Have Street Rod with: rebuilt Chevy 355 cubic inch small block Edelbrock high rise tri-power intake manifold Three Rochester carbs with progressive throttle linkage Isky solid lifter cam GM TH350 automatic transmission No manual choke. Can be stubborn to start when cold or sat for few days. Cranks well, generally starts easily when ran recently. Should one carb have choke? What is best technique for starting? Pump, don’t pump, depress, don’t depress accelerator? Thanks. Ernie Wickersham Avon, Indiana
Modern fuel evaporates and leave **** in the bowls. Many guys have went to an electric pump they can prime th carbs with just like a racecar. Make sure to add an intertia switch in case of accident
I only run my electric pump to prime carb until started, then switch it off and run only on mechanical pump. It greatly reduces cranking before the cold start. I suggest that yes, the center carb should have a choke to also help with starting.
Every engine is different...you need to find what works for you. If the bowl is drying out due to evaporation (pretty typical these days, as mentioned) then you need to get fuel to it first...so what you do with the pedal while it's filling, doesn't really matter. Once it has fuel in the carb, if there's no choke, a good plan is to pump it twice, hold the throttle slightly open, and crank it.
1wk cold start foot feed to the floor to squirt all 3 carbs . There should be enough fuel to allow this. Center should have choke that’s set to only to allow the fast idle sit on the first step especially if you idle in all 3 carbs. Electrical, exhaust heat, or manual for the choke is ok.
well my friend, unless you put some form of choke on it, be prepared for terrible starts no matter what you do. Sitting for a few days=absolutely refuses to start. Another option is to install an electric pump by the tank to push the fuel upstream-turn it on for a while then shut it off and let the mechanical take over. I don't do either to mine, just pour a little gas down the center, pump a few times and she starts then dies but does pull the gas up, so a little more cranking and pumping starts it. All fun in the hot rod world!
Due to evaporation issues a lot of guys will crank the engine over until the mechanical fuel pump fills the float bowls; this is hard on the starter, and if the battery is a little low it can drain it down to the point it can no longer crank the engine before the float bowls fill; then you have a dead battery to deal with as well, and eventually you're going to kill the starter too. I've learned a techniqu from @Boneyard51 here on the HAMB forum that works for me in this situation, and won't kill the battery (or the starter). When the engine has sat for a week or so and the fuel is all evaporated from the carbs, crank the engine with the starter only a couple of seconds at a time, 2 or 3 max. Then wait for about 5seconds and do it again. The fuel pump, because of the action of the diaphragm, will continue to push fuel up the line to the carbs for a few seconds after you stop cranking the engine. After maybe 5 or 6 times there should be enough fuel in the float bowls to get the engine to fire. I usually pump the throttle one time before cranking the engine, if the carbs have fuel in them the accelrator pump will shoot some into the carburetor throat, that will get the engine to fire. Don't pump more than that or you risk flooding the engine. Just crank it for 2 - 3 seconds, stop and wait for 5 seconds or so, give the throttle one pump and crank again. After about the 5th or 6th time the engine will attempt to start; pump the throttle one more time and hit the starter and it will usually fire up. A choke would help, but here in So Cal I've found I don't need one. Thanks to @Boneyard51 for this tip, it really works.
I run triple Holleys on one of my Galaxies and a choke is a must for easy starting cold. After a week or so I do have to crank it a wee bit to replace the fuel that has evaporated. Otherwise, a cold start is a breeze. Set the choke, crank it and it's running. Electric choke and fast idle working as on any other engine.
Pump the **** out of it until it fires. Continue to do so and feather the throttle to keep it running, restarting feguentky until you get on the road. Once rolling, floor it. Deal with this until you get tired of it, put your single four barrel back on. Admire your set up on the shelf until you can procure a proper center carb with a choke +58 Chevy works),convert choke to electric, reinstall set up with phenolic spacers under the carbs this time. Good luck. I have not made it to re installing yet. I drove mine, no choke over several winters, and in the Snow
My method with no choke is pump it a few times and then crank the starter with throttle partially open. If it's sat for weeks or months I often have to repeat once and it fires off. Since there's no fast idle circuit I just hold the throttle up manually for a few minutes until it idles on it's own.
