page loaded in 0.047 seconds
| | Site Map | Back Page Art | Back Issues | Privacy and Security | Terms of Use | |
| Home | Features | Articles | Daily Drives | Rear View | Driveway | Directory | Showcase | Classifieds | Store | Games |
Rebuilding a Holley 1 Barrel We'll unravel the mystique surrounding the rebuilding the mysterious Holley 1 Barrel Carburator. Submitted by, Pete Dickerson I drive a 73 Dart Custom four door sedan with the venerable 225 slant six engine. The problem: The smooth and reliable slant six was difficult to start, required many minutes to warm up, and while warming up it missed so badly it shook the entire car. Once the car was warmed up it would idle okay, except that the engine would alternately run smooth, then miss for a few seconds, then run smooth again. My friend Tim, owner of a sweet 71 Scamp, came over to assist with the assessment. Tim was an excellent resource because he had actually rebuilt a one-barrel carburetor before and the car still ran. Plus he's an excellent problem solver. After some fiddling and discussion, we agreed the problem was probably fuel system based, though the intermittent miss really threw us off. Tim and I decided to pull the carb apart. I had purchased a rebuild kit for it a few days before and had since gone over the instructions several times to get familiar with the task, a process I use to make complicated tasks easier. In this case it was having the opposite effect. The simple Holley 1920 carb comes in several versions spanning some 15 years of production. 
The rebuild kit I had obtained was apparently intended to cover all 15 production years. In addition,
the exploded view diagram gave the impression the carb is constructed of hundreds of parts, when in fact
it's only about 40. They don't tell you that. For the basic kitchen table rebuild, you really only
need to worry about a few of them.For reference, I took a couple of digital photos of the carb on the car, then Tim and I proceeded with removing it. Carefully, we laid out each piece on a towel as it came off the carb. Within about a half-hour we had the carb pretty well taken apart. After comparing the pieces we had to the ones in the schematic, a problem quickly became apparent. My carb was missing a spring. The spring is the "pump diaphragm spring", better known as the accelerator pump spring. Unfortunately the kit did not contain a replacement. So we made do with what we had. We replaced the needle and seat, economizer valve assembly, accelerator pump diaphragm, float spring, and the fuel bowl gasket. We put it back together and reinstalled it. The car was cold, so with some trepidation, I twisted the key. It started right up and settled into a decent idle. After it had warmed up a bit, we took it for a short drive around the block. It ran much better, but the off-idle hesitation was still there and performance was still poor. We attributed the remaining problem to the missing spring. Satisfied that we'd given it a good shot, Tim left and I mulled over the next step, finding a spring. 
On my lunch hour a few days later I visited a local carb shop. The man agreed the carb needed to have
the spring and sold me one for $5. No longer sweating removing and cracking open the carb, that night
I installed the spring and took it for a test drive. Yeehaw! What a difference having an accelerator
pump spring makes!Lessons learned? Rebuilding a carb is no longer a scary experience. I have a much better understanding of how carbs work. I used to fear the prospect of pulling a carb off of a car; what with all their hoses, linkages, snap rings, springs and things I don't even have names for. Now this one comes off in about three minutes. Goes on in about four. Fixing the Dart's drivability problem gave me the confidence to attack any problem with another car and fix that one with zero cash outlay. But the biggest lesson learned is, I'm still not done! Probably never will be. And that's the fun. There is always something going on with an old car that needs fixing. You tinker, experiment, talk it over with your car-nut friends, and eventually come up with something that works without breaking you. And at the end of the day, you wash your hands, pop open a cold one, and enjoy the glow of a job well done. Thanks Pete! Don't forget tobuy Tim a cold one! 
page loaded in 0.047 seconds
|