The Stovebolt Site Forums The Parking Lot Big Bolts C-80 409 governor

Help guys,
I got the carb for my 409 on the C-80 rebuilt and now I'm trying to get it to run right for the ATHS show in Springfield. I can get it to fire by turning the distributor a little to advance the time. The metal vacuum line from the governor to the distributor keeps it from letting me go far enough. It's very possible that sometime or other, I've had it out and got it one tooth out of time.
My question is, how does the governor work? With it unhooked, I can turn the distributor and get the engine to run, but if I press the pedal, nothing happens. I suspect that without the vacuum hooked up, the primaries don't open. It acts like the linkage isn't connected to the throttle plate. Before I put it on, I was playing with it and the linkage didn't open them either. I assumed they are vacuum operated.

The governor measures velocity through the venturi and cuts the throttle back when the velocity gets too high. Back when we ran gas burners, we disabled them. Drivers could over run the governor down hill any way. Is the carb a tea pot Holley. We called them fire starters.

Move the distributor gear one tooth clockwise and you'll be able to get enough timing advance to keep it running. The 348/409 engines are torque monsters- - - -don't over-rev them or they start swallowing valves. Instead of using the governor, install a good quality, accurate electronic tachometer and keep the RPM under 5500. Drag racers in the early 1960's revved the 409 to almost 7,000 RPM, but they turned a lot of those engines into boat anchors, too. The truck engines don't have the same cam and valve springs as the hotrod car engines, so the redline RPM needs to be a lot lower.
Jerry

The part that really bothers me is why the gas pedal didn't have any effect when the engine was running. That's why I was wondering if the governor controls it.
I had the carb rebuilt by Karb King in Pittsburgh Pa. and I don't have a lot of faith in their ability. They kept it much longer than they said they would, then said they had to order floats. They say they bench flow all carbs but the linkage was bent when I got it back and the butterflies couldn't possibly open. Right now, I'm trying to figure out if the governor is the problem or the carb.If I can figure out how to bypass the governor long enough to see if it runs right, then I'll retime it and get everything back to original shape.

crenwelge,
The carb is a rochester 4 jet. I'm thinking that with the governor pipe unhooked, it's not letting the carb accelerate, like you describe.
I was looking for an easy temporary fix to see if that was the problem before I pull the distributor and retime it. Getting to the distributor means some quality time standing on my head.

It sounds like the rebuilder may have screwed things up. The quick fix would find a passenger car carburetor that fits and came from a car with around 400 cu in. There were hundreds of those 409 Chevs hauling grain from the Texas panhandle to the gulf coast during the 60's. Most of the 409 guys just put another carburetor on them. I ran a GMC that was born with a 371 Olds in those days. I simply threw away the GMC/Holley with a governor and put an Olds Rochester on it and ran along with the 409s. As Jerry mentioned, get a tach and don't worry about a governor. My shift points were between 3800 and 4400. If you are not used to the old things, you probably never well get the revs up that high any way. They get pretty noisy.

If you find a carburetor off of a smaller engine, it will work fine. It may not have top end power, but you probably aren't going to be hauling 60,000 lbs of grain either. A carburetor from a smaller engine will give you better throttle response. One from a larger motor will give you a flat spot on acceleration a be more likely to back fire when it is cold.

I'm not sure exactly what carb your engine was born with. I have a book at home that covers the 80 series of the 80's. But I will be in Germany another week.

The carb is original to the truck. I have a NOS rebuild kit for it, I should have done it myself. I figured out that an AFB will bolt on to the original intake and I have an extra one of those. I'm going to try the rebuilt 4G one more time and if it doesn't work, I'll stick the AFB on long enough to get to the show.
I don't think I would recommend Karb King for a rebuild on a carb that's not mainstream.

OK, the timing was off a tooth, I retimed it and got it started. The gas pedal still didn't have any effect on the engine, even working the linkage under the hood wouldn't make it rev up, so I pulled the carb back off. I knew from tearing my spare carb apart that there was a linkage inside the governor housing so I took off the cover and the governor linkage spring was laying in the bottom. There is a pin that screws into one of several holes and one end of the spring hooks to it. The pin had been cross threaded and not installed all the way and had stripped out so the spring pulled off of it. I moved the pin to the next hole and hooked the spring back up. When I put the carb back on, it ran much better. It's still not right but I'm getting much closer.
I think I know where I won't send another carburetor.