MY method for cranking the "M-word" with a SBF engine and 600cfm Eddy carb is....... save the starter......save all the grinding....flooding....whatever... is to give it a good squirt of starting fluid (Brakleen/ether/carb cleaner) and it fires off almost immediately! Keep it running by feathering the gas until it idles on its on. Replace the air cleaner and off-I-go! Like you...once it cranks its usually good-to-go. Pretty simple 6sally6
With no choke you normally have to pump it. If your carb bowls have fuel in them pumping it will dump fuel down the intake. Do not over do it. if you are not racing it a choke on the center carb is proper. Most of the time we are hacks and proper is not important to us. LOL I try to tune mine to the point that you stroke it once when it is cold, this sets the high speed throttle. Hit the key and leave it alone for a minute until it is ready to be driven. I am not tuning yours so you will need to come up with your own process.
I like not having a choke on my 3x2 . I like to spin the motor until I have oil pressure ,then I start pumping the gas. Bill
All my carburetored vehicles have working automatic chokes. Unless they set for more than a week, they all start right up and drive off without dying. I turned wrenches in dealerships back in the mid to late 70's when car makers were dealing with emissions by running really lean. A properly set up choke allowed the owner to start and drive off without multiple restarts. I learned a lot about fine tuning a choke system during that time. Back in the 60's I had a 58 Impala with a 348 and tri-power. I converted it to a homemade progressive linkage which worked well. The center carb had the factory choke setup. It always started right up and drove fine. You just had to let it warm a bit before opening the end carbs.
There is no "one way does well on all and makes everyone happy" answer on the choke question. Personally, my feeling is that if it has a carburetor, then it has a manual choke. Both will start fairly easily at minus 10 degrees F. My dual quad shop truck has manual chokes on BOTH genuine Carter AFBs. And a tip from a Carter Carburetor Company engineer, that I have used with great success: "Leaving the choke in place even for a lot of racing conditions IMPROVES low RPM performance, as it acts as a straightening vane to help minimize eddy currents in inlet air". It definitely will improve street driveability, and slightly improve fuel economy (I know, we are hotrodders, who cares about fuel economy ). When I was still building 2GC 2-barrels for the local dirt-track circle racers, my carburetors would consistantly allow slightly quicker lap times for two reasons. One, I used the choke plate (but modified to stay wide open), and two, I calibrated the vacuum system to work the power valve the way the engineers designed it to work. Jon
I have practically the same setup. No choke on center carb. If mine sits for three days the fuel evaporates. I crank it for about ten seconds, pump the accelerator twice, usually starts right up but will quit unless you catch it and keep it running. Warm it up for about 30 seconds, good to go. Make sure the timing is right as well. They can be miserable to start if the timing is late! Like squirrel said though, all cars are different and require different setup. Also my car is low compression so I run 87 octane. Starts a lot easier on that than premium.
My 3 x 2 on a 348 Chevy has an automatic choke, but basically behaves like yours if it sits a few days. The fuel evaporates and even with my electric fuel pump it takes a bit to fill again. The choke helps a lot once it’s running. Thus far I’ve only run non-ethanol fuel (2500+ miles), but that too evaporates over time. So yes, choke helps. I live in Northern Oregon. John
Most of these guys know more about tri-power than i do, but does your center carb have place for choke? If so and you want to use electric choke you can get add for ..... shux i forgot how much i paid for mine. I've had it for about a year, still ain't put it on. LOL
-Electric fuel pump -Let fill carbs -Pump a couple times -turn over and as soon as it pops give it some throttle -get it running and use choke on center carb to set high idle warm up Some cars need full choke to start and some dont. Generally for me if anything needs a full choke at start up i push it in as soon as it fires, then clear it out a bit and then re set to warm up with higher idle. Electric fuel pump is a must have for me as some cars sit and i hate using the starters very long. Having an engine start quickly ensures proper lubrication inside.
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