QuestionQUESTION: race a basically stock ford 2.3l engine, stock cam, head etc with 135hp. changing from rochestor to holley 350 carb.what would be my first step in tuning the carb before trying it? want to minimize any pullover problems.
ANSWER: Start with a fresh rebuild. I usually strongly recommend a person who's starting out with the use of a Holley is to buy a new one set up for your application, many many times you save money in the long run and don't have the annoying "hit and miss" headaches with carb tuning to worry about along with all the other trial and error learning a person's dealing with in racing ( I assume you're racing this, right? If not there are a whole set of different parameters that need to be addressed for road use).
Circle track racers and drag racers need bowl baffles to eliminate sloshing. I highly recommend A back fire plug which installs in the base which keeps the power valve from blowing out in the event of backfiring.
Jet and select a power valve based on recommendations from Holley based on average climate, type of use, power band, rpm, etc etc (see where a person would be so much better off buying a pre tweaked one?) BE VERY realistic on these factors when deciding. Wishing you're shifting point will be 5 grand, and it actually happening on a day to day basis are two very different things.
On a used carb you need to be sure all mating surfaces are straight and true or air leaks will make your set up unstable.
Really, consider buying a new Holley set up to your specs. A Holley can be your single greatest asset or worst nightmare.
If you insist on putting together a used one, buy a Holley brand rebuild kit, use gaskets made for multiple use, you may be opening it up often, select a power valve right in the middle of the road (5).
Read up on, learn how to "read" spark plugs (inspecting them with a magnifying glass to determine how your combustion efficiency is).
If you can supply me with a lot more specifics I can help you zero in on your needs. OK?
---------- FOLLOW-UP ----------
QUESTION: OK, what info do you need?
Answer1. What is my car being set up for? Drag or circle track racing, mild, moderate or extreme street use.
2. Do you run a stock cam, if not, cam specs. You can think ahead and plan if you intend to put in a hotter cam.
3. What will your power band be? A good guestamate will suffice.
Drag racers and street cars plan from dead idle to whatever max rpm you plan to run, if for street use include what rpm you cruise at (highway vs an urban assault vehicle).
4. Any climatic extremes? High altitude, cold climate year around, areas like Washington state or the other extreme living in a desert, meaning a humid or dry climate.
5. Type of fuel you'll be running, racing fuel, or do you intend to run pump gas.
6. A run down on your rig, stick or auto, in stock street trim or stripped down. Do you run accessories (street cars) like a/c or heavy voltage running a heavy alternator. (big sound systems)
7. Stock oem intake? (just a note, find a fuel injected intake off like a later model turbo or ranger, plug the injector holes and make an adapter plate for the carb, these intakes are dual plane and make a huge diff in performance, are cheap and easy to find).
8. Stock exhaust? (once again, the later model trucks and SUV's that used the 2.3 had a header style exhaust manifold, relatively easy to find, help performance a lot, and are built road tough and won't rust out like a lot of aftermarkets).
I know some of these questions would sound silly to a person building a road car or a circle track racer, but a detailed picture of how this engine is going to be used makes all the difference in jet selection, power valves, (if your carb has an progressive barrel set up, like 4 barrels where a vacuum diaphram opens the secondaries, and some Holley 2 barrels the second barrel is operated the same way).
