last night I went to the IN Chapter Bunker Hill Drags.. While there and having help setting up my car....cause I keep complaining it feels like a pig like theres more there just aint getting it..... anyways they discover my Advance isn't working at all.. 12* at all RPMS.... it frozen.. not moving nothing. ("71" 455, Edelbrock, 800CFM q-jet,HEI, headers, 2004R, 8.5 w/3:42 Posi) Upon recomendations removing the dist. and cleaning and fixing it is the only way..... what percautions should I take and because of this is there anything else I should look for? Also if possible a link or a diagram of a HEI dist in exploded view would help. thanks We also discovered that the cheap plastic sapcer under the Air cleaner had warped and foemed in not letting the secondaries open all the way.. so now... dunno when hammered and I think they open she starts to drop and run flat.... maybe thats the advance? Again thanks...:TU: Ohh BTW even with all this and my new posi I still blew off my tires from the starting line... so I know now I could use some stickies and a decent tune up... there is a lot left in the ole girl!:grin: Thanks ahead of time for your inputs
Don't pull the whole thing apart. Disassemble the weights and springs. Use some emery cloth to clean up the pins. Then lubricate it with some distributor lube, and reassemble. Pull the weights out, and let them go. They should smoothly go back to their normal retarded position.
Larry, The weights on Chris' car are not frozen, they wiggle around a little pretty freely. It's the advance "plate". You can barely get it to budge when you go to try to twist it. I've never broken one down, so I couldn't help him without doing it myself or looking at a diagram. How do you disassemble one beyond the cap and electronics that just bolt on? A good soaking in diesel would probably work?!
Just tap the roll pin out of the gear, pull the gear off, then the shaft will pull straight out. Soak it to free it up, then lubricate it and reassemble. That should do it.
So pulling it completely out is the only option? And disassemble it.. ? once apart or when taking apart are there any bearings or needles or anything like that I need to be aware of? And what constitutes a good cleaning... ? shouldI change wieight or springs there wasn't any in it when I got it so I put a advance kit in. Also the vacum can should I repalce it? Later
Chris, Yes, you have to pull it out. I don't think there are any needle bearings to worry about. Just pull the shaft, and soak it in some solvent so that it frees up. You can replace the module if you want, and even the pole piece. Just make sure everything moves freely. The Crane adjustable vacuum advance kit comes with springs that are nice. Reuse your weights. (Jegs part # 270-99600-1 GM HEI-22.99) You may want to see about limiting the mechanical advance, so you can run more initial advance. You may be able to use a homemade bushing or have the slot welded up a bit. Once you get it right, you won't believe the difference.
its pretty easy. It will be a little tough because of lacquer on the shaft. I had the same problem and doing what Larry advised fixed it.
Pulling the distrib is a breeze. Here is a good trick I figured out and use religiously... 1) Note where the vacuum advance nipple is pointing. Lay a piece if 2" masking tape across your engine bay in the area that the vacuum nipple is pointing. Then take a Sharpie and mark on the tape exactly where the nipple is pointing. This way when you drop in the distributor it will be timed very close to right where you have it now, so startup will be very easy. Then time it afterward with a timing light. 2) Pull the distributor cap and note where the rotor is pointing. Drape a piece of 2" masking tape across the engine bay and mark it with a sharpie where the rotor is pointing. This way when you drop the distributor back in the rotor will go right back where it came from so you won't be any "teeth off" in your timing. Note which way the rotor rotates when you pull the distributor out. I believe it rotates a little counter-clockwise as it disengages from the cam gear. 3) When the distributor is out DON'T bump the starter or rotate the engine by hand! Doing so will render the tape marks useless, then you'll have to locate TDC on #1 cyl and install the distrib from there. 4) When reinstalling the distrib, if it won't drop right in AND SEAT ALL THE WAY, you COULD push down on the distributor while someone bumps the key, but there is room for error there. Instead, reach down into the timing cover through the distributor hole and, using a long flat blade screwdriver, rotate the oil pump shaft until the distrib will seat. You may have to rotate the oil pump shaft several times before you get it lined up perfectly with the pin in the bottom of the distributor, but you'll eventually get it. Remember, you'll have to start with the rotor pointing a little counterclockwise (I believe) of where it will seat finally, as it will rotate clockwise as you seat the distributor. 5 minutes of prep here will save you an hour of work and aggravation down the road.
Very common problem. Once you get the dist out of the car, tap out the roll pin to get the gear off, pull the shaft out of the housing. This could be fun if it is "gummed up" and most likly is if the advance is stuck. I was using carb cleaner to get while spinning it and slowly pulling it out. Keep working it until it comes out. Dont force it. Then take the advance springs, weights, and e-clips off and use carb cleaner to get it apart if its stuck that bad. I have done about 100 or so over the years and never have used a hammer to get it apart. Once apart, clean it up with some 320grit or so, clean it all out with brake cleaner, lube it up with a good grease (not too much to cause a mess inside the dist cap), put it back together. You would be surprised how simple this dist is. If you really need a diagram, I may be able to find one for a later GM I could email you in pdf, but, it is very simple. Also, take a good look at the pickup coil, it is fairly cheap and easy to replace when it's apart.
Thanks guys for the responses.. looks like i have a job to tackle this weekend..... I got on the stuff nesssary to do it this as stated.. so i hope it goes smoothly.. going to reuse my old current weights and springs... hoping this brings the the nasty .... power robbing demons out of my car :af: so again thanks later
I've been reading this post and decided to go out and get the Crane kit. I used their recommendations as a startup but am looking for any other input. I used the blue/silver spring but I can't seem to get the vac advance/timing set up right. What's the best spring combination, initial timing and total timing for street use? Do I set the timing without the vac advance hooked up and plugged? This is a 72 455 with HEI. MARK
Mark, Total timing to run is 30-36*. No one can tell you exactly, you have to find what your motor likes. Set the timing with the vacuum advance plugged. You must set the total timing, then see where your initial is. You cannot change the amount of mechanical timing in your distributor, not easily anyway. Forget the vacuum advance, and work with the total advance. Get it in below 2500 RPM, and try different total advances. You want the advance in quick without pinging. Once you have that done, limit the vacuum degrees in the cannister to 8-10*, and connect it to manifold or ported vacuum. Do a search on vacuum advance to see how to limit the cannister. This has been posted many times.
