Car Craft recently helped a friend pull a 1955 Chevy out of a yard where it had been sitting for more than two decades. The tires had sort of flat-spotted by growing into the ground, and the keys were long gone. The ’55 had been such a deal because it had an oddball 305/TH400 combo that had been swapped in after the original motor had nuked years ago. But the current owner warned us that the 305 had smoked like hell while driving from Idaho to California decades ago, explaining how it ended up getting parked for so long.
While the 305 was planned to just be a stopgap until the ’55 got a 377-cid aluminum-block Donovan engine, we still wanted to get the thing running. With years of an unknown history, we decided to run through a checklist before firing it up for the first time. Other than a set of $450 Weld wheels from Craigslist so it could roll around, the ’55 was just as it was pulled out of hibernation. Here’s what it took to get an unknown motor and transmission combination running and driving again.
Before starting, we made sure we had the basics on hand: a towel to sop up fluids and, of course, a fire extinguisher. Starting up a vehicle that’s been sitting for a while could mean fuel leaks, so it’s better to be safe than sorry.
We started with the most basic of questions: does the engine have oil? Even if it does, there can still be issues. Water contamination is a common problem, so if the oil is runny or milkshake-colored, it’s best not to even start the car. Ours looked OK, at least for a few seconds of running.
The trans fluid was next, and at this point, we just wanted to make sure there was any ATF in there. When it came to actually driving the car, we checked it in Drive with the brake on to make sure it was still full when the fluid was circulating inside the converter.
It’s no fun getting sprayed with cooolant, so we checked the radiator, as well as the hoses, for any large leaks. Although the top of the radiator (borrowed from a Mopar application) was bashed in to clear the hood, it still held water, which was good!
You might be cranking for a while when you first try and fire up an engine, so it’s always good to have a fresh battery on hand, a battery charger, or at least another car and a pair of jumper cables. The borrowed battery we used to start the Chevy had 735 cold-cranking amps, which was more than enough to fire the little 305.
One of the few fancy tools we had for our backyard test session was an oil pressure gauge that came off of “some long-forgotten project.” We removed the original sender by the distributor and plugged in the mechanical gauge.
To spot fuel leaks and other potential problems, we started the engine without the air cleaner. Before doing so, we made sure the carburetor stud was tight, and we took the air-filter wing nut off. The last thing you want is to see either of those falling into the carb of a running engine.
Because the ignition key was long gone, we had to do some creative wiring to crank the engine, including using a jumper wire to power to the coil. A regular key ignition will be reinstalled when the vehicle hits the street.
It’s also a good idea to check that the belt(s) is not frayed or cracked. Getting pimp-slapped by a belt flying apart at 2,000 rpm would be no fun.
You can crank an engine all day, but it will never start if your distributor isn’t in the right spot to fire the engine. We checked for No. 1 versus distributor position the old-school way—by pulling out the No. 1 plug, verifying top dead center, and making sure the rotor in the distributor was pointing roughly in the right direction. While this isn’t exact, you can usually get the timing close enough to get the engine to start. Make sure to keep your face away from the carburetor to avoid backfires (ask us how we know).
It’s common for old engines to have gummed-up throttle linkages, so we made sure ours rotated freely and snapped shut when we let go of the throttle arm.
Spark-plug checking tools are available at most auto-parts stores. They plug into the ignition wire just like a regular spark plug, and if clipped to a good connection to ground, will generate a loud, visible spark each time that plug is supposed to fire. When we cranked our engine over, we could actually see the gizmo sparking away, so we knew the ignition system was working, at least.
Filling up the carburetor’s float bowl before trying to start the engine will prevent prolonged cranking needed for a mechanical pump to fill the carburetor itself. We used a syringe to fill our Quadrajet’s float bowl with gas. Remember that gasoline vapors are extremely flammable, so check for leaks. If you see any, shut the engine down immediately.
A see-through fuel filter can be very helpful in making sure fuel is getting up to the carb. While we could see that the fuel pump was working and providing fuel, we also could see rust was making its way into the filter, so the fuel tank would eventually have to be dropped and cleaned (later).
Depending on how long the engine has been sitting, you may want to remove all the spark plugs, add a few drops of oil into each cylinder, and crank the engine for a few revolutions before enabling the ignition, thus preventing a dry-start condition with the piston rings. At this point, we powered up the ignition and fired the engine. Once it started, we immediately checked the mechanical oil pressure gauge, which read about 40 psi with the engine running at 2,000 rpm. Since this was well within the 10–15-psi per 1,000-rpm guideline, we knew we were in good shape.
We’d checked and double-checked everything, and now our 305 was alive! There was a good amount of smoke (which we expected) but no knocking, ticking, or any other internal noises. It also didn’t leak anything after running for a few minutes, which was surprising. While we’re still a long way to having the Chevy be a running and reliable daily driver, and least we know we’re on our way.
Written by Jason Sands – A Backyard Guide to Starting a Neglected Engine