The Stovebolt Site Forums The Shop Area Engine Shop True Confession

Or should I entitle this 'Ignorance Is Bliss'?

I've had my '49 Chevy 1/2 ton for 18 years now and replaced the splash oiler '53 engine with a '56 235 Inline 6 full pressure after four years. At that time I also found a converted 'large head' HEI distributor that had been converted by Langdon's Stovebolt Engine Co. and happily replaced the points distributor. Truck ran great and after a year or two would replace cap and rotor, not really knowing the maintenance schedule or longevity of these parts.

Flash forward to about five years ago when doing my 'couple year replacement' never written in stone, I discover...and here gentlemen you'll want to put your coffee cups down...The rotors commutator, that bent metal springy tab thing that contacts the under side of the distributor cap was gone, well, not gone, just broken off and lying within the distributor. How the he double hockey sticks could it run/start? But it did and it ran for maybe two years like that, must've been arcing.

In addition, around the same time I had noticed that the inner surface of the distrib. cap and the rotor had somewhat of an 'interference fit'. I mean plastic from each of the surfaces were being chewed off, again truck ran and ran well I'd say close to 80K miles in that form. Replaced with new, same thing.

Last week, The Perfect Storm occurred....finished a 14 hour day at work, started truck (a little balky but hey, it's about 20 degrees out) go back into the office to let her warm up. Back in the cab starting off she's balky, gun her and all seems well enough. A mile down the road at an intersection, stalls, won't restart, use the old bump start trick to nurse her off the road.

Triple A, his juice won't start me so I get towed home. Have the next few days off, she's my dd/only vehicle btw, but I'm not going to get suckered into the 'fix it immediately mode'. I sleep on it (didn't get to bed until 3AM that night) and think it through. I am a self taught mechanic that lives with the motto, 'if that guy can fix it I can too'. I didn't have a dad/uncle/neighbor to learn from I just dove in that lake off a dock on a moonless night, and brothers (and you sisters out there too) I'm still doing it.

I know I have compression, got fuel. I pop the cap off the distributor to replace the HEI control module with a spare. At that time I notice that the centrifugal advance (weights, I guess) are stacked and with two hands I play with the spring loaded affair and discover that the whole affair was stacked and not operating properly. I discovered the reason why the cap/rotors were getting chewed up. Readers, I never feel that I lack intelligence when these events occur in life, I feel like an explorer making a brand new (for me at least) discovery. I replaced the module with a spare, buttoned up the dist. and 'Bob's your uncle!' Success, run's great. Took the module to NAPA to happily find out that it was indeed DOA.

Epilogue: I hope you distributor guys come forward to tell me what I had been missing by having that advance mechanism stuck for these many years. I am here on this site to learn and certainly to teach others from my own examples good and in this case years in the making.

Thanks

Just because an HEI has electronics that last three days past forever doesn't mean it is maintenance-free. There are still shaft bushings in the housing to wear, and that centrifugal advance system under the rotor doesn't get lubed unless you take the rotor off periodically and put a little lithium-base grease like Lubriplate on the moving parts. One of the big problems is that the early ones didn't have bushings on the advance weights, just steel-on-steel, and the pivot pins would wear out. Newer ones have brass or plastic bushings and bigger pins. You'll get better performance and/or gas mileage with the centrifugal advance working right. Was it stuck in the "advance" or the "retard" position?

About once a year, pull the rotor and lube the advance system. There should be NO contact between the cap and the rotor except for the rotor center touching the carbon pivot button. A cap and rotor should last at least 50K miles between changes. Have fun!
Jerry

HL, Thanks! IDK, if it was advance or retard, they were 'stacked' close in to the center axis of the distributor.

That would be "retard"- - - -no centrifugal advance at all. You should see a noticeable improvement in performance and fuel economy. Be sure the weights are free to expand and contract with spring pressure bringing the weights back toward center. You should also be able to twist the rotor several degrees clockwise and it will spring back to its original position. That tells you the weights are free to move without taking the rotor off for a visual inspection.
Jerry

Rebuilding a distributor should be in everyone's maintanance schedule. Lots of guys change this, flush that, re-torque these while few ever check thier distributor. It's a moving part and will get wear and tear. Great post cosmo.

Thanks X10 !

Jerry, did a conservative amount of blue caliper grease and worked it in then wiped off excess. Took for a drive out on the Interstate, VERY different. Thanks Jerry.

Thanks Hollow65.

I didn't help, I did see your post at the hamb though. Always a bummer when your ride is acting funny.

Cosmo, reverse story. went to mechanics school in the late sixties. I had a slant 6 dodge engine ready to start and the instructer let us take a break. when we came back from break he told me to start the engine which I did, It started and ran fine and I am proud of my work, The problem was he replaced the coil wire during break with a piece of vacuum tube. Now here is this engine running with a vacuum tube for a coil wire. I had to shut the engine off and he had to inspect his vacuum tube to see what was going on. all i can say it must have been the dust in the hose the spark was traveling on.

Mike, the black color of vacuum tubing is from carbon black powder, the same stuff that makes tires black. Some types of hose have enough carbon in them to conduct high voltage, especially if the coil wire is pretty short. It would have had a BAD miss under load.
Jerry

I just think its impressive you are still using your truck as a daily driver. Thats cool because these trucks are timeless and so solid. I dont know of a truck series that is so tough and runs even when its broke like the Advance Design era. Good story!