbs a number of times. Each time performance was better, not still not where I think it should be. I think at least the throttle plates (stock -small base) at minimum need replacing with quality units. I know when these carbs run correctly they are great (even though some argue that a 850 cfm four barrel is at least just as good performance-wise). It seems getting them right can be problematic if the start point isn't good (quality carbs). But they do look great. donsz
Maybe have them rebuilt? Talk to Carbking, He's on here or call him. He has good feedback. http://www.thecarburetorshop.com/ Sent from my SM-G900V using The H.A.M.B. mobile app
maybe just putting in rebuild kits is not the solution - there can be worn, slightly bent, etc parts not obvious to you - setting up the linkage correctly can be a real challenge - post pics of your motor with carb set-up - do you know exactly what year, model, car/truck, etc that you motor is from and has it been rebuilt?
To answer your original question, Vintage Speed has become a "Last Resort" source for me. If there is absolutely no one else that can solve your problem, you may have to go there. If there are any alternatives, I would use them first. "CarbKing" mentioned above would be a good place to start.
I can give you lots of feedback as I have spent the last few months getting my rebuilt carbs happy with bases for the outboard carbs on a fresh rebuild of my 409. Lot of factors at play to get the performance. Give me some more background on the motor itself re age ignition etc Sent from my iPhone using H.A.M.B.
The engine is a rebuilt 1965 truck 348, mild cam and slight bore. Ignition is electronic. I am running a fuel pressure regulator, about 2 psi. I realize these engines do not provide earth-shaking performance, but they do have some grunt when right. I bought the carbs and manifold as a set off eBay. They seemed like a good price (about $1100)and looked good (not original carbs). Ends up they did not work well at all. It seems like there are plenty of people selling when they represent as original or at least good running tri-powers, but they end up being sloppy pieces of work. I learned a lesson here. At this point, I wouldn't mind spending a little money and getting them right once and for all. Attached is a picture of the engine in my 1957 NAPCO. donsz
My advice is to contact dickster27 here on the HAMB, he runs Dicks Hot Rod Carbs. Work with him to get a tuned set of good carbs for that baby.
What size jets are in all three carbs? What outboard carb bases are currently installed? Are the throttle blades sealed tight and can you tune the center carb with effect right now? Sent from my iPhone using H.A.M.B.
Running Rich by smell or plug reading? If by plug reading by eye, the gas blend of to day off pump will always look Rich, get a Wide band AFR gauge , Vac gauge , Tac , timing light ,start there, then tuning needed , Cap off end carbs , start tuning with main Document changes. Experiment with timing about 15-20 Initial and total 32 to 40, Carb /carbs tuning takes time , more then just Jet changing,, I have spent over 40 hrs on 3 carb set up. those filter covers & paper air filter are restrictive , use K&N
2 psi isn't much. Have you tested higher? Gauges aren't always that accurate when the pressure is that low. You can crank up the pressure till it floods, then back off a bit. Are you sure everything else, like the ignition timing is right? Have you checked the advance curve and total timing vs initial? Have you verified that the timing marks on the damper are true?
????? The high horsepower version of that engine used a single Carter 625 CFM AFB. A factory setup with original carbs could SOMETIMES hold its own against the Carter 500 CFM WCFB, depending on other factors (rear end ratio, tire size, etc.). Incorrect carbs, with some of the repro bases, repro airhorns, etc., should be sold with a large bottle of Bayer. Jon.
Carbking no longer rebuilds carbs, but has a huge inventory of carbs to dispose of. And yes, manufacture kits. Jon.
The Jalopy Journal
